.\" You can view this file with:
.\" nroff -man [file]
.\" Adapted from libcurl docs by fandom@telefonica.net
.TH TclCurl 3 "3 October 2011" "TclCurl 7.22.0 "TclCurl Easy Interface"
.SH NAME
TclCurl: - get  a  URL with FTP, FTPS, HTTP, HTTPS, SCP, SFTP, TFTP, TELNET, DICT, FILE, LDAP,
LDAPS, IMAP, IMAPS, POP, POP3, SMTP, SMTPS and gopher syntax.

.SH SYNOPSIS
.BI "curl::init"
.sp
.IB curlHandle " configure " "?options?"
.sp
.IB curlHandle " perform"
.sp
.IB curlHandle " getinfo " curlinfo_option
.sp
.IB curlhandle " cleanup"
.sp
.IB curlhandle " reset"
.sp
.IB curlHandle " duphandle"
.sp
.IB curlHandle " pause"
.sp
.IB curlHandle " resume"
.sp
.BI curl::transfer " ?options?"
.sp
.BI curl::version
.sp
.BI "curl::escape " url
.sp
.BI "curl::unescape " url
.sp
.BI "curl::curlConfig " option
.sp
.BI "curl::versioninfo " option
.sp
.BI "curl::easystrerror " errorCode

.SH DESCRIPTION
The TclCurl extension gives Tcl programmers access to the libcurl
library written by \fBDaniel Stenberg\fP, with it you can download urls,
upload them and many other neat tricks, for more information check
.I http://curl.haxx.se
.SH curl::init
This procedure must be the first one to call, it returns a
.I curlHandle
that you need to use to invoke TclCurl procedures. The init calls intializes
curl and this call MUST have a corresponding call to
.I cleanup
when the operation is completed.
You should perform all your sequential file transfers using the same
curlHandle. This enables TclCurl to use persistent connections when
possible.
.sp
.B RETURN VALUE
.sp
.I curlHandle
to use.
.SH curlHandle configure ?options?
.sp
.B configure
is called to set the options for the transfer. Most operations in TclCurl
have default actions, and by using the appropriate options you can
make them behave differently (as documented). All options are set with
the \fIoption\fP followed by a parameter.
.sp
.B Notes:
the options set with this procedure are valid for the
forthcoming data transfers that are performed when you invoke
.I perform
.sp
The options are not reset between transfers (except where noted), so if
you want subsequent transfers with different options, you must change them
between the transfers. You can optionally reset all options back to the internal
default with \fBcurlHandle reset\fP.
.sp
.I "curlHandle"
is the return code from the
.I "curl::init"
call.
.sp

.B OPTIONS
.sp
.SH Behaviour options

.TP
.B -verbose
Set the parameter to 1 to get the library to display a lot of verbose
information about its operations. Very useful for libcurl and/or protocol
debugging and understanding.

You hardly ever want this set in production use, you will almost always want
this when you debug/report problems. Another neat option for debugging is
.B -debugproc

.TP
.B -header
A 1 tells the extension to include the headers in the body output. This is
only relevant for protocols that actually have headers preceding the data (like HTTP).

.TP
.B -noprogress
A 1 tells the extension to turn on the progress meter
completely. It will also prevent the \fIprogessproc\fP from getting called.

.TP
.B -nosignal
A 1 tells TclCurl not use any functions that install signal
handlers or any functions that cause signals to be sent to the process. This
option is mainly here to allow multi-threaded unix applications to still
set/use all timeout options etc, without risking getting signals.

If this option is set and libcurl has been built with the standard name resolver,
timeouts will not occur while the name resolve takes place. Consider building
libcurl with c-ares support to enable asynchronous DNS lookups, which enables
nice timeouts for name resolves without signals. 

Setting \fInosignal\fP to 1 makes libcurl NOT ask the system to ignore
SIGPIPE signals, which otherwise are sent by the system when trying to send
data to a socket which is closed in the other end. libcurl makes an effort to
never cause such SIGPIPEs to trigger, but some operating systems have no way
to avoid them and even on those that have there are some corner cases when
they may still happen, contrary to our desire. In addition, using
\fIntlm_Wb\fP authentication could cause a SIGCHLD signal to be raised.

.TP
.B -wildcard
Set this option to 1 if you want to transfer multiple files according to a
file name pattern. The pattern can be specified as part of the
\fB-url\fP option, using an fnmatch-like pattern (Shell Pattern
Matching) in the last part of URL (file name).

By default, TClCurl uses its internal wildcard matching implementation. You
can provide your own matching function by the \fB-fnmatchproc\fP option.

This feature is only supported by the FTP download for now.

A brief introduction of its syntax follows:
.RS
.IP "* - ASTERISK"
\&ftp://example.com/some/path/\fB*.txt\fP (for all txt's from the root
directory)
.RE
.RS
.IP "? - QUESTION MARK"
Question mark matches any (exactly one) character.

\&ftp://example.com/some/path/\fBphoto?.jpeg\fP
.RE
.RS
.IP "[ - BRACKET EXPRESSION"
The left bracket opens a bracket expression. The question mark and asterisk have
no special meaning in a bracket expression. Each bracket expression ends by the
right bracket and matches exactly one character. Some examples follow:

\fB[a-zA-Z0\-9]\fP or \fB[f\-gF\-G]\fP \- character interval

\fB[abc]\fP - character enumeration

\fB[^abc]\fP or \fB[!abc]\fP - negation

\fB[[:\fP\fIname\fP\fB:]]\fP class expression. Supported classes are
\fBalnum\fP,\fBlower\fP, \fBspace\fP, \fBalpha\fP, \fBdigit\fP, \fBprint\fP,
\fBupper\fP, \fBblank\fP, \fBgraph\fP, \fBxdigit\fP.

\fB[][-!^]\fP - special case \- matches only '\-', ']', '[', '!' or '^'. These
characters have no special purpose.

\fB[\\[\\]\\\\]\fP - escape syntax. Matches '[', ']' or '\\'.

Using the rules above, a file name pattern can be constructed:

\&ftp://example.com/some/path/\fB[a-z[:upper:]\\\\].jpeg\fP
.RE
.PP

.SH Callback options

.TP
.B -writeproc
Use it to set a Tcl procedure that will be invoked by TclCurl as soon as
there is received data that needs to be saved. The procedure will receive
a single parameter with the data to be saved.

NOTE: you will be passed as much data as possible in all invokes, but you
cannot possibly make any assumptions. It may be nothing if the file is
empty or it may be thousands of bytes.

.TP
.B -file
File in which the transfered data will be saved.

.TP
.B -readproc
Sets a Tcl procedure to be called by TclCurl as soon as it needs to read
data in order to send it to the peer. The procedure has to take one
parameter, which will contain the maximun numbers of bytes to read. It
should return the actual number of bytes read, or '0' if you want to
stop the transfer.

If you stop the current transfer by returning 0 "pre-maturely" (i.e before
the server expected it, like when you've said you will upload N bytes and
you upload less than N bytes), you may experience that the server "hangs"
waiting for the rest of the data that won't come. 

Bugs: when doing TFTP uploads, you must return the exact amount of data
that the callback wants, or it will be considered the final packet by the
server end and the transfer will end there. 

.TP
.B -infile
File from which the data will be transfered.

.TP
.B -progressproc
Name of the Tcl procedure that will invoked by TclCurl  with a frequent
interval during operation (roughly once per second or sooner), no matter if data
is being transfered or not.  Unknown/unused
argument values passed to the callback will be set to zero (like if you
only download data, the upload size will remain 0), the prototype of the
procedure must be:
.sp
.B proc ProgressCallback {dltotal dlnow ultotal ulnow}
.sp
In order to this option to work you have to set the \fBnoprogress\fP
option to '0'. Setting this option to the empty string will restore the
original progress function.

If you transfer data with the multi interface, this procedure will not be
called during periods of idleness unless you call the appropriate procedure
that performs transfers.

You can pause and resume a transfer from within this procedure using the
\fBpause\fP and \fBresume\fP commands.

.TP
.B -writeheader
Pass a the file name to be used to write the header part of the received data to.
The headers are guaranteed to be written one-by-one to this file and
only complete lines are written. Parsing headers should be easy enough using
this.

See also the \f-headervar\fP option to get the headers into an array.

.TP
.B -debugproc
Name of the procedure that will receive the debug data produced by the
.B -verbose
option, it should match the following prototype:
.sp
.B debugProc {infoType data}
.sp
where \fBinfoType\fP specifies what kind of information it is (0 text,
1 incoming header, 2 outgoing header, 3 incoming data, 4 outgoing data,
5 incoming SSL data, 6 outgoing SSL data).

.TP
.B -chunkbgnproc
Name of the procedure that will be called before a file will be transfered by
ftp, it should match the following prototype:
.sp
.B ChunkBgnProc {remains}
.sp

Where remains is the number of files left to be transfered (or skipped)

This callback makes sense only when using the \fB-wildcard\fP option.

.TP
.B -chunkbgnvar
Name of the variable in the global scope that will contain the data of the file about
to be transfered. If you don't use this option '::fileData' will be used.

The available data is: filename, filetype (file, directory, symlink, device block, device char,
named pipe, socket, door or error if it couldn't be identified), time, perm, uid, gid, 
size, hardlinks and flags.

.TP
.B -chunkendproc
Name of the procedure that will be called after a file is transfered (or skipped) 
by ftp, it should match the following prototype:
.sp
.B ChunkEndProc {}
.sp
It should return '0' if everyhting is fine and '1' if some error occurred.

.TP
.B -fnmatchProc
Name of the procedure that will be called instead of the internal wildcard
matching function, it should match the following prototype:
.sp
.B FnMatchProc {pattern string}
.sp
Returns '0' if it matches, '1' if it doesn't.

.SH Error Options

.TP
.B -errorbuffer
Pass a variable name where TclCurl may store human readable error
messages in. This may be more helpful than just the return code from the
command.

.TP
.B -stderr
Pass a file name as parameter. This is the stream to use internally instead
of stderr when reporting errors.
.TP
.B -failonerror
A 1 parameter tells the extension to fail silently if the HTTP code
returned is equal or larger than 400. The default action would be to return
the page normally, ignoring that code.

This method is not fail-safe and there are occasions where non-successful response
codes will slip through, especially when authentication is involved
(response codes 401 and 407). 

You might get some amounts of headers transferred before this situation is detected,
like for when a "100-continue" is received as a response to a POST/PUT and a 401
or 407 is received immediately afterwards.

.SH Network options

.TP
.B -url
The actual URL to deal with.

If the given URL lacks the protocol part ("http://" or "ftp://" etc), it will
attempt to guess which protocol to use based on the given host name. If the
given protocol of the set URL is not supported, TclCurl will return the
\fBunsupported protocol\fP error when you call \fBperform\fP. Use
\fBcurl::versioninfo\fP for detailed info on which protocols are supported.

