Add new command line options --color and --no-color

doc/boxes.1.in

@@ -6,9 +6,7 @@
 boxes \- text mode box and comment drawing filter
 .SH SYNOPSIS
 .B boxes
-[\-hlmrv] [\-a\ format] [\-d\ design] [\-e\ eol] [\-f\ file] [\-i\ indent]
-[\-k\ bool] [\-n\ encoding] [\-p\ pad] [\-q query] [\-s\ size] [\-t\ tabopts]
-[infile [outfile]]
+[options] [infile [outfile]]
 .SH DESCRIPTION
 .I Boxes
 is a text filter which can draw any kind of box around its input text. Box
@@ -33,7 +31,7 @@ Options offered by
 .I boxes
 are the following:
 .TP 0.6i
-\fB\-a\fP \fIstring\fP, \fB\-\-align\fP=\fIstring\fP
+\fB\-a\fP \fIformat\fP, \fB\-\-align\fP=\fIformat\fP
 Alignment/positioning of text inside box. This option takes a format string
 argument which is read from left to right. The format string may not
 contain whitespace and must consist of one or more of the following
@@ -127,6 +125,30 @@ may of course be used in conjunction with any of the other options. By default,
 is not specified.
 .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 .TP 0.6i
+\fB\-\-color\fP, \fB\-\-no\-color\fP
+Printing of color codes. Box designs and the text inside a box may contain ANSI
+color codes, sometimes called "escape sequences". In this way, boxes and text
+can be colored.
+.br
+Whether these escape sequences are printed by
+.I boxes
+is normally determined by the terminal capabilities (default). Using
+\fB\-\-color\fP,
+.I boxes
+can be told to always output escape sequences even if it thinks the terminal
+may not understand them. Using \fB\-\-no\-color\fP, escape sequences will
+never be printed.
+
+Of course, even with
+.B \-\-color\fP,
+a box will only appear colored if it is already defined with colors. In case
+you want to auto-color some text that isn't yet, take a look at
+.I lolcat\fP.
+.br
+These options consider all escape sequences to be color codes. Any other
+escape sequences present will be printed or removed along with the color codes.
+.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+.TP 0.6i
 \fB\-d\fP \fIstring\fP, \fB\-\-design\fP=\fIstring\fP
 Design selection. The one argument of this option is the name of the design to
 use, which may either be a design's primary name or any of its alias names.
@@ -312,10 +334,12 @@ influence the box size (such as
 By default, the smallest possible box is created around the text.
 .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 .TP 0.6i
-\fB\-t\fP \fIstring\fP, \fB\-\-tabs\fP=\fIstring\fP
+\fB\-t\fP \fItabopts\fP, \fB\-\-tabs\fP=\fItabopts\fP
 Tab handling. This option controls how tab characters in the input text are
-handled. The option string must always begin with a positive integer number
-indicating the distance between tab stops, sometimes called "spaces per tab".
+handled. The
+.I tabopts
+must always begin with a positive integer number indicating the distance
+between tab stops, sometimes called "spaces per tab".
 .br
 Immediately following the tab distance, an optional character can be appended,
 telling

src/cmdline.c

@@ -84,6 +84,8 @@ void usage_long(FILE *st)
     fprintf(st, "Usage:  %s [options] [infile [outfile]]\n", PROJECT);
     fprintf(st, "  -a, --align <fmt>     Alignment/positioning of text inside box [default: hlvt]\n");
     fprintf(st, "  -c, --create <str>    Use single shape box design where str is the W shape\n");
+    fprintf(st, "      --color           Force output of ANSI sequences if present\n");
+    fprintf(st, "      --no-color        Force monochrome output (no ANSI sequences)\n");
     fprintf(st, "  -d, --design <name>   Box design [default: first one in file]\n");
     fprintf(st, "  -e, --eol <eol>       Override line break type (experimental) [default: %s]\n",
                                          strcmp(EOL_DEFAULT, "\r\n") == 0 ? "CRLF" : "LF");
@@ -588,6 +590,7 @@ static void print_debug_info(opt_t *result)
                     result->halign ? result->halign : '?', result->valign ? result->valign : '?');
             fprintf (stderr, "- Line justification (-a): \'%c\'\n", result->justify ? result->justify : '?');
             fprintf (stderr, "- Design Definition W shape (-c): %s\n", result->cld ? result->cld : "n/a");
+            fprintf (stderr, "- Color mode: %d\n", result->color);
             fprintf (stderr, "- Line terminator used (-e): %s\n",
                 strcmp(result->eol, "\r\n") == 0 ? "CRLF" : (strcmp(result->eol, "\r") == 0 ? "CR" : "LF"));
             fprintf (stderr, "- Explicit config file (-f): %s\n", result->f ? result->f : "no");
@@ -639,6 +642,8 @@ opt_t *process_commandline(int argc, char *argv[])
     const struct option long_options[] = {
         { "align",         required_argument, NULL, 'a' },
         { "create",        required_argument, NULL, 'c' },
+        { "color",         no_argument,       NULL, OPT_COLOR },
+        { "no-color",      no_argument,       NULL, OPT_NO_COLOR },
         { "design",        required_argument, NULL, 'd' },
         { "eol",           required_argument, NULL, 'e' },
         { "config",        required_argument, NULL, 'f' },
@@ -677,6 +682,14 @@ opt_t *process_commandline(int argc, char *argv[])
                 }
                 break;
             
+            case OPT_COLOR:
+                result->color = force_ansi_color;
+                break;
+
+            case OPT_NO_COLOR:
+                result->color = force_monochrome;
+                break;
+
             case 'd':
                 if (design_choice(result, optarg) != 0) {
                     return NULL;

src/cmdline.h

@@ -29,6 +29,8 @@
 /*
  * Some ints that define return values for getopt_long() to indicate certain long options.
  */
+#define OPT_COLOR 1001
+#define OPT_NO_COLOR 1002
 #define OPT_KILLBLANK 1003
 #define OPT_NO_KILLBLANK 1004