1 /* Output colorization on MS-Windows.
2 Copyright 2011-2023 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 }