1 /*
2 * Copyright (C) 1984-2023 Mark Nudelman
3 *
4 * You may distribute under the terms of either the GNU General Public
5 * License or the Less License, as specified in the README file.
6 *
7 * For more information, see the README file.
8 */
9
10
11 /*
12 * Routines to execute other programs.
13 * Necessarily very OS dependent.
14 */
15
16 #include "less.h"
17 #include <signal.h>
18 #include "position.h"
19
20 #if MSDOS_COMPILER
21 #include <dos.h>
22 #if MSDOS_COMPILER==WIN32C && defined(MINGW)
23 #include <direct.h>
24 #define setdisk(n) _chdrive((n)+1)
25 #else
26 #ifdef _MSC_VER
27 #include <direct.h>
28 #define setdisk(n) _chdrive((n)+1)
29 #else
30 #include <dir.h>
31 #endif
32 #endif
33 #endif
34
35 extern int screen_trashed;
36 extern IFILE curr_ifile;
37
38
39 #if HAVE_SYSTEM
40
41 /*
42 * Pass the specified command to a shell to be executed.
43 * Like plain "system()", but handles resetting terminal modes, etc.
44 */
lsystem(char * cmd,char * donemsg)45 public void lsystem(char *cmd, char *donemsg)
46 {
47 int inp;
48 #if HAVE_SHELL
49 char *shell;
50 char *p;
51 #endif
52 IFILE save_ifile;
53 #if MSDOS_COMPILER && MSDOS_COMPILER!=WIN32C
54 char cwd[FILENAME_MAX+1];
55 #endif
56
57 /*
58 * Print the command which is to be executed,
59 * unless the command starts with a "-".
60 */
61 if (cmd[0] == '-')
62 cmd++;
63 else
64 {
65 clear_bot();
66 putstr("!");
67 putstr(cmd);
68 putstr("\n");
69 }
70
71 #if MSDOS_COMPILER
72 #if MSDOS_COMPILER==WIN32C
73 if (*cmd == '\0')
74 cmd = getenv("COMSPEC");
75 #else
76 /*
77 * Working directory is global on MSDOS.
78 * The child might change the working directory, so we
79 * must save and restore CWD across calls to "system",
80 * or else we won't find our file when we return and
81 * try to "reedit_ifile" it.
82 */
83 getcwd(cwd, FILENAME_MAX);
84 #endif
85 #endif
86
87 /*
88 * Close the current input file.
89 */
90 save_ifile = save_curr_ifile();
91 (void) edit_ifile(NULL_IFILE);
92
93 /*
94 * De-initialize the terminal and take out of raw mode.
95 */
96 deinit();
97 flush(); /* Make sure the deinit chars get out */
98 raw_mode(0);
99 #if MSDOS_COMPILER==WIN32C
100 close_getchr();
101 #endif
102
103 /*
104 * Restore signals to their defaults.
105 */
106 init_signals(0);
107
108 #if HAVE_DUP
109 /*
110 * Force standard input to be the user's terminal
111 * (the normal standard input), even if less's standard input
112 * is coming from a pipe.
113 */
114 inp = dup(0);
115 close(0);
116 #if !MSDOS_COMPILER
117 if (open_tty() < 0)
118 #endif
119 dup(inp);
120 #endif
121
122 /*
123 * Pass the command to the system to be executed.
124 * If we have a SHELL environment variable, use
125 * <$SHELL -c "command"> instead of just <command>.
126 * If the command is empty, just invoke a shell.
127 */
128 #if HAVE_SHELL
129 p = NULL;
130 if ((shell = lgetenv("SHELL")) != NULL && *shell != '\0')
131 {
132 if (*cmd == '\0')
133 p = save(shell);
134 else
135 {
136 char *esccmd = shell_quote(cmd);
137 if (esccmd != NULL)
138 {
139 int len = (int) (strlen(shell) + strlen(esccmd) + 5);
140 p = (char *) ecalloc(len, sizeof(char));
141 SNPRINTF3(p, len, "%s %s %s", shell, shell_coption(), esccmd);
142 free(esccmd);
143 }
144 }
145 }
146 if (p == NULL)
147 {
148 if (*cmd == '\0')
149 p = save("sh");
150 else
151 p = save(cmd);
152 }
153 system(p);
154 free(p);
155 #else
156 #if MSDOS_COMPILER==DJGPPC
157 /*
158 * Make stdin of the child be in cooked mode.
159 */
160 setmode(0, O_TEXT);
161 /*
162 * We don't need to catch signals of the child (it
163 * also makes trouble with some DPMI servers).
164 */
165 __djgpp_exception_toggle();
166 system(cmd);
167 __djgpp_exception_toggle();
168 #else
169 system(cmd);
170 #endif
171 #endif
172
173 #if HAVE_DUP
174 /*
175 * Restore standard input, reset signals, raw mode, etc.
