xref: /freebsd/contrib/less/lsystem.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
1 /*
2  * Copyright (C) 1984-2007  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 about less, or for information on how to
8  * contact the author, see the README file.
9  */
10 
11 
12 /*
13  * Routines to execute other programs.
14  * Necessarily very OS dependent.
15  */
16 
17 #include "less.h"
18 #include <signal.h>
19 #include "position.h"
20 
21 #if MSDOS_COMPILER
22 #include <dos.h>
23 #ifdef _MSC_VER
24 #include <direct.h>
25 #define setdisk(n) _chdrive((n)+1)
26 #else
27 #include <dir.h>
28 #endif
29 #endif
30 
31 extern int screen_trashed;
32 extern IFILE curr_ifile;
33 
34 
35 #if HAVE_SYSTEM
36 
37 /*
38  * Pass the specified command to a shell to be executed.
39  * Like plain "system()", but handles resetting terminal modes, etc.
40  */
41 	public void
42 lsystem(cmd, donemsg)
43 	char *cmd;
44 	char *donemsg;
45 {
46 	register int inp;
47 #if HAVE_SHELL
48 	register char *shell;
49 	register char *p;
50 #endif
51 	IFILE save_ifile;
52 #if MSDOS_COMPILER
53 	char cwd[FILENAME_MAX+1];
54 #endif
55 
56 	/*
57 	 * Print the command which is to be executed,
58 	 * unless the command starts with a "-".
59 	 */
60 	if (cmd[0] == '-')
61 		cmd++;
62 	else
63 	{
64 		clear_bot();
65 		putstr("!");
66 		putstr(cmd);
67 		putstr("\n");
68 	}
69 
70 #if MSDOS_COMPILER
71 	/*
72 	 * Working directory is global on MSDOS.
73 	 * The child might change the working directory, so we
74 	 * must save and restore CWD across calls to "system",
75 	 * or else we won't find our file when we return and
76 	 * try to "reedit_ifile" it.
77 	 */
78 	getcwd(cwd, FILENAME_MAX);
79 #endif
80 
81 	/*
82 	 * Close the current input file.
83 	 */
84 	save_ifile = save_curr_ifile();
85 	(void) edit_ifile(NULL_IFILE);
86 
87 	/*
88 	 * De-initialize the terminal and take out of raw mode.
89 	 */
90 	deinit();
91 	flush();	/* Make sure the deinit chars get out */
92 	raw_mode(0);
93 #if MSDOS_COMPILER==WIN32C
94 	close_getchr();
95 #endif
96 
97 	/*
98 	 * Restore signals to their defaults.
99 	 */
100 	init_signals(0);
101 
102 #if HAVE_DUP
103 	/*
104 	 * Force standard input to be the user's terminal
105 	 * (the normal standard input), even if less's standard input
106 	 * is coming from a pipe.
107 	 */
108 	inp = dup(0);
109 	close(0);
110 #if OS2
111 	/* The __open() system call translates "/dev/tty" to "con". */
112 	if (__open("/dev/tty", OPEN_READ) < 0)
113 #else
114 	if (open("/dev/tty", OPEN_READ) < 0)
115 #endif
116 		dup(inp);
117 #endif
118 
119 	/*
120 	 * Pass the command to the system to be executed.
121 	 * If we have a SHELL environment variable, use
122 	 * <$SHELL -c "command"> instead of just <command>.
123 	 * If the command is empty, just invoke a shell.
124 	 */
125 #if HAVE_SHELL
126 	p = NULL;
127 	if ((shell = lgetenv("SHELL")) != NULL && *shell != '\0')
128 	{
129 		if (*cmd == '\0')
130 			p = save(shell);
131 		else
132 		{
133 			char *esccmd = shell_quote(cmd);
134 			if (esccmd != NULL)
135 			{
136 				int len = strlen(shell) + strlen(esccmd) + 5;
137 				p = (char *) ecalloc(len, sizeof(char));
138 				SNPRINTF3(p, len, "%s %s %s", shell, shell_coption(), esccmd);
139 				free(esccmd);
140 			}
141 		}
142 	}
143 	if (p == NULL)
144 	{
145 		if (*cmd == '\0')
146 			p = save("sh");
147 		else
148 			p = save(cmd);
149 	}
150 	system(p);
151 	free(p);
152 #else
153 #if MSDOS_COMPILER==DJGPPC
154 	/*
155 	 * Make stdin of the child be in cooked mode.
156 	 */
157 	setmode(0, O_TEXT);
158 	/*
159 	 * We don't need to catch signals of the child (it
160 	 * also makes trouble with some DPMI servers).
161 	 */
162 	__djgpp_exception_toggle();
163   	system(cmd);
164 	__djgpp_exception_toggle();
165 #else
166 	system(cmd);
167 #endif
168 #endif
169 
170 #if HAVE_DUP
171 	/*
172 	 * Restore standard input, reset signals, raw mode, etc.