Starting with version 7.22.0, the fragment part of the URI will not be send as
part of the path, which was the case previously.

\fBNOTE\fP: this is the one option required to be set before \fBperform\fP is called.

.TP
.B -protocols
Pass a list in lowecase of protocols to limit what protocols TclCurl may use in the transfer. This
allows you to have a TclCurl built to support a wide range of protocols but still limit
specific transfers to only be allowed to use a subset of them. 

Accepted protocols are 'http', 'https', 'ftp', 'ftps', 'scp', 'sftp', 'telnet', 'ldap',
\&'ldaps', 'dict', 'file','tftp', 'imap', 'imaps', 'pop', 'pop3', 'smtp', 'smtps', 'gopher'
and 'all'.

.TP
.B -redirprotocols
Pass a list in lowercase of accepted protocols to limit what protocols TclCurl may use in a transfer
that it follows to in a redirect when \fB-followlocation\fP is enabled. This allows you
to limit specific transfers to only be allowed to use a subset of protocols in redirections.

By default TclCurl will allow all protocols except for FILE and SCP. This is a difference
compared to pre-7.19.4 versions which unconditionally would follow to all protocols supported.

.TP
.B -proxy
If you need to use a http proxy to access the outside world, set the
proxy string with this option. To specify port number in this string,
append :[port] to the end of the host name. The proxy string may be
prefixed with [protocol]:// since any such prefix will be ignored.

When you tell the extension to use a HTTP proxy, TclCurl will
transparently convert operations to HTTP even if you specify a FTP
URL etc. This may have an impact on what other features of the library
you can use, such as
.B quote
and similar FTP specifics that will not work unless you tunnel through
the HTTP proxy. Such tunneling  is activated with
.B proxytunnel

TclCurl respects the environment variables http_proxy, ftp_proxy,
all_proxy etc, if any of those are set. The use of this option does
however override any possibly set environment variables.

Setting the proxy string to "" (an empty string) will explicitly disable
the use of a proxy, even if there is an environment variable set for it.

The proxy host string can be specified the exact same way as the proxy
environment variables, include protocol prefix (http://) and embedded
user + password.

Since 7.22.0, the proxy string may be specified with a protocol:// prefix to
specify alternative proxy protocols. Use socks4://, socks4a://, socks5:// or
socks5h:// (the last one to enable socks5 and asking the proxy to do the resolving)
to request the specific SOCKS version
to be used. No protocol specified, http:// and all others will be treated as
HTTP proxies.

.TP
.B -proxyport
Use this option to set the proxy port to use unless it is specified in
the proxy string by \fB-proxy\fP. If not specified, TclCurl will default
to using port 1080 for proxies.

.TP
.B -proxytype
Pass the type of  the  proxy. Available options are 'http', 'http1.0', 'socks4', 'socks4a',
\&'socks5' and 'socks5h', with the HTTP one being the default.

If you set it to \fIhttp1.0\fP, it will only affect how libcurl speaks to a proxy
when CONNECT is used. The HTTP version used for "regular" HTTP requests is instead
controled with \fIhttpversion\fP.

.TP
.B -noproxy
Pass a string, a comma-separated list of hosts which do not use a proxy, if one
is specified. The only wildcard is a single * character, which matches all hosts,
and effectively disables the proxy. Each name in this list is matched as either
a domain which contains the hostname, or the hostname itself. For example, local.com
would match local.com, local.com:80, and www.local.com, but not www.notlocal.com.

.TP
.B -httpproxytunnel
Set the parameter to 1 to get the extension to tunnel all non-HTTP
operations through the given HTTP proxy. Do note that there is a big
difference between using a proxy and tunneling through it. If you don't know what
this means, you probably don't want this tunnel option.

.TP
.B -socks5gssapiservice
Pass thee name of the service. The default service name for a SOCKS5 server is
rcmd/server-fqdn. This option allows you to change it.

.TP
.B -socks5gssapinec
Pass a 1 to enable or 0 to disable. As part of the gssapi negotiation a protection
mode is negotiated. The rfc1961 says in section 4.3/4.4 it should be protected, but
the NEC reference implementation does not. If enabled, this option allows the
unprotected exchange of the protection mode negotiation.

.TP
.B -interface
Pass the interface name to use as outgoing
network interface. The name can be an interface name, an IP address or a host
name.

.TP
.B -localport
This sets the local port number of the socket used for connection. This can
be used in combination with \fB-interface\fP and you are recommended to use
\fBlocalportrange\fP as well when this is set. Valid port numbers
are 1 - 65535.

.TP
.B -localportrange
This is the number of attempts TclCurl should do to find a working local port
number. It starts with the given \fB-localport\fP and adds
one to the number for each retry. Setting this value to 1 or below will make
TclCurl do only one try for each port number. Port numbers by nature
are a scarce resource that will be busy at times so setting this value to something
too low might cause unnecessary connection setup failures.

.TP
.B -dnscachetimeout
Pass the timeout in seconds. Name resolves will be kept in memory for this number
of seconds. Set to '0' to completely disable caching, or '\-1' to make the
cached entries remain forever. By default, TclCurl caches this info for 60 seconds.

The name resolve functions of various libc implementations don't re-read name
server information unless explicitly told so (for example, by calling
 \fIres_init(3)\fP). This may cause TclCurl to keep using the older server even
if DHCP has updated the server info, and this may look like a DNS cache issue.

.TP
.B -dnsuseglobalcache
If the value passed is 1, it tells TclCurl to use a global DNS cache that
will survive between curl handles creations and deletions. This is not thread-safe
as it uses a global varible.

\fBWARNING:\fP this option is considered obsolete. Stop using it. Switch over
to using the share interface instead! See \fItclcurl_share\fP.

.TP
.B -buffersize
Pass your preferred size for the receive buffer in TclCurl. The main point of this
would be that the write callback gets called more often and with smaller chunks.
This is just treated as a request, not an order. You cannot be guaranteed to
actually get the given size.

.TP
.B -port

Pass the number specifying what remote port to connect to, instead of the one specified
in the URL or the default port for the used protocol.

.TP
.B -tcpnodelay

Pass a number to specify whether the TCP_NODELAY option should be set or cleared (1 = set, 0 = clear).
The option is cleared by default. This will have no effect after the connection has been established.

Setting this option will disable TCP's Nagle algorithm. The purpose of this algorithm is to try to
minimize the number of small packets on the network (where "small packets" means TCP segments less
than the Maximum Segment Size (MSS) for the network).

Maximizing the amount of data sent per TCP segment is good because it amortizes the overhead of the
send. However, in some cases (most notably telnet or rlogin) small segments may need to be sent without
delay. This is less efficient than sending larger amounts of data at a time, and can contribute to
congestion on the network if overdone.

.TP
.B -addressscope
Pass a number specifying the scope_id value to use when connecting to IPv6 link-local or site-local
addresses.

.SH Names and Passwords options

.TP
.B -netrc
A 1 parameter tells the extension to scan your
.B ~/.netrc
file to find user name and password for the remote site you are about to
access. Do note that TclCurl does not verify that the file has the correct
properties set (as the standard unix ftp client does), and that only machine
name, user name and password is taken into account (init macros and similar
things are not supported).

You can set it to the following values:
.RS
.TP 5
.B optional
The use of your ~/.netrc file is optional, and information in the URL is to
be preferred. The file will be scanned with the host and user name (to find
the password only) or with the host only, to find the first user name and
password after that machine, which ever information is not specified in
the URL.

Undefined  values  of  the  option  will  have this effect.
.TP
.B ignored
The extension will ignore the file and use only the information in the URL.
This is the default.
.TP
.B required
This value tells the library that use of the file is required, to ignore
the information in the URL, and to search the file with the host only.
.RE

.TP
.B -netrcfile
Pass a string containing the full path name to the file you want to use as .netrc
file. For the option to work, you have to set the \fBnetrc\fP option to
\fBrequired\fP. If this option is omitted, and \fBnetrc\fP is set, TclCurl
will attempt to find the a .netrc file in the current user's home directory.

.TP
.B -userpwd
Pass a string as parameter, which should be [username]:[password] to use for
the connection. Use \fB-httpauth\fP to decide authentication method.

When using NTLM, you can set domain by prepending it to the user name and
separating the domain and name with a forward (/) or backward slash (\\). Like
this: "domain/user:password" or "domain\\user:password". Some HTTP servers (on
Windows) support this style even for Basic authentication.

When using HTTP and \fB-followlocation\fP, TclCurl might perform several
requests to possibly different hosts. TclCurl will only send this user and
password information to hosts using the initial host name (unless
\fB-unrestrictedauth\fP is set), so if TclCurl follows locations to other
hosts it will not send the user and password to those. This is enforced to
prevent accidental information leakage.

.TP
.B -proxyuserpwd
Pass a string as parameter, which should be [username]:[password] to use for
the connection to the HTTP proxy.

.TP 
.B -username
Pass a string with the user name to use for the transfer. It sets the user name
to be used in protocol authentication. You should not use this option together
with the (older) \fB-userpwd\fP option.

In order to specify the password to be used in conjunction with the user name
use the \fB-password\fP option.

.TP
.B -password
Pass a string with the password to use for the transfer.

It should be used in conjunction with the \fB-username\fP option.

.TP
.B -proxyusername
Pass a string with the user name to use for the transfer while connecting to Proxy. 

It should be used in same way as the \fB-proxyuserpwd\fP is used, except that it
allows the username to contain a colon, like in the following example: 
"sip:user@example.com". 

Note the \fB-proxyusername\fP option is an alternative way to set the user name
while connecting to Proxy. It doesn't make sense to use them together.

.TP
.B -proxypassword
Pass a string with the password to use for the transfer while connecting to Proxy. It
is meant to use together with \fB-proxyusername\fP.

.TP
.B -httpauth
Set to the authentication method you want, the available ones are:
.RS
.TP 5
.B basic
HTTP Basic authentication. This is the default choice, and the only
method that is in widespread use and supported virtually everywhere.
It sends the user name and password over the network in plain text,
easily captured by others.

.TP
.B digest
HTTP Digest authentication. Digest authentication is a more secure
way to do authentication over public networks than the regular
old-fashioned Basic method.

.TP
.B digestie
HTTP Digest authentication with an IE flavor. TclCurl will use a special
"quirk" that IE is known to have used before version 7 and that some
servers require the client to use.

.TP
.B gssnegotiate
HTTP GSS-Negotiate authentication. The GSS-Negotiate method, also known as
plain "Negotiate",was designed by Microsoft and is used in their web
applications. It is primarily meant as a support for Kerberos5 authentication
but may be also used along with another authentication methods.

.TP
.B ntlm
HTTP NTLM authentication. A proprietary protocol invented and used by Microsoft.
It uses a challenge-response and hash concept similar to Digest, to prevent the
password from being eavesdropped.

.TP
.B ntlmwb
NTLM delegating to winbind helper. Authentication is performed by a separate
binary application that is executed when needed. The name of the application is
specified at libcurl's compile time but is typically /usr/bin/ntlm_auth.

