2 * Copyright (C) 1984-2007 Mark Nudelman
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.
7 * For more information about less, or for information on how to
8 * contact the author, see the README file.
13 * Routines to execute other programs.
14 * Necessarily very OS dependent.
25 #define setdisk(n) _chdrive((n)+1)
31 extern int screen_trashed;
32 extern IFILE curr_ifile;
38 * Pass the specified command to a shell to be executed.
39 * Like plain "system()", but handles resetting terminal modes, etc.
53 char cwd[FILENAME_MAX+1];
57 * Print the command which is to be executed,
58 * unless the command starts with a "-".
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.
78 getcwd(cwd, FILENAME_MAX);
82 * Close the current input file.
84 save_ifile = save_curr_ifile();
85 (void) edit_ifile(NULL_IFILE);
88 * De-initialize the terminal and take out of raw mode.
91 flush(); /* Make sure the deinit chars get out */
93 #if MSDOS_COMPILER==WIN32C
98 * Restore signals to their defaults.
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.
111 /* The __open() system call translates "/dev/tty" to "con". */
112 if (__open("/dev/tty", OPEN_READ) < 0)
114 if (open("/dev/tty", OPEN_READ) < 0)
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.
127 if ((shell = lgetenv("SHELL")) != NULL && *shell != '\0')
133 char *esccmd = shell_quote(cmd);
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);
153 #if MSDOS_COMPILER==DJGPPC
155 * Make stdin of the child be in cooked mode.
159 * We don't need to catch signals of the child (it
160 * also makes trouble with some DPMI servers).
162 __djgpp_exception_toggle();
164 __djgpp_exception_toggle();
172 * Restore standard input, reset signals, raw mode, etc.
179 #if MSDOS_COMPILER==WIN32C
187 putstr(" (press RETURN)");
197 * Restore the previous directory (possibly
198 * changed by the child program we just ran).
201 #if MSDOS_COMPILER != DJGPPC
203 * Some versions of chdir() don't change to the drive
204 * which is part of CWD. (DJGPP does this in chdir.)
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');
217 * Reopen the current input file.
219 reedit_ifile(save_ifile);
221 #if defined(SIGWINCH) || defined(SIGWIND)
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().
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.
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.
253 POSITION mpos, tpos, bpos;
256 * mpos = the marked position.
257 * tpos = top of screen.
258 * bpos = bottom of screen.
261 if (mpos == NULL_POSITION)
263 tpos = position(TOP);
264 if (tpos == NULL_POSITION)
266 bpos = position(BOTTOM);
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));
275 return (pipe_data(cmd, tpos, mpos));
279 * Create a pipe to the given shell command.
280 * Feed it the file contents between the positions spos and epos.
283 pipe_data(cmd, spos, epos)
290 extern FILE *popen();
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.
298 if (ch_seek(spos) != 0)
300 error("Cannot seek to start position", NULL_PARG);
304 if ((f = popen(cmd, "w")) == NULL)
306 error("Cannot create pipe", NULL_PARG);
318 #if MSDOS_COMPILER==WIN32C
322 LSIGNAL(SIGPIPE, SIG_IGN);
326 while (epos == NULL_POSITION || spos++ <= epos)
329 * Read a character from the file and give it to the pipe.
334 if (putc(c, f) == EOF)
339 * Finish up the last line.
341 while (c != '\n' && c != EOI )
346 if (putc(c, f) == EOF)
353 LSIGNAL(SIGPIPE, SIG_DFL);
355 #if MSDOS_COMPILER==WIN32C
362 #if defined(SIGWINCH) || defined(SIGWIND)
363 /* {{ Probably don't need this here. }} */