173 	 */
174 	close(0);
175 	dup(inp);
176 	close(inp);
177 #endif
178 
179 #if MSDOS_COMPILER==WIN32C
180 	open_getchr();
181 #endif
182 	init_signals(1);
183 	raw_mode(1);
184 	if (donemsg != NULL)
185 	{
186 		putstr(donemsg);
187 		putstr("  (press RETURN)");
188 		get_return();
189 		putchr('\n');
190 		flush();
191 	}
192 	init();
193 	screen_trashed = 1;
194 
195 #if MSDOS_COMPILER
196 	/*
197 	 * Restore the previous directory (possibly
198 	 * changed by the child program we just ran).
199 	 */
200 	chdir(cwd);
201 #if MSDOS_COMPILER != DJGPPC
202 	/*
203 	 * Some versions of chdir() don't change to the drive
204 	 * which is part of CWD.  (DJGPP does this in chdir.)
205 	 */
206 	if (cwd[1] == ':')
207 	{
208 		if (cwd[0] >= 'a' && cwd[0] <= 'z')
209 			setdisk(cwd[0] - 'a');
210 		else if (cwd[0] >= 'A' && cwd[0] <= 'Z')
211 			setdisk(cwd[0] - 'A');
212 	}
213 #endif
214 #endif
215 
216 	/*
217 	 * Reopen the current input file.
218 	 */
219 	reedit_ifile(save_ifile);
220 
221 #if defined(SIGWINCH) || defined(SIGWIND)
222 	/*
223 	 * Since we were ignoring window change signals while we executed
224 	 * the system command, we must assume the window changed.
225 	 * Warning: this leaves a signal pending (in "sigs"),
226 	 * so psignals() should be called soon after lsystem().
227 	 */
228 	winch(0);
229 #endif
230 }
231 
232 #endif
233 
234 #if PIPEC
235 
236 /*
237  * Pipe a section of the input file into the given shell command.
238  * The section to be piped is the section "between" the current
239  * position and the position marked by the given letter.
240  *
241  * If the mark is after the current screen, the section between
242  * the top line displayed and the mark is piped.
243  * If the mark is before the current screen, the section between
244  * the mark and the bottom line displayed is piped.
245  * If the mark is on the current screen, or if the mark is ".",
246  * the whole current screen is piped.
247  */
248 	public int
249 pipe_mark(c, cmd)
250 	int c;
251 	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  */
282 	public int
283 pipe_data(cmd, spos, epos)
284 	char *cmd;
285 	POSITION spos;
286 	POSITION epos;
287 {
288 	register FILE *f;
289 	register int c;
290 	extern FILE *popen();
291 
292 	/*
293 	 * This is structured much like lsystem().
294 	 * Since we're running a shell program, we must be careful
295 	 * to perform the necessary deinitialization before running
296 	 * the command, and reinitialization after it.
297 	 */
298 	if (ch_seek(spos) != 0)
299 	{
300 		error("Cannot seek to start position", NULL_PARG);
301 		return (-1);
302 	}
303 
304 	if ((f = popen(cmd, "w")) == NULL)
305 	{
306 		error("Cannot create pipe", NULL_PARG);
307 		return (-1);
308 	}
309 	clear_bot();
310 	putstr("!");
311 	putstr(cmd);
312 	putstr("\n");
313 
314 	deinit();
315 	flush();
316 	raw_mode(0);
317 	init_signals(0);
318 #if MSDOS_COMPILER==WIN32C
319 	close_getchr();
320 #endif
321 #ifdef SIGPIPE
322 	LSIGNAL(SIGPIPE, SIG_IGN);
323 #endif
324 
325 	c = EOI;
326 	while (epos == NULL_POSITION || spos++ <= epos)
327 	{
328 		/*
329 		 * Read a character from the file and give it to the pipe.
330 		 */
331 		c = ch_forw_get();
332 		if (c == EOI)
333 			break;
334 		if (putc(c, f) == EOF)
335 			break;
336 	}
337 
338 	/*
339 	 * Finish up the last line.
340 	 */
341  	while (c != '\n' && c != EOI )
342  	{
343  		c = ch_forw_get();
344  		if (c == EOI)
345  			break;
346  		if (putc(c, f) == EOF)
347  			break;
348  	}
349 
350 	pclose(f);
351 
352 #ifdef SIGPIPE
353 	LSIGNAL(SIGPIPE, SIG_DFL);
354 #endif
355 #if MSDOS_COMPILER==WIN32C
356 	open_getchr();
357 #endif
358 	init_signals(1);
359 	raw_mode(1);
360 	init();
361 	screen_trashed = 1;
362 #if defined(SIGWINCH) || defined(SIGWIND)
363 	/* {{ Probably don't need this here. }} */
364 	winch(0);
365 #endif
366 	return (0);
367 }
368 
369 #endif
370