Note that libcurl will fork when necessary to run the winbind application and kill
it when complete, calling waitpid() to await its exit when done. On POSIX operating
systems, killing the process will cause a SIGCHLD signal to be raised
(regardless of whether \fB-nosignal\fP is set). This behavior is subject to change
in future versions of libcurl. 

.TP
.B any
TclCurl will automatically select the one it finds most secure.

.TP
.B anysafe
It may use anything but basic, TclCurl will automatically select the
one it finds most secure.
.RE

.TP
.B -tlsauthtype
Use it to tell TclCurl which authentication method(s) you want it to use for TLS authentication.
.RS
.TP 5
.TP
.B tlsauthsrp
TLS-SRP authentication. Secure Remote Password authentication for TLS is
defined in RFC 5054 and provides mutual authentication if both sides have a
shared secret. To use TLS-SRP, you must also set the
\fB-tlsauthusername\fP and \fB-tlsauthpassword\fP options.

You need to build libcurl with GnuTLS or OpenSSL with TLS-SRP support for this
to work.
.RE

.TP
.B -tlsauthusername
Pass a string with the username to use for the TLS authentication method specified
with the \fB-tlsauthtype\fP option. Requires that the \fB-tlsauthpassword\fP option
also be set. 

.TP
.B -tlsauthpassword
Pass a string with the password to use for the TLS authentication method specified
with the \fB-tlsauthtype\fP option. Requires that the \fB-tlsauthusername\fP option
also be set. 

.TP
.B -proxyauth
Use it to tell TclCurl which authentication method(s) you want it to use for
your proxy authentication. Note that for some methods, this will induce an
extra network round-trip. Set the actual name and password with the 
\fBproxyuserpwd\fP option.

The methods are those listed above for the \fBhttpauth\fP option. As of this
writing, only Basic and NTLM work.

.SH HTTP options

.TP
.B -autoreferer
Pass an 1 parameter to enable this. When enabled, TclCurl will
automatically set the Referer: field in requests where it follows a Location:
redirect.

.TP
.B -encoding
Sets the contents of the Accept-Encoding: header sent in an HTTP
request, and enables decoding of a response when a Content-Encoding:
header is received.  Three encodings are supported: \fIidentity\fP,
which does nothing, \fIdeflate\fP which requests the server to
compress its response using the zlib algorithm, and \fIgzip\fP which
requests the gzip algorithm.  Use \fIall\fP to send an
Accept-Encoding: header containing all supported encodings.

This is a request, not an order; the server may or may not do it.  This
option must be set or else any unsolicited
encoding done by the server is ignored. See the special file
lib/README.encoding in libcurl docs for details.

.TP
.B -transferencoding
Adds a request for compressed Transfer Encoding in the outgoing HTTP
request. If the server supports this and so desires, it can respond with the
HTTP resonse sent using a compressed Transfer-Encoding that will be
automatically uncompressed by TclCurl on receival.

Transfer-Encoding differs slightly from the Content-Encoding you ask for with
\fB-encoding\fP in that a Transfer-Encoding is strictly meant to
be for the transfer and thus MUST be decoded before the data arrives in the
client. Traditionally, Transfer-Encoding has been much less used and supported
by both HTTP clients and HTTP servers.

.TP
.B -followlocation
An 1 tells the library to follow any
.B Location: header
that the server sends as part of a HTTP header.

This means that the extension will re-send the  same request on the new location
and follow new \fBLocation: headers\fP all the way until no more such headers are
returned. \fB-maxredirs\fP can be used to limit the number of redirects
TclCurl will follow.

Since 7.19.4, TclCurl can limit what protocols it will automatically follow.
The accepted protocols are set with \fB-redirprotocols\fP and it excludes the FILE
protocol by default.

.TP
.B -unrestrictedauth
An 1 parameter tells the extension it can continue
to  send authentication (user+password) when following
locations, even when hostname changed. Note that  this
is  meaningful  only  when setting \fB-followlocation\fP.

.TP
.B -maxredirs
Sets the redirection limit. If that many redirections have been followed,
the next redirect will cause an error. This option only makes sense if the
\fB-followlocation\fP option is used at the same time. Setting the limit
to 0 will make libcurl refuse any redirect. Set it to \-1 for an infinite
number of redirects (which is the default)

.TP
.B -post301
Controls how TclCurl acts on redirects after POSTs that get a 301 or 302 response back.
A "301" as parameter tells the TclCurl to respect RFC 2616/10.3.2 and not convert POST
requests into GET requests when following a 301 redirection. Passing a "302" makes
TclCurl maintain the request method after a 302 redirect. "all" is a convenience string
that activates both behaviours.

The non-RFC behaviour is ubiquitous in web browsers, so the extension does the conversion
by default to maintain consistency. However, a server may require a POST to remain a POST
after such a redirection.

This option is meaningful only when setting \fB-followlocation\fP

.TP
.B -put
An 1 parameter tells the extension to use HTTP PUT a file. The file to put
must be set with \fB-infile\fP and \fB-infilesize\fP.

This option is deprecated starting with version 0.12.1, you should use \fB-upload\fP.

This option does not limit how much data TclCurl will actually send, as that is
controlled entirely by what the read callback returns. 

.TP
.B -post
An 1 parameter tells the library to do a regular HTTP post. This is a
normal application/x-www-form-urlencoded kind, which is the most commonly used
one by HTML forms. See the \fB-postfields\fP option for how to specify the
data to post and \fB-postfieldsize\fP about how to set the data size.

Use the \fB-postfields\fP option to specify what data to post and \fB-postfieldsize\fP
to set the data size. Optionally, you can provide data to POST using the \fB-readproc\fP
options.

You can override the default POST Content-Type: header by setting your own with
\fB-httpheader\fP.

Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue" header.
You can disable this header with \fB-httpheader\fP as usual.

If you use POST to a HTTP 1.1 server, you can send data without knowing the
size before starting the POST if you use chunked encoding. You enable this
by adding a header like "Transfer-Encoding: chunked" with \fB-httpheader\fP.
With HTTP 1.0 or without chunked transfer, you must specify the size in the
request.

When setting \fBpost\fP to an 1 value, it will automatically set
\fBnobody\fP to 0.

NOTE: if you have issued a POST request and want to make a HEAD or GET instead, you must
explicitly pick the new request type using \fB-nobody\fP or \fB-httpget\fP or similar.

.TP
.B -postfields
Pass a string as parameter, which should be the full data to post in a HTTP
POST operation. You must make sure that the data is formatted the way you
want the server to receive it. TclCurl will not convert or encode it for you.
Most web servers will assume this data to be url-encoded.

This is a normal application/x-www-form-urlencoded  kind,
which is the most commonly used one by HTML forms.

If you want to do a zero-byte POST, you need to set
\fB-postfieldsize\fP explicitly to zero, as simply setting
\fB-postfields\fP to NULL or "" just effectively disables the sending
of the specified string. TclCurl will instead assume that the POST
data will be send using the read callback!

Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue" header.
You can disable this header with \fB-httpheader\fP as usual.

\fBNote\fP: to make multipart/formdata posts (aka rfc1867-posts), check out
\fB-httppost\fP option.

.TP
.B -postfieldsize
If you want to post data to the server without letting TclCurl do a strlen()
to measure the data size, this option must be used. Also, when this option is
used, you can post fully binary data which otherwise is likely to fail. If
this size is set to zero, the library will use strlen() to get the data
size.

.TP
.B -httppost
Tells TclCurl you want a multipart/formdata HTTP POST to be made and you
instruct what data to pass on to the server through a
.B Tcl list.

\fBThis is the only case where the data is reset after a transfer.\fP

First, there are some basics you need to understand about multipart/formdata
posts. Each part consists of at least a \fBNAME\fP and a \fBCONTENTS\fP part. If the part
is made for file upload, there are also a stored \fBCONTENT-TYPE\fP and a
\fBFILENAME\fP. Below, we'll discuss on what options you use to set these
properties in the parts you want to add to your post.

The list must contain a \fB'name'\fP tag with the name of the section followed
by a string with the name, there are three tags to indicate the value of
the section: \fB'value'\fP followed by a string with the data to post, \fB'file'\fP
followed by the name of the file to post and \fB'contenttype'\fP with the
type of the data (text/plain, image/jpg, ...), you can also indicate a \fIfalse\fP
file name with \fB'filename'\fP, this is useful in case the server checks if the given
file name is valid, for example, by testing if it starts with 'c:\\' as any real file
name does or if you want to include the full path of the file to post. You can also post
the content of a variable as if it were a file with the options \fB'bufferName'\fP and
\fB'buffer'\fP or use \fB'filecontent'\fP followed by a file name to read that file and
use the contents as data.

Should you need to specify extra headers for the form POST section, use
\fB'contentheader\fP' followed by a list with the headers to post.

Please see 'httpPost.tcl' and 'httpBufferPost.tcl' for examples.

If TclCurl can't set the data to post an error will be returned:
.RS
.TP 5
.B 1
If the memory allocation fails.
.TP
.B 2
If one option is given twice for one form.
.TP
.B 3
If an empty string was given.
.TP
.B 4
If an unknown option was used.
.TP
.B 5
If the some form info is not complete (or error)
.TP
.B 6
If an illegal option is used in an array.
.TP
.B 7
TclCurl has no http support.
.RE

.TP
.B -referer
Pass a string as parameter. It will be used to set the
.B referer
header in the http request sent to the remote server. This can be used to
fool servers or scripts. You can also set any custom header with
.B -httpheader.

.TP
.B -useragent
Pass a string as parameter. It will be used to set the
.B user-agent:
header in the http request sent to the remote server. This can be used to fool
servers or scripts. You can also set any custom header with
.B -httpheader.

.TP
.B -httpheader
Pass a
.B list
with the HTTP headers to pass to the server in your request.
If you add a header that is otherwise generated
and used by TclCurl internally, your added one will be used instead. If you
add a header with no contents as in 'Accept:', the internally used header will
just get disabled. Thus, using this option you can add new headers, replace
and remove internal headers.

The headers included in the linked list must not be CRLF-terminated, because
TclCurl adds CRLF after each header item. Failure to comply with this will
result in strange bugs because the server will most likely ignore part of the
headers you specified.

The first line in a request (containing the method, usually a GET or POST) is
not a header and cannot be replaced using this option. Only the lines
following the request-line are headers. Adding this method line in this list
of headers will only cause your request to send an invalid header.

\fBNOTE\fP:The most commonly replaced headers have "shortcuts" in the  options:
.B cookie, useragent,
and
.B referer.

.TP
.B -http200aliases
Pass a list of aliases to be treated as valid HTTP 200 responses. Some servers
respond with a custom header response line. For example, IceCast servers respond
with "ICY 200 OK". By including this string in your list of aliases, the
response will be treated as a valid HTTP header line such as "HTTP/1.0 200 OK".

