contrib/grep/lib/colorize-w32.c

   1 /* Output colorization on MS-Windows.
   2    Copyright 2011-2015 Free Software Foundation, Inc.
   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, or (at your option)
   7    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, write to the Free Software
  16    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
  17    02110-1301, USA.  */
  18
  19 /* Written by Eli Zaretskii.  */
  20
  21 #include <config.h>
  22
  23 #include "colorize.h"
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <unistd.h>
  29
  30 #undef DATADIR  /* conflicts with objidl.h, which is included by windows.h */
  31 #include <windows.h>
  32
  33 static HANDLE hstdout = INVALID_HANDLE_VALUE;
  34 static SHORT norm_attr;
  35
  36 /* Initialize the normal text attribute used by the console.  */
  37 void
  38 init_colorize (void)
  39 {
  40   CONSOLE_SCREEN_BUFFER_INFO csbi;
  41
  42   hstdout = GetStdHandle (STD_OUTPUT_HANDLE);
  43   if (hstdout != INVALID_HANDLE_VALUE
  44       && GetConsoleScreenBufferInfo (hstdout, &csbi))
  45      norm_attr = csbi.wAttributes;
  46   else
  47     hstdout = INVALID_HANDLE_VALUE;
  48 }
  49
  50 /* Return non-zero if we should highlight matches in output.  */
  51 int
  52 should_colorize (void)
  53 {
  54   /* $TERM is not normally defined on DOS/Windows, so don't require
  55      it for highlighting.  But some programs, like Emacs, do define
  56      it when running Grep as a subprocess, so make sure they don't
  57      set TERM=dumb.  */
  58   char const *t = getenv ("TERM");
  59   return ! (t && strcmp (t, "dumb") == 0);
  60 }
  61
  62 /* Convert a color spec, a semi-colon separated list of the form
  63    "NN;MM;KK;...", where each number is a value of the SGR parameter,
  64    into the corresponding Windows console text attribute.
  65
  66    This function supports a subset of the SGR rendition aspects that
  67    the Windows console can display.  */
  68 static int
  69 w32_sgr2attr (const char *sgr_seq)
  70 {
  71   const char *s, *p;
  72   int code, fg = norm_attr & 15, bg = norm_attr & (15 << 4);
  73   int bright = 0, inverse = 0;
  74   static const int fg_color[] = {
  75     0,                  /* black */
  76     FOREGROUND_RED,     /* red */
  77     FOREGROUND_GREEN,   /* green */
  78     FOREGROUND_GREEN | FOREGROUND_RED, /* yellow */
  79     FOREGROUND_BLUE,                   /* blue */
  80     FOREGROUND_BLUE | FOREGROUND_RED,  /* magenta */
  81     FOREGROUND_BLUE | FOREGROUND_GREEN, /* cyan */
  82     FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE /* gray */
  83   };
  84   static const int bg_color[] = {
  85     0,                  /* black */
  86     BACKGROUND_RED,     /* red */
  87     BACKGROUND_GREEN,   /* green */
  88     BACKGROUND_GREEN | BACKGROUND_RED, /* yellow */
  89     BACKGROUND_BLUE,                   /* blue */
  90     BACKGROUND_BLUE | BACKGROUND_RED,  /* magenta */
  91     BACKGROUND_BLUE | BACKGROUND_GREEN, /* cyan */
  92     BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE /* gray */
  93   };
  94
  95   for (s = p = sgr_seq; *s; p++)
  96     {
  97       if (*p == ';' || *p == '\0')
  98         {
  99           code = strtol (s, NULL, 10);
 100           s = p + (*p != '\0');
 101
 102           switch (code)
 103             {
 104             case 0:     /* all attributes off */
 105               fg = norm_attr & 15;
 106               bg = norm_attr & (15 << 4);
 107               bright = 0;
 108               inverse = 0;
 109               break;
 110             case 1:     /* intensity on */
 111               bright = 1;
 112               break;
 113             case 7:     /* inverse video */
 114               inverse = 1;
 115               break;
 116             case 22:    /* intensity off */
 117               bright = 0;
 118               break;
 119             case 27:    /* inverse off */
 120               inverse = 0;
 121               break;
 122             case 30: case 31: case 32: case 33: /* foreground color */
 123             case 34: case 35: case 36: case 37:
 124               fg = fg_color[code - 30];
 125               break;
 126             case 39:    /* default foreground */
 127               fg = norm_attr & 15;
 128               break;
 129             case 40: case 41: case 42: case 43: /* background color */
 130             case 44: case 45: case 46: case 47:
 131               bg = bg_color[code - 40];
 132               break;
 133             case 49:    /* default background */
 134               bg = norm_attr & (15 << 4);
 135               break;
 136             default:
 137               break;
 138             }
 139         }
 140     }
 141   if (inverse)
 142     {
 143       int t = fg;
 144       fg = (bg >> 4);
 145       bg = (t << 4);
 146     }
 147   if (bright)
 148     fg |= FOREGROUND_INTENSITY;
 149
 150   return (bg & (15 << 4)) | (fg & 15);
 151 }
 152
 153 /* Start a colorized text attribute on stdout using the SGR_START
 154    format; the attribute is specified by SGR_SEQ.  */
 155 void
 156 print_start_colorize (char const *sgr_start, char const *sgr_seq)
 157 {
 158   /* If stdout is connected to a console, set the console text
 159      attribute directly instead of using SGR_START.  Otherwise, use
 160      SGR_START to emit the SGR escape sequence as on Posix platforms;
 161      this is needed when Grep is invoked as a subprocess of another
 162      program, such as Emacs, which will handle the display of the
 163      matches.  */
 164   if (hstdout != INVALID_HANDLE_VALUE)
 165     {
 166       SHORT attr = w32_sgr2attr (sgr_seq);
 167       SetConsoleTextAttribute (hstdout, attr);
 168     }
 169   else
 170     printf (sgr_start, sgr_seq);
 171 }
 172
 173 /* Clear to the end of the current line with the default attribute.
 174    This is needed for reasons similar to those that require the "EL to
 175    Right after SGR" operation on Posix platforms: if we don't do this,
 176    setting the 'mt', 'ms', or 'mc' capabilities to use a non-default
 177    background color spills that color to the empty space at the end of
 178    the last screen line in a match whose line spans multiple screen
 179    lines.  */
 180 static void
 181 w32_clreol (void)
 182 {
 183   DWORD nchars;
 184   COORD start_pos;
 185   DWORD written;
 186   CONSOLE_SCREEN_BUFFER_INFO csbi;
 187
 188   GetConsoleScreenBufferInfo (hstdout, &csbi);
 189   start_pos = csbi.dwCursorPosition;
 190   nchars = csbi.dwSize.X - start_pos.X;
 191
 192   FillConsoleOutputAttribute (hstdout, norm_attr, nchars, start_pos,
 193                               &written);
 194   FillConsoleOutputCharacter (hstdout, ' ', nchars, start_pos, &written);
 195 }
 196
 197 /* Restore the normal text attribute using the SGR_END string.  */
 198 void
 199 print_end_colorize (char const *sgr_end)
 200 {
 201   if (hstdout != INVALID_HANDLE_VALUE)
 202     {
 203       SetConsoleTextAttribute (hstdout, norm_attr);
 204       w32_clreol ();
 205     }
 206   else
 207     fputs (sgr_end, stdout);
 208 }