a8cat: handle ASCII tab/backspace/bell in -r mode.

3 files changed, 38 insertions, 18 deletions

diff --git a/a8cat.1 b/a8cat.1
index b6d85a4..42f2017 100644
--- a/a8cat.1
+++ b/a8cat.1
@@ -29,7 +29,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 ..
 .TH "A8CAT" 1 "2024-06-29" "0.2.1" "Urchlay's Atari 8-bit Tools"
 .SH NAME
-a8cat \- Convert Atari 8-bit text to UTF-8 encoded Unicode.
+a8cat \- Convert Atari 8-bit text to UTF-8 encoded Unicode (and back).
 .SH SYNOPSIS
 .sp
 \fIa8cat\fP [\fB\-r\fP] [\fB\-i\fP] [\fB\-u\fP] [\fB\-t\fP] [\fIinfile\fP] [\fIinfile ...\fP]
@@ -53,13 +53,17 @@ a8cat atari.txt > converted.txt
 .UNINDENT
 .UNINDENT
 .sp
-The output is plain UTF\-8 Unicode, without BOM. It will display correctly
-in modern terminals that support Unicode and UTF\-8. If you get lots of
-"empty rectangle" characters, it means your font lacks the glyphs for
-the codepoints; try using the Deja Vu Sans and/or Symbola fonts.
+The output is UTF\-8 Unicode, without BOM, but possibly with
+ANSI/VT\-100 control sequences. It will display correctly in modern
+terminals that support Unicode and UTF\-8. If you get lots of "empty
+rectangle" characters, it means your font lacks the glyphs for the
+codepoints; try using the Deja Vu Sans and/or Symbola fonts.
+.sp
+If you want to pipe the output to a pager, \fBless \-MR\fP is
+recommended. It will display the inverse characters correctly.
 .sp
 It\(aqs even possible to edit the converted text and turn it back into
-ATASCII, if you\(aqre very careful.
+ATASCII, if you\(aqre very careful. See the \fB\-r\fP option, below.
 .sp
 Inverse video (characters codes above \fB$80\fP) are translated using
 the ANSI/VT\-100 reverse video escape sequences. Exception: \fB$9B\fP
@@ -80,8 +84,7 @@ option cannot be converted back to ATASCII with the \fB\-r\fP option.
 .B  \-t
 Text mode. Normally, everything but EOL (\fB$9B\fP) is converted to a
 Unicode graphics character. In text mode, ATASCII tabs, backspace,
-and bells are translated to the ASCII versions. Output created with this
-option cannot be converted back to ATASCII with the \fB\-r\fP option.
+and bells are translated to the ASCII versions.
 .TP
 .B  \-r
 Reverse conversion: Input is UTF\-8, output is ATASCII (or XL ICS, with \fB\-i\fP).
@@ -106,6 +109,10 @@ be any inverse\-video characters in the result.
 .UNINDENT
 .INDENT 0.0
 .TP
+.B \fB\-\-\fP
+End of options; the rest of the arguments are filenames. Use this if you\(aqre
+trying to work with files whose names begin with \fI\-\fP\&.
+.TP
 .B \fB\-h\fP, \fB\-\-help\fP
 Show built\-in help and exit.
 .UNINDENT
diff --git a/a8cat.c b/a8cat.c
index 6395a26..35d8535 100644
--- a/a8cat.c
+++ b/a8cat.c
@@ -72,6 +72,12 @@ int a8revcat(const char *file) {
 			inv = handle_escape_seq(inv, input);
 		} else if(c == '\n') {
 			putchar(0x9b);
+		} else if(c == '\t') {
+			putchar(0x7f);
+		} else if(c == '\b') {
+			putchar(0x7e);
+		} else if(c == '\a') {
+			putchar(0xfd);
 		} else if(c < 0x80) {
 			putchar(c | inv);
 		} else {
diff --git a/a8cat.rst b/a8cat.rst
index 68a4297..7b91fa9 100644
--- a/a8cat.rst
+++ b/a8cat.rst
@@ -2,9 +2,9 @@
 a8cat
 =====
 
---------------------------------------------------
-Convert Atari 8-bit text to UTF-8 encoded Unicode.
---------------------------------------------------
+-------------------------------------------------------------
+Convert Atari 8-bit text to UTF-8 encoded Unicode (and back).
+-------------------------------------------------------------
 
 .. include:: manhdr.rst
 
@@ -26,13 +26,17 @@ goes to standard output; to write to a file, use a command like::
 
   a8cat atari.txt > converted.txt
 
-The output is plain UTF-8 Unicode, without BOM. It will display correctly
-in modern terminals that support Unicode and UTF-8. If you get lots of
-"empty rectangle" characters, it means your font lacks the glyphs for
-the codepoints; try using the Deja Vu Sans and/or Symbola fonts.
+The output is UTF-8 Unicode, without BOM, but possibly with
+ANSI/VT-100 control sequences. It will display correctly in modern
+terminals that support Unicode and UTF-8. If you get lots of "empty
+rectangle" characters, it means your font lacks the glyphs for the
+codepoints; try using the Deja Vu Sans and/or Symbola fonts.
+
+If you want to pipe the output to a pager, **less -MR** is
+recommended. It will display the inverse characters correctly.
 
 It's even possible to edit the converted text and turn it back into
-ATASCII, if you're very careful.
+ATASCII, if you're very careful. See the **-r** option, below.
 
 Inverse video (characters codes above **$80**) are translated using
 the ANSI/VT-100 reverse video escape sequences. Exception: **$9B**
@@ -54,8 +58,7 @@ OPTIONS
 -t
   Text mode. Normally, everything but EOL (**$9B**) is converted to a
   Unicode graphics character. In text mode, ATASCII tabs, backspace,
-  and bells are translated to the ASCII versions. Output created with this
-  option cannot be converted back to ATASCII with the **-r** option.
+  and bells are translated to the ASCII versions.
 
 -r
   Reverse conversion: Input is UTF-8, output is ATASCII (or XL ICS, with **-i**).
@@ -78,6 +81,10 @@ OPTIONS
   back to ATASCII with the **-r** option, but of course there won't
   be any inverse-video characters in the result.
 
+**--**
+  End of options; the rest of the arguments are filenames. Use this if you're
+  trying to work with files whose names begin with *-*.
+
 **-h**, **--help**
   Show built-in help and exit.