\fBNOTE\fP:The alias itself is not parsed for any version strings. Before version
7.16.3, TclCurl used the value set by option \fBhttpversion\fP, but starting with
7.16.3 the protocol is assumed to match HTTP 1.0 when an alias matched.

.TP
.B -cookie
Pass a string as parameter.
It will be used to set a cookie in the http request. The format of
the string should be '[NAME]=[CONTENTS];'. Where NAME is the cookie
name and  CONTENTS is what the cookie should contain.

If  you  need  to  set mulitple cookies, you need to set them all using
a single option and thus you need to concatenate them all in one single string.
Set multiple cookies in one string like this: "name1=content1; name2=content2;"
etc.

This option sets the cookie header explicitly in the outgoing request(s).
If multiple requests are done due to authentication, followed redirections or similar,
they will all get this cookie passed on.

Using this option multiple times will only make the latest string override
the previous ones.

.TP
.B -cookiefile
Pass a string as parameter. It should contain the name of your file holding
cookie data. The cookie data may be in netscape cookie data format or just
regular HTTP-style headers dumped to a file.

Given an empty or non-existing file, this option will enable cookies for this
curl handle, making it understand and parse received cookies and then use
matching cookies in future requests.

If you use this option multiple times, you add more files to read.

.TP
.B -cookiejar
Pass a file name in which TclCurl will dump all internally known cookies
when
.B curlHandle cleanup
is called. If no cookies are known, no file will be created.
Specify "-" to have the cookies written to stdout.

Using this option also enables cookies for this session, so if you, for
example, follow a location it will make matching cookies get sent accordingly.

TclCurl will not and cannot report an error for  this. Using  '\fBverbose\fP'
will get a warning to display, but that is the only visible feedback you get
about this possibly lethal situation.

.TP
.B -cookiesession
Pass an 1 to mark this as a new cookie "session". It will
force TclCurl to ignore all cookies it is about to load that are "session
cookies" from the previous session. By default, TclCurl always stores and
loads all cookies, independent of whether they are session cookies are not.
Session cookies are cookies without expiry date and they are meant to be
alive and existing for this "session" only.

.TP
.B -cookielist
Pass a string with a cookie. The cookie can be either in Netscape / Mozilla
format or just regular HTTP-style header (Set-Cookie: ...) format. If the
cookie engine was not enabled it will be enabled.  Passing a
magic string "ALL" will erase all known cookies while "FLUSH" will write
all cookies known by TclCurl to the file specified by \fB-cookiejar\fP.

.TP
.B -httpget
If set to 1 forces the HTTP request to get back to GET, usable if
POST, PUT or a custom request have been used previously with the
same handle.

When setting \fBhttpget\fP to 1, \fBnobody\fP will automatically be set to 0.

.TP
.B -httpversion
Set to one of the values decribed below, they force TclCurl to use the
specific http versions. It should only be used if you really MUST do
that because of a silly remote server.
.RS
.TP 5
.B none
We do not care about what version the library uses. TclCurl will use whatever
it thinks fit.
.TP
.B 1.0
Enforce HTTP 1.0 requests.
.TP
.B 1.1
Enforce HTTP 1.1 requests.
.TP
.B 2.0
Enforce HTTP version 2 requests.
.TP
.B 2TLS
Enforce version 2 requests for HTTPS, version 1.1 for HTTP.
.TP
.B 2_PRIOR_KNOWLEDGE
Enforce HTTP 2 requests without performing HTTP/1.1 Upgrade first.
.RE

.TP
.B -ignorecontentlength
Ignore the Content-Length header. This is useful for Apache 1.x (and similar
servers) which will report incorrect content length for files over 2
gigabytes. If this option is used, TclCurl will not be able to accurately
report progress, and will simply stop the download when the server ends the
connection.

.TP
.B -httpcontentdecoding
Set to zero to disable content decoding. If set to 1 it is enabled. Note however
that TclCurl has no default content decoding but requires you to use \fBencoding\fP for that.

.TP
.B -httptransferencoding
Set to zero to disable transfer decoding, if set to 1 it is enabled (default). TclCurl does
chunked transfer decoding by default unless this option is set to zero.

.SH SMTP options

.TP 
.B -mailfrom
Pass a string to specify the sender address in a mail when sending an SMTP mail with TclCurl.

.TP
.B -mailrcpt
Pass a list of recipients to pass to the server in your SMTP mail request.

Each recipient in SMTP lingo is specified with angle brackets (<>), but should you not use an
angle bracket as first letter, TclCurl will assume you provide a single email address only and
enclose that with angle brackets for you.

.SH TFTP option

.TP
.B tftpblksize

Specify the block size to use for TFTP data transmission. Valid range as per RFC 2348 is 8-65464 bytes.
The default of 512 bytes will be used if this option is not specified. The specified block size will
only be used pending support by the remote server. If the server does not return an option acknowledgement
or returns an option acknowledgement with no blksize, the default of 512 bytes will be used.

.SH FTP options

.TP
.B -ftpport
Pass a string as parameter. It will be used to
get the IP address to use for the ftp PORT instruction. The PORT instruction
tells the remote server to connect to our specified IP address. The string may
be a plain IP address, a host name, a network interface name (under unix) or
just a '-' to let the library use your systems default IP address. Default FTP
operations are passive, and thus will not use PORT.

The address can be followed by a ':' to specify a port, optionally followed by a '-'
o specify a port range. If the port specified is 0, the operating system will pick
a free port. If a range is provided and all ports in the range are not available,
libcurl will report CURLE_FTP_PORT_FAILED for the handle. Invalid port/range settings
are ignored. IPv6 addresses followed by a port or portrange have to be in brackets.
IPv6 addresses without port/range specifier can be in brackets.

Examples with specified ports:

  eth0:0   192.168.1.2:32000-33000   curl.se:32123   [::1]:1234-4567

You disable PORT again and go back to using the passive version by setting this option to
an empty string.

.TP
.B -quote
Pass a \fBlist\fP list with the FTP or SFTP commands to pass to the server prior to your
ftp request. This will be done before any other FTP commands are issued (even
before the CWD command).If you do not want to transfer any files, set
\fBnobody\fP to '1' and \fBheader\fP to '0'.

Prefix the command with an asterisk (*) to make TclCurl continue even if the command
fails as by default TclCurl will stop.

Disable this operation again by setting an empty string to this option.

Keep in mind the commands to send must be 'raw' ftp commands, for example, to
create a directory you need to send \fBmkd Test\fP, not \fBmkdir Test\fP.

Valid SFTP commands are: chgrp, chmod, chown, ln, mkdir, pwd, rename, rm,
rmdir and symlink. 

.TP
.B -postquote
Pass a \fBlist\fP with the FTP commands to pass to the server after your
ftp transfer request. If you do not want to transfer any files, set
\fBnobody\fP to '1' and \fBheader\fP to '0'.

.TP
.B -prequote
Pass a \fBlist\fP of FTP or SFTP commands to pass to the server after the
transfer type is set.

.TP
.B -dirlistonly
A 1 tells the library to just list the names of files in a
directory, instead of doing a full directory listing that would include file
sizes, dates etc. It works with both FTP and SFTP urls.

This causes an FTP NLST command to be sent. Beware that some FTP servers list
only files in their response to NLST, they might not include subdirectories
and symbolic links.

Setting this option to 1 also implies a directory listing even if the URL
doesn't end with a slash, which otherwise is necessary.

Do NOT use this option if you also use \fB-wildcardmatch\fP as it will
effectively break that feature.

.TP
.B -append
A 1 parameter tells the extension to append to the remote file instead of
overwriting it. This is only useful when uploading to a ftp site.

.TP
.B -ftpusepret
Set to 1 to tell TclCurl to use the EPRT (and LPRT) command when doing
active FTP downloads (which is enabled by '\fBftpport\fP'). Using EPRT means
that it will first attempt to use EPRT and then LPRT before using PORT, if
you pass zero to this option, it will not try using EPRT or LPRT, only plain PORT.

.TP
.B -ftpuseepvs
Set to one to tell TclCurl to use the EPSV command when doing passive FTP
downloads (which it always does by default). Using EPSV means that it will
first attempt to use EPSV before using PASV, but if you pass a zero to this
option, it will not try using EPSV, only plain PASV.

.TP
.B -ftpusepret

Set to one to tell TclCurl to send a PRET command before PASV (and EPSV). Certain
FTP servers, mainly drftpd, require this non-standard command for directory listings
as well as up and downloads in PASV mode. Has no effect when using the active FTP
transfers mode.

.TP
.B -ftpcreatemissingdirs
If set to 1, TclCurl will attempt to create any remote directory that it
fails to CWD into. CWD is the command that changes working directory.

This setting also applies to SFTP-connections. TclCurl will attempt to create
the remote directory if it can't obtain a handle to the target-location. The
creation will fail if a file of the same name as the directory to create
already exists or lack of permissions prevents creation.

If set to 2, TclCurl will retry the CWD command again if the subsequent MKD
command fails. This is especially useful if you're doing many simultanoeus
connections against the same server and they all have this option enabled,
as then CWD may first fail but then another connection does MKD before this
connection and thus MKD fails but trying CWD works

.TP
.B -ftpresponsetimeout
Causes TclCurl to set a timeout period (in seconds) on the amount of time that
the server is allowed to take in order to generate a response message for a
command before the session is considered hung. Note that while TclCurl is waiting
for a response, this value overrides \fBtimeout\fP. It is recommended that if used
in conjunction with \fBtimeout\fP, you set it to a value smaller than \fBtimeout\fP.

.TP
.B -ftpalternativetouser 
Pass a string which will be used to authenticate if the usual FTP "USER user" and
"PASS password" negotiation fails. This is currently only known to be required when
connecting to Tumbleweed's Secure Transport FTPS server using client certificates for
authentication.

.TP
.B -ftpskippasvip
If set to 1, it instructs TclCurl not to use the IP address the
server suggests in its 227-response to TclCurl's PASV command when TclCurl
connects the data connection. Instead TclCurl will re-use the same IP address
it already uses for the control connection. But it will use the port number
from the 227-response.

This option has no effect if PORT, EPRT or EPSV is used instead of PASV.

.TP
.B -ftpsslauth

Pass TclCurl one of the values from below, to alter how TclCurl issues
"AUTH TLS" or "AUTH SSL" when FTP over SSL is activated (see \fB-ftpssl\fP).

You may need this option because of servers like BSDFTPD-SSL from
http://bsdftpd-ssl.sc.ru/ "which won't work properly  when "AUTH SSL" is issued
(although the server responds fine and everything) but requires "AUTH TLS"
instead.

