1 /*
2 * Copyright (C) 1984-2021 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 */
45 public void
lsystem(cmd,donemsg)46 lsystem(cmd, donemsg)
47 char *cmd;
48 char *donemsg;
49 {
50 int inp;
51 #if HAVE_SHELL
52 char *shell;
53 char *p;
54 #endif
55 IFILE save_ifile;
56 #if MSDOS_COMPILER && MSDOS_COMPILER!=WIN32C
57 char cwd[FILENAME_MAX+1];
58 #endif
59
60 /*
61 * Print the command which is to be executed,
62 * unless the command starts with a "-".
63 */
64 if (cmd[0] == '-')
65 cmd++;
66 else
67 {
68 clear_bot();
69 putstr("!");
70 putstr(cmd);
71 putstr("\n");
72 }
73
74 #if MSDOS_COMPILER
75 #if MSDOS_COMPILER==WIN32C
76 if (*cmd == '\0')
77 cmd = getenv("COMSPEC");
78 #else
79 /*
80 * Working directory is global on MSDOS.
81 * The child might change the working directory, so we
82 * must save and restore CWD across calls to "system",
83 * or else we won't find our file when we return and
84 * try to "reedit_ifile" it.
85 */
86 getcwd(cwd, FILENAME_MAX);
87 #endif
88 #endif
89
90 /*
91 * Close the current input file.
92 */
93 save_ifile = save_curr_ifile();
94 (void) edit_ifile(NULL_IFILE);
95
96 /*
97 * De-initialize the terminal and take out of raw mode.
98 */
99 deinit();
100 flush(); /* Make sure the deinit chars get out */
101 raw_mode(0);
102 #if MSDOS_COMPILER==WIN32C
103 close_getchr();
104 #endif
105
106 /*
107 * Restore signals to their defaults.
108 */
109 init_signals(0);
110
111 #if HAVE_DUP
112 /*
113 * Force standard input to be the user's terminal
114 * (the normal standard input), even if less's standard input
115 * is coming from a pipe.
116 */
117 inp = dup(0);
118 close(0);
119 #if !MSDOS_COMPILER
120 #if OS2
121 /* The __open() system call translates "/dev/tty" to "con". */
122 if (__open(tty_device(), OPEN_READ) < 0)
123 #else
124 if (open(tty_device(), OPEN_READ) < 0)
125 #endif
126 #endif
127 dup(inp);
128 #endif
129
130 /*
131 * Pass the command to the system to be executed.
132 * If we have a SHELL environment variable, use
133 * <$SHELL -c "command"> instead of just <command>.
134 * If the command is empty, just invoke a shell.
135 */
136 #if HAVE_SHELL
137 p = NULL;
138 if ((shell = lgetenv("SHELL")) != NULL && *shell != '\0')
139 {
140 if (*cmd == '\0')
141 p = save(shell);
142 else
143 {
144 char *esccmd = shell_quote(cmd);
145 if (esccmd != NULL)
146 {
147 int len = (int) (strlen(shell) + strlen(esccmd) + 5);
148 p = (char *) ecalloc(len, sizeof(char));
149 SNPRINTF3(p, len, "%s %s %s", shell, shell_coption(), esccmd);
150 free(esccmd);
151 }
152 }
153 }
154 if (p == NULL)
155 {
156 if (*cmd == '\0')
157 p = save("sh");
158 else
159 p = save(cmd);
160 }
161 system(p);
162 free(p);
163 #else
164 #if MSDOS_COMPILER==DJGPPC
165 /*
166 * Make stdin of the child be in cooked mode.
167 */
168 setmode(0, O_TEXT);
169 /*
170 * We don't need to catch signals of the child (it
171 * also makes trouble with some DPMI servers).
172 */
173 __djgpp_exception_toggle();
174 system(cmd);
175 __djgpp_exception_toggle();
176 #else
177 system(cmd);
178 #endif
179 #endif
180
181 #if HAVE_DUP
182 /*
183 * Restore standard input, reset signals, raw mode, etc.
184 */
185 close(0);
186 dup(inp);
187 close(inp);
188 #endif
189
190 #if MSDOS_COMPILER==WIN32C
191 open_getchr();
192 #endif
193 init_signals(1);
194 raw_mode(1);
195 if (donemsg != NULL)
196 {
197 putstr(donemsg);
198 putstr(" (press RETURN)");
199 get_return();
200 putchr('\n');
201 flush();
202 }
203 init();
204 screen_trashed = 1;
205
206 #if MSDOS_COMPILER && MSDOS_COMPILER!=WIN32C
207 /*
208 * Restore the previous directory (possibly
209 * changed by the child program we just ran).