176 */
177 close(0);
178 dup(inp);
179 close(inp);
180 #endif
181
182 #if MSDOS_COMPILER==WIN32C
183 open_getchr();
184 #endif
185 init_signals(1);
186 raw_mode(1);
187 if (donemsg != NULL)
188 {
189 putstr(donemsg);
190 putstr(" (press RETURN)");
191 get_return();
192 putchr('\n');
193 flush();
194 }
195 init();
196 screen_trashed = 1;
197
198 #if MSDOS_COMPILER && MSDOS_COMPILER!=WIN32C
199 /*
200 * Restore the previous directory (possibly
201 * changed by the child program we just ran).
202 */
203 chdir(cwd);
204 #if MSDOS_COMPILER != DJGPPC
205 /*
206 * Some versions of chdir() don't change to the drive
207 * which is part of CWD. (DJGPP does this in chdir.)
208 */
209 if (cwd[1] == ':')
210 {
211 if (cwd[0] >= 'a' && cwd[0] <= 'z')
212 setdisk(cwd[0] - 'a');
213 else if (cwd[0] >= 'A' && cwd[0] <= 'Z')
214 setdisk(cwd[0] - 'A');
215 }
216 #endif
217 #endif
218
219 /*
220 * Reopen the current input file.
221 */
222 reedit_ifile(save_ifile);
223
224 #if defined(SIGWINCH) || defined(SIGWIND)
225 /*
226 * Since we were ignoring window change signals while we executed
227 * the system command, we must assume the window changed.
228 * Warning: this leaves a signal pending (in "sigs"),
229 * so psignals() should be called soon after lsystem().
230 */
231 winch(0);
232 #endif
233 }
234
235 #endif
236
237 #if PIPEC
238
239 /*
240 * Pipe a section of the input file into the given shell command.
241 * The section to be piped is the section "between" the current
242 * position and the position marked by the given letter.
243 *
244 * If the mark is after the current screen, the section between
245 * the top line displayed and the mark is piped.
246 * If the mark is before the current screen, the section between
247 * the mark and the bottom line displayed is piped.
248 * If the mark is on the current screen, or if the mark is ".",
249 * the whole current screen is piped.
250 */
pipe_mark(int c,char * cmd)251 public int pipe_mark(int c, char *cmd)
252 {
253 POSITION mpos, tpos, bpos;
254
255 /*
256 * mpos = the marked position.
257 * tpos = top of screen.
258 * bpos = bottom of screen.
259 */
260 mpos = markpos(c);
261 if (mpos == NULL_POSITION)
262 return (-1);
263 tpos = position(TOP);
264 if (tpos == NULL_POSITION)
265 tpos = ch_zero();
266 bpos = position(BOTTOM);
267
268 if (c == '.')
269 return (pipe_data(cmd, tpos, bpos));
270 else if (mpos <= tpos)
271 return (pipe_data(cmd, mpos, bpos));
272 else if (bpos == NULL_POSITION)
273 return (pipe_data(cmd, tpos, bpos));
274 else
275 return (pipe_data(cmd, tpos, mpos));
276 }
277
278 /*
279 * Create a pipe to the given shell command.
280 * Feed it the file contents between the positions spos and epos.
281 */
pipe_data(char * cmd,POSITION spos,POSITION epos)282 public int pipe_data(char *cmd, POSITION spos, POSITION epos)
283 {
284 FILE *f;
285 int c;
286
287 /*
288 * This is structured much like lsystem().
289 * Since we're running a shell program, we must be careful
290 * to perform the necessary deinitialization before running
291 * the command, and reinitialization after it.
292 */
293 if (ch_seek(spos) != 0)
294 {
295 error("Cannot seek to start position", NULL_PARG);
296 return (-1);
297 }
298
299 if ((f = popen(cmd, "w")) == NULL)
300 {
301 error("Cannot create pipe", NULL_PARG);
302 return (-1);
303 }
304 clear_bot();
305 putstr("!");
306 putstr(cmd);
307 putstr("\n");
308
309 deinit();
310 flush();
311 raw_mode(0);
312 init_signals(0);
313 #if MSDOS_COMPILER==WIN32C
314 close_getchr();
315 #endif
316 #ifdef SIGPIPE
317 LSIGNAL(SIGPIPE, SIG_IGN);
318 #endif
319
320 c = EOI;
321 while (epos == NULL_POSITION || spos++ <= epos)
322 {
323 /*
324 * Read a character from the file and give it to the pipe.
325 */
326 c = ch_forw_get();
327 if (c == EOI)
328 break;
329 if (putc(c, f) == EOF)
330 break;
331 }
332
333 /*
334 * Finish up the last line.
335 */
336 while (c != '\n' && c != EOI )
337 {
338 c = ch_forw_get();
339 if (c == EOI)
340 break;
341 if (putc(c, f) == EOF)
342 break;
343 }
344
345 pclose(f);
346
347 #ifdef SIGPIPE
348 LSIGNAL(SIGPIPE, SIG_DFL);
349 #endif
350 #if MSDOS_COMPILER==WIN32C
351 open_getchr();
352 #endif
353 init_signals(1);
354 raw_mode(1);
355 init();
356 screen_trashed = 1;
357 #if defined(SIGWINCH) || defined(SIGWIND)
358 /* {{ Probably don't need this here. }} */
359 winch(0);
360 #endif
361 return (0);
362 }
363
364 #endif
365