.RS
.TP 5
.B default
Allows TclCurl to decide.
.TP
.B ssl
Try "AUTH SSL" first, and only if that fails try "AUTH TLS".
.TP
.B tls
Try "AUTH TLS" first, and only if that fails try "AUTH SSL".
.RE

.TP
.B -ftpsslccc 
Set it to make TclCurl use CCC (Clear Command Channel). It shuts down the
SSL/TLS layer after authenticating. The rest of the control channel
communication will be unencrypted. This allows NAT routers to follow the
FTP transaction. Possible values are:

.RS
.TP 5
.B none
Do not attempt to use CCC.
.TP
.B passive
Do not initiate the shutdown, wait for the server to do it. Do not send a reply. 
.TP
.B active
Initiate the shutdown and wait for a reply. 
.RE

.TP
.B -ftpaccount
Pass string (or "" to disable). When an FTP server asks for "account data" after
user name and password has been provided, this data is sent off using the ACCT
command.

.TP
.B -ftpfilemethod
It allows three values:
.RS
.TP 5
.B multicwd
The default, TclCurl will do a single CWD operation for each path part in the given
URL. For deep hierarchies this means very many commands. This is how RFC1738 says it
should be done.
.TP
.B nocwd
No CWD at all is done, TclCurl will do SIZE, RETR, STOR, etc and give a full path to
the server.
.TP
.B singlecwd
Make one CWD with the full target directory and then operate on the file "normally".
This is somewhat more standards compliant than 'nocwd' but without the full penalty of 'multicwd'.
.RE

.SH Protocol options

.TP
.B -transfertext
A 1 tells the extension to use ASCII mode for ftp transfers,
instead of the default binary transfer. For win32 systems it does not set the
stdout to binary mode. This option can be usable when transferring text data
between systems with different views on certain characters, such as newlines
or similar.

\fBNOTE:\fP TclCurl does not do a complete ASCII conversion when doing ASCII
transfers over FTP. This is a known limitation/flaw that nobody has
rectified. TclCurl simply sets the mode to ascii and performs a standard
transfer.

.TP
.B -proxytransfermode
If set to 1, TclCurl sets the transfer mode (binary or ASCII) for FTP transfers
done via an HTTP proxy, by appending ;type=a or ;type=i to the URL.
Without this setting, or it being set to 0, the default, \fB-transfertext\fP has
no effect when doing FTP via a proxy. Beware that not all proxies support this feature.

.TP
.B -crlf
If set to '1', TclCurl converts Unix newlines to CRLF newlines on transfers. Disable
this option again by setting the value to '0'.

.TP
.B -range
Pass a string as parameter, which should contain the specified range you
want. It should be in the format
.I "X-Y"
, where X or Y may be left out. HTTP
transfers also support several intervals, separated with commas as in
.I "X-Y,N-M"
Using this kind of multiple intervals will cause the HTTP server to send the
response document in pieces (using standard MIME separation techniques).

Ranges only work on HTTP, FTP and FILE transfers.

.TP
.B -resumefrom
Pass the offset in number of bytes that you want the transfer to start from.
Set this option to 0 to make the transfer start from the beginning
(effectively disabling resume).

For FTP, set this option to \-1 to make the transfer start from the end of the
target file (useful to continue an interrupted upload). 

When doing uploads with FTP, the resume position is where in the local/source
file TclCurl should try to resume the upload from and it will then append the
source file to the remote target file.

.TP
.B -customrequest
Pass a string as parameter. It will be used instead of GET or HEAD when doing
the HTTP request. This is useful for doing DELETE or other more obscure HTTP
requests. Do not do this at will, make sure your server supports the command first.

Note that TclCurl will still act and assume the keyword it would use if you
do not set your custom and it will act according to that. Thus, changing this
to a HEAD when TclCurl otherwise would do a GET might cause TclCurl to act funny,
and similar. To switch to a proper HEAD, use \fB-nobody\fP, to switch to a proper
POST, use \fB-post\fP or \fB-postfields\fP and so on.

.TP
.B -filetime
If you pass a 1, TclCurl will attempt to get the
modification date of the remote document in this operation. This requires that
the remote server sends the time or replies to a time querying command. The
getinfo procedure with the
.I filetime
argument can be used after a transfer to extract the received time (if any).

.TP
.B -nobody
A 1 tells the library not to include the body-part in the
output. This is only relevant for protocols that have a separate header and
body part. On HTTP(S) servers, this will make TclCurl do a HEAD request.

To change request to GET, you should use \fBhttpget\fP. Change request
to POST with \fBpost\fP etc.

.TP
.B -infilesize
When uploading a file to a remote site, this option should be used to tell
TclCurl what the expected size of the infile is.

This option is mandatory for uploading using SCP.

.TP
.B -upload
A 1 tells the library to prepare for an upload. The
\fB-infile\fP and \fB-infilesize\fP options are also interesting for uploads.
If the protocol is HTTP, uploading means using the PUT request unless you tell
TclCurl otherwise.

Using PUT with HTTP 1.1 implies the use of a "Expect: 100-continue" header.
You can disable this header with \fB-httpheader\fP as usual.

If you use PUT to a HTTP 1.1 server, you can upload data without knowing the
size before starting the transfer if you use chunked encoding. You enable this
by adding a header like "Transfer-Encoding: chunked" with \fB-httpheader\fP.
With HTTP 1.0 or without chunked transfer, you must specify the size.

.TP
.B -maxfilesize
This allows you to specify the maximum size (in bytes) of a file to download.
If the file requested is larger than this value, the transfer will not start
and error 'filesize exceeded' (63) will be returned.

NOTE: The file size is not always known prior to download, and for such files
this option has no effect even if the file transfer ends up being larger than
this given limit. This concerns both FTP and HTTP transfers.

.TP
.B -timecondition
This defines how the \fBtimevalue\fP value is treated. You can set this
parameter to \fBifmodsince\fP or \fBifunmodsince\fP.  This feature applies to
HTTP, FTP and FILE.

.TP
.B -timevalue
This should be the time in seconds since 1 jan 1970, and the time will be
used in a condition as specified with \fBtimecondition\fP.


.SH Connection options

.TP
.B -timeout
Pass the maximum time in seconds that you allow
the TclCurl transfer operation to take. Do note that normally, name lookups
may take a considerable time and that limiting the operation to less than a
few minutes risks aborting perfectly normal operations. This option will
cause libcurl to use the SIGALRM to enable time-outing system calls.

In unix-like systems, this might cause signals to be used unless
\fB-nosignal\fP is used.

.TP
.B -timeoutms
Like \fBtimeout\fP but takes a number of milliseconds instead. If libcurl is
built to use the standard system name resolver, that part will still use
full-second resolution for timeouts.

.TP
.B -lowspeedlimit
Pass the speed in bytes per second that the transfer should be below during
.B lowspeedtime
seconds for the extension to consider it too slow and abort.

.TP
.B -lowspeedtime
Pass the time in seconds that the transfer should be below the
.B lowspeedlimit
for the extension to consider it too slow and abort.

.TP
.B -maxsendspeed
Pass a speed in bytes per seconds. If an upload exceeds this speed on cumulative
average during the transfer, the transfer will pause to keep the average rate less
than or equal to the parameter value.  Defaults to unlimited speed.

.TP
.B -maxrecvspeed
Pass a speed in bytes per second. If a download exceeds this speed on cumulative
average during the transfer, the transfer will pause to keep the average rate less
than or equal to the parameter value. Defaults to unlimited speed.

.TP
.B -maxconnects
Sets the persistent connection cache size in all the protocols that support 
persistent conecctions. The set amount will be the maximum amount of simultaneous
connections that TclCurl may cache in this easy handle. Default is 5, and there
isn't much point in changing this value unless you are perfectly aware of how this
work and changes TclCurl's behaviour.

When reaching the maximum limit, TclCurl closes the oldest connection in the cache
to prevent the number of open connections to increase. 

\fBNote\fP: if you have already performed transfers with this curl handle,
setting a smaller
.B maxconnects
than before may cause open connections to unnecessarily get closed.

If you add this easy handle to a multi handle, this setting is not
being acknowledged, instead you must configure the multi handle its own
\fBmaxconnects\fP option.

.TP
.B -connecttimeout
Maximum time in seconds that you allow the
connection to the server to take.  This only limits the connection phase, once
it has connected, this option is of no more use. Set to zero to disable
connection timeout (it will then only timeout on the internal timeouts).

In unix-like systems, this might cause signals to be used unless
\fB-nosignal\fP is set.

.TP
.B -connecttimeoutms
Like \fBconnecttimeout\fP but takes a number of milliseconds instead. If libcurl
is built to use the standard system name resolver, that part will still use
full-second resolution for timeouts.

.TP
.B -ipresolve
Allows an application to select what kind of IP addresses to use when
resolving host names. This is only interesting when using host names
that resolve addresses using more than one version of IP. The allowed
values are:
.RS
.TP 5
.B whatever
Default, resolves addresses to all IP versions that your system allows.
.TP
.B v4
Resolve to ipv4 addresses.
.TP
.B v6
Resolve to ipv6 addresses.
.RE

.TP
.B -resolve
Pass a list of strings with host name resolve information to use for requests with
this handle.

Each single name resolve string should be written using the format
HOST:PORT:ADDRESS where HOST is the name TclCurl will try to resolve, PORT is
the port number of the service where TclCurl wants to connect to the HOST and
ADDRESS is the numerical IP address. If libcurl is built to support IPv6,
ADDRESS can be either IPv4 or IPv6 style addressing.

This option effectively pre-populates the DNS cache with entries for the
host+port pair so redirects and everything that operations against the
HOST+PORT will instead use your provided ADDRESS.

You can remove names from the DNS cache again, to stop providing these fake
resolves, by including a string in the linked list that uses the format
"\-HOST:PORT". The host name must be prefixed with a dash, and the host name
and port number must exactly match what was already added previously.

.TP
.B -usessl
Pass a one of the values from below to make TclCurl use your desired level of SSL for the transfer.
This is for enabling SSL/TLS when you use FTP, SMTP, POP3, IMAP etc.

You can use ftps:// URLs to explicitly switch on SSL/TSL for the control
connection and the data connection.

Alternatively you can set the option to one of these values:

.RS
.TP 5
.B nope
Do not attempt to use SSL
.TP
.B try
Try using SSL, proceed anyway otherwise.
.TP
.B control
Use SSL for the control conecction or fail with "use ssl failed" (64).
.TP
.B all
Use SSL for all communication or fail with "use ssl failed" (64).
.RE

.SH SSL and security options

.TP
.B -sslcert
Pass a string as parameter. The string should be the file name of your certificate.
The default format is "PEM" and can be changed with \fB-sslcerttype\fP.

With NSS this is the nickname of the certificate you wish to authenticate with.
If you want to use a file from the current directory, please precede it with the 
"./" prefix, in order to avoid confusion with a nickname.

.TP
.B -sslcerttype
Pass a string as parameter. The string should be the format of your certificate.
Supported formats are "PEM" and "DER".

.TP
.B -sslkey
Pass a pointer to a zero terminated string as parameter. The string should be
the file name of your private key. The default format is "PEM" and can be
changed with \fB-sslkeytype\fP.

