gexecutableprocessor.cpp
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1 //
2 // Copyright (C) 2001-2013 Graeme Walker <graeme_walker@users.sourceforge.net>
3 //
4 // This program is free software: you can redistribute it and/or modify
5 // it under the terms of the GNU General Public License as published by
6 // the Free Software Foundation, either version 3 of the License, or
7 // (at your option) any later version.
8 //
9 // This program is distributed in the hope that it will be useful,
10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 // GNU General Public License for more details.
13 //
14 // You should have received a copy of the GNU General Public License
15 // along with this program. If not, see <http://www.gnu.org/licenses/>.
16 // ===
17 //
18 // gexecutableprocessor.cpp
19 //
20 
21 #include "gdef.h"
22 #include "gsmtp.h"
23 #include "gprocess.h"
24 #include "gnewprocess.h"
25 #include "gexecutableprocessor.h"
26 #include "gstr.h"
27 #include "groot.h"
28 #include "glog.h"
29 
31  m_exe(exe) ,
32  m_ok(true) ,
33  m_cancelled(false) ,
34  m_repoll(false)
35 {
36 }
37 
39 {
40 }
41 
43 {
44  return m_cancelled ;
45 }
46 
48 {
49  return m_repoll ;
50 }
51 
53 {
54  if( m_ok ) return std::string() ;
55  const std::string default_ = "pre-processing failed" ;
56  return m_text.empty() ? default_ : m_text ;
57 }
58 
59 bool GSmtp::ExecutableProcessor::process( const std::string & path )
60 {
61  int exit_code = preprocessCore( G::Path(path) ) ;
62 
63  // zero, special or failure
64  bool is_zero = exit_code == 0 ;
65  bool is_special = exit_code >= 100 && exit_code <= 107 ;
66  bool is_failure = !is_zero && !is_special ;
67  if( is_failure )
68  {
69  G_WARNING( "GSmtp::ExecutableProcessor::preprocess: pre-processing failed: exit code " << exit_code ) ;
70  }
71 
72  // set special-repoll and special-cancelled flags
73  m_repoll = is_special && ((exit_code-100)&2) != 0 ;
74  m_cancelled = is_special && ((exit_code-100)&1) == 0 ;
75 
76  // treat special as ok, except for special-cancelled
77  m_ok = is_zero || ( is_special && !m_cancelled ) ;
78  return m_ok ;
79 }
80 
81 int GSmtp::ExecutableProcessor::preprocessCore( const G::Path & path )
82 {
83  G_LOG( "GSmtp::ExecutableProcessor::preprocess: running \"" << m_exe.displayString() << " " << path << "\"" ) ;
84 
85  // add the path of the content file as a trailing command-line parameter
86  G::Strings args( m_exe.args() ) ;
87  args.push_back( path.str() ) ;
88 
89  // run the program
90  std::string raw_output ;
91  int exit_code = G::NewProcess::spawn( G::Root::nobody() , m_exe.exe() , args ,
92  &raw_output , 127 , execErrorHandler ) ;
93 
94  // search the output for diagnostics
95  m_text = parseOutput( raw_output ) ;
96  G_LOG( "GSmtp::ExecutableProcessor::preprocess: exit status " << exit_code << " (\"" << m_text << "\")" ) ;
97 
98  return exit_code ;
99 }
100 
101 std::string GSmtp::ExecutableProcessor::execErrorHandler( int error )
102 {
103  // (this runs in the fork()ed child process)
104  std::ostringstream ss ;
105  ss << "<<exec error " << error << ": " << G::Str::lower(G::Process::strerror(error)) << ">>" ;
106  return ss.str() ;
107 }
108 
109 std::string GSmtp::ExecutableProcessor::parseOutput( std::string s ) const
110 {
111  G_DEBUG( "GSmtp::ExecutableProcessor::parseOutput: in: \"" << G::Str::printable(s) << "\"" ) ;
112 
113  const std::string start_1("<<") ;
114  const std::string end_1(">>") ;
115  const std::string start_2("[[") ;
116  const std::string end_2("]]") ;
117 
118  std::string result ;
119  while( G::Str::replaceAll( s , "\r\n" , "\n" ) ) ;
120  G::Str::replaceAll( s , "\r" , "\n" ) ;
121  G::Strings lines ;
122  G::Str::splitIntoFields( s , lines , "\n" ) ;
123  for( G::Strings::iterator p = lines.begin() ; p != lines.end() ; ++p )
124  {
125  std::string line = *p ;
126  size_t pos_start = line.find(start_1) ;
127  size_t pos_end = line.find(end_1) ;
128  if( pos_start != 0U )
129  {
130  pos_start = line.find(start_2) ;
131  pos_end = line.find(end_2) ;
132  }
133  if( pos_start == 0U && pos_end != std::string::npos )
134  {
135  result = G::Str::printable(line.substr(2U,pos_end-2U)) ;
136  break ;
137  }
138  }
139  G_DEBUG( "GSmtp::ExecutableProcessor::parseOutput: out: \"" << G::Str::printable(result) << "\"" ) ;
140  return result ;
141 }
142 
144 {
145  return m_done_signal ;
146 }
147 
149 {
150  // no-op -- not asynchronous
151 }
152 
153 void GSmtp::ExecutableProcessor::start( const std::string & message_file )
154 {
155  // not asynchronous -- process() synchronously and emit the done signal
156  bool ok = process( message_file ) ;
157  m_done_signal.emit( ok ) ;
158 }
159 
ExecutableProcessor(const G::Executable &)
Constructor.
static int spawn(Identity nobody, const Path &exe, const Strings &args, std::string *pipe_result_p=NULL, int error_return=127, std::string(*error_decode_fn)(int)=0)
Runs a command in an unprivileged child process.
std::string str() const
Returns the path string.
Definition: gpath.cpp:135
static std::string printable(const std::string &in, char escape= '\\')
Returns a printable represention of the given input string.
Definition: gstr.cpp:507
virtual void start(const std::string &path)
Final override from from GSmtp::Processor.
static Identity nobody()
Returns the 'nobody' identity.
Definition: groot.cpp:82
std::list< std::string > Strings
A std::list of std::strings.
Definition: gstrings.h:39
static void splitIntoFields(const std::string &in, Strings &out, const std::string &seperators, char escape= '\0', bool discard_bogus_escapes=true)
Splits the string into fields.
Definition: gstr.cpp:765
A structure representing an external program, holding a path and a set of arguments.
Definition: gexecutable.h:43
virtual std::string text() const
Final override from from GSmtp::Processor.
static std::string lower(const std::string &s)
Returns a copy of 's' in which all uppercase characters have been replaced by lowercase characters...
Definition: gstr.cpp:408
static unsigned int replaceAll(std::string &s, const std::string &from, const std::string &to)
Does a global replace on string 's', replacing all occurences of sub-string 'from' with 'to'...
Definition: gstr.cpp:78
virtual void abort()
Final override from from GSmtp::Processor.
#define G_LOG(expr)
Definition: glog.h:98
virtual ~ExecutableProcessor()
Destructor.
#define G_DEBUG(expr)
Definition: glog.h:95
virtual bool cancelled() const
Final override from from GSmtp::Processor.
virtual G::Signal1< bool > & doneSignal()
Final override from from GSmtp::Processor.
virtual bool repoll() const
Final override from from GSmtp::Processor.
A Path object represents a file system path.
Definition: gpath.h:44
static std::string strerror(int errno_)
Translates an 'errno' value into a meaningful diagnostic string.
#define G_WARNING(expr)
Definition: glog.h:107