210 */
211 chdir(cwd);
212 #if MSDOS_COMPILER != DJGPPC
213 /*
214 * Some versions of chdir() don't change to the drive
215 * which is part of CWD. (DJGPP does this in chdir.)
216 */
217 if (cwd[1] == ':')
218 {
219 if (cwd[0] >= 'a' && cwd[0] <= 'z')
220 setdisk(cwd[0] - 'a');
221 else if (cwd[0] >= 'A' && cwd[0] <= 'Z')
222 setdisk(cwd[0] - 'A');
223 }
224 #endif
225 #endif
226
227 /*
228 * Reopen the current input file.
229 */
230 reedit_ifile(save_ifile);
231
232 #if defined(SIGWINCH) || defined(SIGWIND)
233 /*
234 * Since we were ignoring window change signals while we executed
235 * the system command, we must assume the window changed.
236 * Warning: this leaves a signal pending (in "sigs"),
237 * so psignals() should be called soon after lsystem().
238 */
239 winch(0);
240 #endif
241 }
242
243 #endif
244
245 #if PIPEC
246
247 /*
248 * Pipe a section of the input file into the given shell command.
249 * The section to be piped is the section "between" the current
250 * position and the position marked by the given letter.
251 *
252 * If the mark is after the current screen, the section between
253 * the top line displayed and the mark is piped.
254 * If the mark is before the current screen, the section between
255 * the mark and the bottom line displayed is piped.
256 * If the mark is on the current screen, or if the mark is ".",
257 * the whole current screen is piped.
258 */
259 public int
pipe_mark(c,cmd)260 pipe_mark(c, cmd)
261 int c;
262 char *cmd;
263 {
264 POSITION mpos, tpos, bpos;
265
266 /*
267 * mpos = the marked position.
268 * tpos = top of screen.
269 * bpos = bottom of screen.
270 */
271 mpos = markpos(c);
272 if (mpos == NULL_POSITION)
273 return (-1);
274 tpos = position(TOP);
275 if (tpos == NULL_POSITION)
276 tpos = ch_zero();
277 bpos = position(BOTTOM);
278
279 if (c == '.')
280 return (pipe_data(cmd, tpos, bpos));
281 else if (mpos <= tpos)
282 return (pipe_data(cmd, mpos, bpos));
283 else if (bpos == NULL_POSITION)
284 return (pipe_data(cmd, tpos, bpos));
285 else
286 return (pipe_data(cmd, tpos, mpos));
287 }
288
289 /*
290 * Create a pipe to the given shell command.
291 * Feed it the file contents between the positions spos and epos.
292 */
293 public int
pipe_data(cmd,spos,epos)294 pipe_data(cmd, spos, epos)
295 char *cmd;
296 POSITION spos;
297 POSITION epos;
298 {
299 FILE *f;
300 int c;
301
302 /*
303 * This is structured much like lsystem().
304 * Since we're running a shell program, we must be careful
305 * to perform the necessary deinitialization before running
306 * the command, and reinitialization after it.
307 */
308 if (ch_seek(spos) != 0)
309 {
310 error("Cannot seek to start position", NULL_PARG);
311 return (-1);
312 }
313
314 if ((f = popen(cmd, "w")) == NULL)
315 {
316 error("Cannot create pipe", NULL_PARG);
317 return (-1);
318 }
319 clear_bot();
320 putstr("!");
321 putstr(cmd);
322 putstr("\n");
323
324 deinit();
325 flush();
326 raw_mode(0);
327 init_signals(0);
328 #if MSDOS_COMPILER==WIN32C
329 close_getchr();
330 #endif
331 #ifdef SIGPIPE
332 LSIGNAL(SIGPIPE, SIG_IGN);
333 #endif
334
335 c = EOI;
336 while (epos == NULL_POSITION || spos++ <= epos)
337 {
338 /*
339 * Read a character from the file and give it to the pipe.
340 */
341 c = ch_forw_get();
342 if (c == EOI)
343 break;
344 if (putc(c, f) == EOF)
345 break;
346 }
347
348 /*
349 * Finish up the last line.
350 */
351 while (c != '\n' && c != EOI )
352 {
353 c = ch_forw_get();
354 if (c == EOI)
355 break;
356 if (putc(c, f) == EOF)
357 break;
358 }
359
360 pclose(f);
361
362 #ifdef SIGPIPE
363 LSIGNAL(SIGPIPE, SIG_DFL);
364 #endif
365 #if MSDOS_COMPILER==WIN32C
366 open_getchr();
367 #endif
368 init_signals(1);
369 raw_mode(1);
370 init();
371 screen_trashed = 1;
372 #if defined(SIGWINCH) || defined(SIGWIND)
373 /* {{ Probably don't need this here. }} */
374 winch(0);
375 #endif
376 return (0);
377 }
378
379 #endif
380