.TP
.B -sslkeytype
Pass a pointer to a zero terminated string as parameter. The string should be
the format of your private key. Supported formats are "PEM", "DER" and "ENG"

\fBNOTE:\fPThe format "ENG" enables you to load the private key from a crypto
engine. in this case \fB-sslkey\fP is used as an identifier passed to
the engine. You have to set the crypto engine with \fB-sslengine\fP. The "DER"
format key file currently does not work because of a bug in OpenSSL.

.TP
.B -keypasswd
Pass a string as parameter. It will be used as the password required to use the
\fB-sslkey\fP or \fB-sshprivatekeyfile\fP private key.

You never need a pass phrase to load a certificate but you need one to load you
private key. 

This option used to be known as \fB-sslkeypasswd\fP and \fB-sslcertpasswd\fP.

.TP
.B -sslengine
Pass a string as parameter. It will be used as the identifier for the crypto
engine you want to use for your private key.

\fBNOTE:\fPIf the crypto device cannot be loaded, an error will be returned.

.TP
.B -sslenginedefault
Pass a 1 to set the actual crypto engine as the default for (asymmetric) crypto operations.

\fBNOTE:\fPIf the crypto device cannot be set, an error will be returned.

.TP
.B -sslversion
Use it to set what version of SSL/TLS to use. The available options are: 
.RS
.TP 5
.B default
The default action. This will attempt to figure out the remote SSL protocol version,
i.e. either SSLv3 or TLSv1 (but not SSLv2, which became disabled by default with 7.18.1). 
.TP
.B tlsv1
Force TLSv1 or later
.TP
.B sslv2
Force SSLv2
.TP
.B sslv3
Force SSLv3
.TP
.B tlsv1_0
Force TLSv1.0 or later
.TP
.B tlsv1_1
Force TLSv1.1 or later
.TP
.B tlsv1_2
Force TLSv1.2 or later
.TP
.B tlsv1_3
Force TLSv1.3 or later
.TP
.B maxdefault
Use the maximum supported TLS version by libcurl or the default value from the SSL library.
.TP
.B maxtlsv1_0
Define maximum supported TLS version as TLSv1.0
.TP
.B maxtlsv1_1
Define maximum supported TLS version as TLSv1.1
.TP
.B maxtlsv1_2
Define maximum supported TLS version as TLSv1.2
.TP
.B maxtlsv1_3
Define maximum supported TLS version as TLSv1.3
.RE

.TP
.B -sslverifypeer
This option determines whether TclCurl verifies the authenticity of the peer's certificate.
A 1 means it verifies; zero means it doesn't. The default is 1. 

When negotiating an SSL connection, the server sends a certificate indicating its identity.
TclCurl verifies whether the certificate is authentic, i.e. that you can trust that the
server is who the certificate says it is. This trust is based on a chain of digital signatures,
rooted in certification authority (CA) certificates you supply.

TclCurl uses a default bundle of CA certificates that comes with libcurl but you can specify
alternate certificates with the \fB-cainfo\fP or the \fB-capath\fP options.

When \fB-sslverifypeer\fP is nonzero, and the verification fails to prove that the certificate
is authentic, the connection fails. When the option is zero, the peer certificate verification
succeeds regardless. 

Authenticating the certificate is not by itself very useful. You typically want to ensure
that the server, as authentically identified by its certificate, is the server you mean to
be talking to, use \fB-sslverifyhost\fP to control that. The check that the host name in
the certificate is valid for the host name you're connecting to is done
independently of this option.

.TP
.B -cainfo
Pass a file naming holding the certificate to verify the peer with. This only
makes sense when used in combination with the \fB-sslverifypeer\fP option, if
it is set to zero \fB-cainfo\fP need not even indicate an accessible file.

This option is by default set to the system path where libcurl's cacert bundle
is assumed to be stored, as established at build time.

When built against NSS this is the directory that the NSS certificate database
resides in.

.TP
.B -issuercert
Pass a string naming a file holding a CA certificate in PEM format. If the option
is set, an additional check against the peer certificate is performed to verify
the issuer is indeed the one associated with the certificate provided by the option.
This additional check is useful in multi-level PKI where one need to enforce the peer
certificate is from a specific branch of the tree.
 
This option makes sense only when used in combination with the \fB-sslverifypeer\fP
option. Otherwise, the result of the check is not considered as failure.

.TP
.B -capath
Pass the directory holding multiple CA certificates to verify the peer with.
If libcurl is built against OpenSSL, the certificate directory must be prepared
using the openssl c_rehash utility.
This only makes sense when used in combination with the  \fB-sslverifypeer\fP
option, if it is set to zero, \fB-capath\fP need not even indicate an accessible
path.

This option apparently does not work in Windows due to some limitation in openssl.

This option is OpenSSL-specific and does nothing if libcurl is built to use GnuTLS.
NSS-powered libcurl provides the option only for backward compatibility.

.TP
.B -crlfile
Pass a string naming a file with the concatenation of CRL (in PEM format) to use in
the certificate validation that occurs during the SSL exchange.
 
When libcurl is built to use NSS or GnuTLS, there is no way to influence the use of
CRL passed to help in the verification process. When built with OpenSSL support,
X509_V_FLAG_CRL_CHECK and X509_V_FLAG_CRL_CHECK_ALL are both set, requiring CRL
check against all the elements of the certificate chain if a CRL file is passed.
 
This option makes sense only when used in combination with the \fB-sslverifypeer\fP
option. 

A specific error code (CURLE_SSL_CRL_BADFILE) is defined with the option. It is returned
when the SSL exchange fails because the CRL file cannot be loaded. A failure in certificate
verification due to a revocation information found in the CRL does not trigger this specific
error.

.TP
.B -sslverifyhost
This option determines whether TclCurl verifies that the server claims to be
who you want it to be.

When negotiating an SSL connection, the server sends a certificate
indicating its identity.

When \fB-sslverifyhost\fP is set to 2, that certificate must indicate
that the server is the server to which you meant to connect, or the
connection fails.

TclCurl considers the server the intended one when the Common Name field
or a Subject Alternate Name field in the certificate matches the host
name in the URL to which you told Curl to connect.

When set to 1, the certificate must contain a Common Name field,
but it does not matter what name it says. (This is not ordinarily a
useful setting).

When the value is 0, the connection succeeds regardless of the names in
the certificate.

The default value for this option is 2.

This option controls the identity that the server \fIclaims\fP. The server
could be lying. To control lying, see \fB-sslverifypeer\fP. If libcurl is built
against NSS and \fB-verifypeer\fP is zero, \fB-verifyhost\fP is ignored.

.TP
.B -certinfo
Set to '1' to enable TclCurl's certificate chain info gatherer. With this enabled, TclCurl
(if built with OpenSSL) will extract lots of information and data about the certificates
in the certificate chain used in the SSL connection. This data can then be to extracted
after a transfer using the \fBgetinfo\fP command and its option \fBcertinfo\fP.

.TP
.B -randomfile
Pass a file name. The file will be used to read from to seed the random engine
for SSL. The more random the specified file is, the more secure the SSL
connection becomes.

.TP
.B -egdsocket
Pass a path name to the Entropy Gathering Daemon socket. It will be used to seed
the random engine for SSL.

.TP
.B -sslcypherlist
Pass a string holding the ciphers to use for the SSL connection. The list must
consists of one or more cipher strings separated by colons. Commas or spaces
are also acceptable separators but colons are normally used, , - and + can be
used as operators. 

For OpenSSL and GnuTLS valid examples of cipher lists include 'RC4-SHA', 'SHA1+DES',
\&'TLSv1' and 'DEFAULT'. The default list is normally set when you compile OpenSSL.

You will find more details about cipher lists on this URL:
    http://www.openssl.org/docs/apps/ciphers.html

For NSS valid examples of cipher lists include 'rsa_rc4_128_md5', 'rsa_aes_128_sha',
etc. With NSS you don't add/remove ciphers. If you use this option then all known
ciphers are disabled and only those passed in are enabled.
 
You'll find more details about the NSS cipher lists on this URL:
<http://directory.fedora.redhat.com/docs/mod_nss.html>

.TP
.B -sslsessionidcache
Pass a 0 to disable TclCurl's use of SSL session-ID caching or a 1 to enable it.
By default all transfers are done using the cache. While nothing ever
should get hurt by attempting to reuse SSL session-IDs, there seem to be broken SSL
implementations in the wild that may require you to disable this in order for you to
succeed.

.TP
.B -krblevel
Set the kerberos security level for FTP, this also enables kerberos awareness.
This is a string, 'clear', 'safe', 'confidential' or 'private'. If the string
is set but does not match one of these, 'private' will be used. Set the string
to NULL to disable kerberos4. Set the string to "" to disable kerberos
support for FTP.

.TP
.B -gssapidelegation
Set the option to 'flag' to allow unconditional GSSAPI credential delegation. The delegation
is disabled by default since 7.21.7. Set the parameter to 'policyflag' to delegate only if
the OK-AS-DELEGATE flag is set in the service ticket in case this feature is supported by the
GSSAPI implementation and the definition of GSS_C_DELEG_POLICY_FLAG was available at compile-time.


.SH SSH options

.TP
.B -sshauthtypes
The allowed types are:

.RS
.TP 5
.B publickey
.TP
.B password
.TP
.B host
.TP
.B keyboard
.TP
.B any
To let TclCurl pick one
.RE

.TP
.B -sshhostpublickeymd5
Pass a string containing 32 hexadecimal digits. The string should be the 128
bit MD5 cheksum of the remote host public key, and TclCurl will reject the
connection to the host unless the md5sums match. This option is only for SCP
and SFTP transfers.

.TP
.B -publickeyfile
Pass the file name for your public key. If not used, TclCurl defaults to using \fB$HOME/.ssh/id_dsa.pub\fP.
HOME environment variable is set, and just \fBid_dsa\fP in the current directory if not. 

.TP
.B -privatekeyfile
Pass the file name for your private key. If not used, TclCurl defaults to using \fB$HOME/.ssh/id_dsa.pub\fP.
HOME environment variable is set, and just \fBid_dsa\fP in the current directory if not.
If the file is password-protected, set the password with \fB-keypasswd\fP.

.TP
.B -sshknownhosts
Pass a string holding the file name of the known_host file to use. The known_hosts
file should use the OpenSSH file format as supported by libssh2. If this file is
specified, TclCurl will only accept connections with hosts that are known and present
in that file, with a matching public key. Use \fB-sshkeyproc\fP to alter the default
behavior on host and key (mis)matching.

.TP
.B -sshkeyproc 
Pass a the name of the procedure that will be called when the known_host matching has
been done, to allow the application to act and decide for TclCurl how to proceed. The
callback will only be called if \fB-knownhosts\fP is also set.

It gets passed a list with three elements, the first one is a list with the type of the
key from the known_hosts file and the key itself, the second is another list with
the type of the key from the remote site and the key itslef, the third tells you
what TclCurl thinks about the matching status. 

The known key types are: "rsa", "rsa1" and "dss", in any other case "unknown" is given.

TclCurl opinion about how they match may be: "match", "mismatch", "missing" or "error".

The procedure must return:
.RS
.TP 5
.B 0
The host+key is accepted and TclCurl will append it to the known_hosts file before
continuing with the connection. This will also add the host+key combo to the known_host
pool kept in memory if it wasn't already present there. The adding of data to
the file is done by completely replacing the file with a new copy, so the permissions of
the file must allow this.
.TP
.B 1
The host+key is accepted, TclCurl will continue with the connection. This will also add
the host+key combo to the known_host pool kept in memory if it wasn't already present
there.
.TP
.B 2
The host+key is rejected. TclCurl will close the connection.
.TP
.B 3
The host+key is rejected, but the SSH connection is asked to be kept alive. This feature
could be used when the app wants to somehow return back and act on the host+key situation
and then retry without needing the overhead of setting it up from scratch again.
.RE

Any other value will cause the connection to be closed.

.SH Other options

.TP
.B -headervar
Name of the Tcl array variable where TclCurl will store the headers returned
by the server.

.TP
.B -bodyvar
Name of the Tcl variable where TclCurl will store the file requested, the file
may contain text or binary data.

.TP
.B -canceltransvar
Name of a Tcl variable, in case you have defined a procedure to call with
\fB-progressproc\fP setting this variable to '1' will cancel the transfer.

.TP
.B -command
Executes the given command after the transfer is done, since it only works
with blocking transfers, it is pretty much useless.

.TP
.B -share
Pass a share handle as a parameter. The share handle must have been created by
a previous call to \fBcurl::shareinit\fP. Setting this option, will make this
handle use the data from the shared handle instead of keeping the data to itself.
See \fItclcurl_share\fP for details.

.TP
.B -newfileperms
Pass a number as a parameter, containing the value of the permissions that will
be assigned to newly created files on the remote server. The default value is 0644,
but any valid value can be used. The only protocols that can use this are sftp://,
scp:// and file://.

.TP
.B -newdirectoryperms
Pass a number as a parameter, containing the value of the permissions that will be
assigned to newly created directories on the remote server. The default value is 0755,
but any valid value can be used. The only protocols that can use this are sftp://, scp://
and file://.

.SH Telnet options

.TP
.B -telnetoptions
Pass a list with variables to pass to the telnet negotiations. The variables should be in
the format <option=value>. TclCurl supports the options 'TTYPE', 'XDISPLOC' and 'NEW_ENV'.
See the TELNET standard for details.

.SH NOT SUPPORTED
Some of the options libcurl offers are not supported, I don't think them
worth supporting in TclCurl but if you need one of them don't forget to
complain:
.sp
.B CURLOPT_FRESH_CONNECT, CURLOPT_FORBID_REUSE, CURLOPT_PRIVATE,
.B CURLOPT_SSL_CTX_FUNCTION, CURLOPT_SSL_CTX_DATA, CURLOPT_SSL_CTX_FUNCTION and
.B CURLOPT_CONNECT_ONLY, CURLOPT_OPENSOCKETFUNCTION, CURLOPT_OPENSOCKETDATA.

.SH curlHandle perform
This procedure is called after the
.B init
and all the
.B configure
calls are made, and will perform the transfer as described in the options.
.sp
It must be called with the same
\fIcurlHandle\fP \fBcurl::init\fP call returned.
You can do any amount of calls to perform while using the same handle. If you
intend to transfer more than one file, you are even encouraged to do
so. TclCurl will then attempt to re-use the same connection for the following
transfers, thus making the operations faster, less CPU intense and using less
network resources. Just note that you will have to use
.I configure
between the invokes to set options for the following perform.
.sp
You must never call this procedure simultaneously from two places using the
same handle. Let it return first before invoking it another time. If
you want parallel transfers, you must use several curl handles.
.TP
.B RETURN VALUE
\&'0' if all went well, non-zero if it didn't. In case of error, if the
.I errorbuffer
was set with
.I configure
there will be a readable error message.
The error codes are:
.IP 1
Unsupported protocol. This build of TclCurl has no support for this protocol.
.IP 2
Very early initialization code failed. This is likely to be and internal error
or a resource problem where something fundamental couldn't get done at init time.
.IP 3
URL malformat. The syntax was not correct.
.IP 4
A requested feature, protocol or option was not found built-in in this libcurl
due to a build-time decision. This means that a feature or option was not
enabled or explicitly disabled when libcurl was built and in order to get it
to function you have to get a rebuilt libcurl.
.IP 5
Couldn't resolve proxy. The given proxy host could not be resolved.
.IP 6
Couldn't resolve host. The given remote host was not resolved.
.IP 7
Failed to connect to host or proxy.
.IP 8
FTP weird server reply. The server sent data TclCurl couldn't parse.
The given remote server is probably not an OK FTP server.
.IP 9
We were denied access to the resource given in the URL. For FTP, this occurs
while trying to change to the remote directory.
.IP 11
FTP weird PASS reply. TclCurl couldn't parse the reply sent to the PASS request.
.IP 13
FTP weird PASV reply, TclCurl couldn't parse the reply sent to the PASV or EPSV
request.
.IP 14
FTP weird 227 format. TclCurl couldn't parse the 227-line the server sent.
.IP 15
FTP can't get host. Couldn't resolve the host IP we got in the 227-line.
.IP 17
FTP couldn't set type. Couldn't change transfer method to either binary or
ascii.
.IP 18
Partial file. Only a part of the file was transfered, this happens when
the server first reports an expected transfer size and then delivers data
that doesn't match the given size.
.IP 19
FTP couldn't RETR file, we either got a weird reply to a 'RETR' command or
a zero byte transfer.
.IP 21
Quote error. A custom 'QUOTE' returned error code 400 or higher (for FTP) or
otherwise indicated unsuccessful completion of the command.
.IP 22
HTTP returned error. This return code only appears if \fB-failonerror\fP is
used and the HTTP server returns an error code that is 400 or higher.
.IP 23
Write error. TclCurl couldn't write data to a local filesystem or an error
was returned from a write callback.
.IP 25
Failed upload failed. For FTP, the server typcially denied the STOR
command. The error buffer usually contains the server's explanation to this.
.IP 26
Read error. There was a problem reading from a local file or an error was returned
from the read callback.
.IP 27
Out of memory. A memory allocation request failed. This should never happen unless
something weird is going on in your computer.
.IP 28
Operation timeout. The specified time-out period was reached according to the
conditions.
.IP 30
The FTP PORT command failed, not all FTP servers support the PORT command,
try  doing a transfer using PASV instead!.
.IP 31
FTP couldn't use REST. This command is used for resumed FTP transfers.
.IP 33
Range error. The server doesn't support or accept range requests.
.IP 34
HTTP post error. Internal post-request generation error.
.IP 35
SSL connect error. The SSL handshaking failed, the error buffer may have
a clue to the reason, could be certificates, passwords, ...
.IP 36
The download could not be resumed because the specified offset was out of the
file boundary.
.IP 37
A file given with FILE:// couldn't be read. Did you checked the permissions?
.IP 38
LDAP cannot bind. LDAP bind operation failed.
.IP 39
LDAP search failed.
.IP 41
A required zlib function was not found.
.IP 42
Aborted by callback. An application told TclCurl to abort the operation.
.IP 43
Internal error. A function was called with a bad parameter.
.IP 45
Interface error. A specified outgoing interface could not be used.
.IP 47
Too many redirects. When following redirects, TclCurl hit the maximum amount, set
your limit with \-\-maxredirs
.IP 48
An option passed to TclCurl is not recognized/known. Refer to the appropriate
documentation. This is most likely a problem in the program that uses
TclCurl. The error buffer might contain more specific information about which
exact option it concerns.
.IP 49
A telnet option string was illegally formatted.
.IP 51
The remote peer's SSL certificate or SSH md5 fingerprint wasn't ok
.IP 52
The server didn't reply anything, which here is considered an error.
.IP 53
The specified crypto engine wasn't found.
.IP 54
Failed setting the selected SSL crypto engine as default!
.IP 55
Failed sending network data.
.IP 56
Failure with receiving network data.
.IP 58
Problem with the local client certificate.
.IP 59
Couldn't use specified SSL cipher.
.IP 60
Peer certificate cannot be authenticated with known CA certificates.
.IP 61
Unrecognized transfer encoding.
.IP 62
Invalid LDAP URL.
.IP 63
Maximum file size exceeded.
.IP 64
SSL use failed.
.IP 65
Sending the data requires a rewind that failed, since TclCurl should
take care of it for you, it means you found a bug.
.IP 66
Failed to initialise ssl engine.
.IP 67
Failed to login, user password or similar was not accepted.
.IP 68
File not found on TFTP server.
.IP 69
There is a permission problem with the TFTP request.
.IP 70
The remote server has run out of space.
.IP 71
Illegal TFTP operation.
.IP 72
Unknown transfer ID.
.IP 73
TFTP file already exists and will not be overwritten.
.IP 74
No such user in the TFTP server and good behaving TFTP servers
should never return this.
.IP 75
Character conversion failed.
.IP 77
Problem with reading the SSL CA cert (path? access rights?).
.IP 78
Remote file not found
.IP 79
Error from the SSH layer
.IP 80
Failed to shut down the SSL connection
.IP 82
Failed to load CRL file
.IP 83
Issuer check failed
.IP 84
The FTP server does not understand the PRET command at all or does not support
the given argument. Be careful when using \fB-customrequest\fP, a
custom LIST command will be sent with PRET CMD before PASV as well.
.IP 85
Mismatch of RTSP CSeq numbers.
.IP 86
Mismatch of RTSP Session Identifiers.
.IP 87
Unable to parse FTP file list (during FTP wildcard downloading).
.IP 88
Chunk callback reported error.

.SH curlHandle getinfo option
Request internal information from the curl session with this procedure.
This procedure is intended to get used *AFTER* a performed transfer,
and can be relied upon only if the \fBperform\fP returns 0.  Use
this function AFTER a performed transfer if you want to get
transfer-oriented data.

The following information can be extracted:

.TP
.B effectiveurl
Returns the last used effective URL.

.TP
.B responsecode
Returns the last received HTTP or FTP code. This will be zero if no server
response code has been received. Note that a proxy's CONNECT response should
be read with \fBhttpconnectcode\fP and not this.

.TP
.B httpconnectcode
Returns the last received proxy response code to a CONNECT request.

.TP
.B filetime
Returns the remote time of the retrieved document (in number of seconds
since 1 jan 1970 in the GMT/UTC time zone). If you get \-1,
it can be because of many reasons (unknown, the server hides it or the
server doesn't support the command that tells document time etc) and the time
of the document is unknown.
.sp
In order for this to work you have to set the \fB-filetime\fP option before
the transfer.

.TP
.B namelookuptime
Returns the time, in seconds, it took from the start until the name resolving
was completed.

.TP
.B connecttime
Returns the time, in seconds, it took from the start until the connect to the
remote host (or proxy) was completed.

.TP
.B appconnecttime
Returns the time, in seconds, it took from the start until the SSL/SSH
connect/handshake to the remote host was completed. This time is most often very
near to the PRETRANSFER time, except for cases such as HTTP pippelining where the
pretransfer time can be delayed due to waits in line for the pipeline and more.

.TP
.B pretransfertime
Returns the time, in seconds, it took from the start until the file transfer
is just about to begin. This includes all pre-transfer commands and
negotiations that are specific to the particular protocol(s) involved.

.TP
.B starttransfertime
Returns the time, in seconds, it took from the start until the first byte
is just about to be transfered. This includes the \fBpretransfertime\fP,
and also the time the server needs to calculate the result.

.TP
.B totaltime
Returns the total transaction time, in seconds, for the previous transfer,
including name resolving, TCP connect etc.

.TP
.B redirecturl
Returns the URL a redirect would take you to if you enable \fBfollowlocation\fP.
This can come very handy if you think using the built-in libcurl redirect logic
isn't good enough for you but you would still prefer to avoid implementing all
the magic of figuring out the new URL.

.TP
.B redirecttime
Returns the total time, in seconds, it took for all redirection steps
including name lookup, connect, pretransfer and transfer before
the final transaction was started, it returns the complete execution
time for multiple redirections, so it returns zero if no redirections
were needed.

.TP
.B redirectcount
Returns the total number of redirections that were actually followed.

.TP
.B numconnects
Returns how many new connections TclCurl had to create to achieve the
previous transfer (only the successful connects are counted). Combined
with \fBredirectcount\fP you are able to know how many times TclCurl
successfully reused existing connection(s) or not. See the Connection
Options of \fBsetopt\fP to see how TclCurl tries to make persistent
connections to save time.

.TP
.B primaryip
Returns the IP address of the most recent connection done with this handle.
This string may be IPv6 if that's enabled.

.TP
.B primaryport
Returns the destination port of the most recent connection done with this handle.

.TP
.B localip
Returns the local (source) IP address of the most recent connection done
with this handle. This string may be IPv6 if that's enabled.

.TP
.B localport
Returns the local (source) port of the most recent connection done with this handle.

.TP
.B sizeupload
Returns the total amount of bytes that were uploaded.

.TP
.B sizedownload
Returns the total amount of bytes that were downloaded. The amount is only
for the latest transfer and will be reset again for each new transfer.

.TP
.B speeddownload
Returns the average download speed, measured in bytes/second, for the complete download.

.TP
.B speedupload
Returns the average upload speed, measured in bytes/second, for the complete upload.

.TP
.B headersize
Returns the total size in bytes of all the headers received.

.TP
.B requestsize
Returns the total size of the issued requests. This is so far only for HTTP
requests. Note that this may be more than one request if followLocation is true.

.TP
.B sslverifyresult
Returns the result of the certification verification that was requested
(using the \-sslverifypeer option to configure).

.TP
.B sslengines
Returns a \fBlist\fP of the OpenSSL crypto-engines supported. Note that engines are
normally implemented in separate dynamic libraries. Hence not all the returned
engines may be available at run-time.

.TP
.B contentlengthdownload
Returns the content-length of the download. This is the value read from the
.B Content-Length:
field. If the size isn't known, it returns \-1.

.TP
.B contentlengthupload
Returns the specified size of the upload.

.TP
.B contenttype
Returns the content-type of the downloaded object. This is the value
read from the Content-Type: field. If you get an empty string, it  means
the server didn't send a valid Content-Type header or that the protocol
used doesn't support this.

.TP
.B httpauthavail
Returns a list with the authentication method(s) available.

.TP
.B proxyauthavail
Returns a list with the authentication method(s) available for your
proxy athentication.

.TP
.B oserrno
Returns the errno value from a connect failure. This value is only set on
failure, it is no reset after a successfull operation.

.TP
.B cookielist
Returns a list of all cookies TclCurl knows (expired ones, too). If there
are no cookies (cookies for the handle have not been enabled or simply
none have been received) the list will be empty.

.TP
.B ftpentrypath 
Returns a string holding the path of the entry path. That is the initial path
TclCurl ended up in when logging on to the remote FTP server. Returns an empty
string if something is wrong.

.TP
.B certinfo
Returns list with information about the certificate chain, assuming you had the
\fB-certinfo\fP option enabled when the previous request was done. The list
first item reports how many certs it found and then you can extract info for each
of those certs by following the list. The info chain is provided in a series of data
in the format "name:content" where the content is for the specific named data.

NOTE: this option is only available in libcurl built with OpenSSL support.

.TP
.B conditionunmet
Returns the number 1 if the condition provided in the previous request
didn't match (see \fItimecondition\fP), you will get a zero if the condition
instead was met.

.SH curlHandle cleanup
This procedure must be the last one to call for a curl session. It is the
opposite of the
.I curl::init
procedure and must be called with the same
.I curlhandle
as input as the curl::init call returned.
This will effectively close all connections TclCurl has used and possibly
has kept open until now. Don't call this procedure if you intend to transfer
more files.

.SH curlHandle reset

Re-initializes all options previously set on a specified handle to the
default values.

This puts back the handle to the same state as it was in when it was just
created with curl::init.

It does not change the following information kept in the handle: live
connections, the Session ID cache, the DNS cache, the cookies and shares.

.SH curlHandle duphandle
This procedure will return a new curl handle, a duplicate,
using all the options previously set in the input curl handle.
Both handles can subsequently be used independently and
they must both be freed with
.B cleanup.
The new handle will not inherit any state information,
connections, SSL sessions or cookies.
.TP
.B RETURN VALUE
A new curl handle or an error message if the copy fails.

.SH curlHandle pause
You can use this command from within a progress callback procedure
to pause the transfer.

.SH curlHandle resume
Resumes a transfer paused with \fBcurlhandle pause\fP

.SH curl::transfer
In case you do not want to use persistent connections you can use this
command, it takes the same arguments as the \fIcurlHandle\fP \fBconfigure\fP
and will init, configure, perform and cleanup a connection for you.

You can also get the \fIgetinfo\fP information by using \fI-infooption variable\fP
pairs, after the transfer \fIvariable\fP will contain the value that would have
been returned by \fI$curlHandle getinfo option\fP.
.TP
.B RETURN VALUE
The same error code \fBperform\fP would return.

.SH curl::version
Returns a string with the version number of tclcurl, libcurl and some of
its important components (like OpenSSL version).
.TP
.B RETURN VALUE
The string with the version info.

.SH curl::escape url
This procedure will convert the given input string to an URL encoded string and
return that. All input characters that are not a-z,
A-Z or 0-9 will be converted to their "URL escaped" version (%NN where NN is a
two-digit hexadecimal number)
.TP
.B RETURN VALUE
The converted string.
.SH curl::unescape url
This procedure will convert the given URL encoded input string to a "plain
string" and return that. All input characters that
are URL encoded (%XX where XX is a two-digit hexadecimal number) will be
converted to their plain text versions.
.TP
.B RETURN VALUE
The string unencoded.

.SH curl::curlConfig option
Returns some information about how you have
.B cURL
installed.

.TP
.B -prefix
Returns the directory root where you installed
.B cURL
.TP
.B -feature
Returns a list containing particular main features the installed
.B libcurl
was built with. The list may include SSL, KRB4 or IPv6, do not
assume any particular order.
.TP
.B -vernum
Outputs  version  information  about  the installed libcurl, in
numerical mode.  This outputs the  version  number,  in hexadecimal,
with 8 bits for each part; major, minor, patch. So  that  libcurl
7.7.4 would appear as 070704 and libcurl 12.13.14 would appear as
0c0d0e...

.SH curl::versioninfo option
Returns information about various run-time features in TclCurl.

Applications should use this information to judge if things are possible to do
or not, instead of using compile-time checks, as dynamic/DLL libraries can be
changed independent of applications.

.TP
.B -version
Returns the version of libcurl we are using.

.TP
.B -versionnum
Retuns the version of libcurl we are using in hexadecimal with 8 bits for each
part; major, minor, patch. So  that  libcurl 7.7.4 would appear as 070704 and
libcurl 12.13.14 would appear as 0c0d0e... Note that the initial zero might be
omitted.

.TP
.B -host
Returns a string with the host information as discovered by a configure
script or set by the build environment.

.TP
.B -features
Returns a list with the features compiled into libcurl, the possible elements are:
.RS
.TP 5
.B ASYNCHDNS
Libcurl was built with support for asynchronous name lookups, which allows
more exact timeouts (even on Windows) and less blocking when using the multi
interface.
.TP
.B CONV
Libcurl was built with support for character conversions.
.TP
.B DEBUG
Libcurl was built with extra debug capabilities built-in. This is mainly of
interest for libcurl hackers. 
.TP
.B GSSNEGOTIATE
Supports HTTP GSS-Negotiate.
.TP
.B IDN
Supports IDNA, domain names with international letters.
.TP
.B IPV6
Supports IPv6.
.TP
.B KERBEROS4
Supports kerberos4 (when using FTP).
.TP
.B LARGEFILE
Libcurl was built with support for large files.
.TP
.B LIBZ
Supports HTTP deflate using libz.
.TP
.B NTML
Supports HTTP NTLM
.TP
.B SPNEGO
Libcurl was built with support for SPNEGO authentication (Simple and Protected
GSS-API Negotiation Mechanism, defined in RFC 2478)
.TP
.B SSL
Supports SSL (HTTPS/FTPS)
.TP
.B SSPI
Libcurl was built with support for SSPI. This is only available on Windows and
makes libcurl use Windows-provided functions for NTLM authentication. It also
allows libcurl to use the current user and the current user's password without
the app having to pass them on.
.TP
.B TLSAUTH_SRP
Libcurl was built with support for TLS-SRP.
.B NTLM_WB
Libcurl was built with support for NTLM delegation to a winbind helper.
.RE
Do not assume any particular order.

.TP
.B -sslversion
Returns a string with the OpenSSL version used, like OpenSSL/0.9.6b.

.TP
.B -sslversionnum
Returns the numerical OpenSSL version value as defined by the OpenSSL project.
If libcurl has no SSL support, this is 0.

.TP
.B -libzversion
Returns a string, there is no numerical  version, for example: 1.1.3.

.TP
.B -protocols
Lists what particular protocols the installed TclCurl was built to support.
At the time of writing, this list may include HTTP, HTTPS, FTP, FTPS,
FILE, TELNET, LDAP, DICT. Do not assume any particular order. The protocols
will be listed using uppercase. There may be none, one or several protocols
in the list.

.SH curl::easystrerror errorCode
This procedure returns a string describing the error code passed in the argument.

.SH "SEE ALSO"
.I curl, The art of HTTP scripting (at http://curl.haxx.se), RFC 2396,
