source: vendor/diffutils/2.8.1/src/sdiff.c

Last change on this file was 2556, checked in by bird, 19 years ago

diffutils 2.8.1
File size: 26.0 KB
Line 
1/* sdiff - side-by-side merge of file differences
2
3 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 2001, 2002 Free
4 Software Foundation, Inc.
5
6 This file is part of GNU DIFF.
7
8 GNU DIFF is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
11 any later version.
12
13 GNU DIFF is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
16 See the GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; see the file COPYING.
20 If not, write to the Free Software Foundation,
21 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
22
23#include "system.h"
24
25#include <c-stack.h>
26#include <dirname.h>
27#include <error.h>
28#include <exitfail.h>
29#include <freesoft.h>
30#include <getopt.h>
31#include <quotesys.h>
32#include <stdio.h>
33#include <xalloc.h>
34
35static char const authorship_msgid[] = N_("Written by Thomas Lord.");
36
37static char const copyright_string[] =
38 "Copyright (C) 2002 Free Software Foundation, Inc.";
39
40extern char const version_string[];
41
42/* Size of chunks read from files which must be parsed into lines. */
43#define SDIFF_BUFSIZE ((size_t) 65536)
44
45char *program_name;
46
47static char const *editor_program = DEFAULT_EDITOR_PROGRAM;
48static char const **diffargv;
49
50static char * volatile tmpname;
51static FILE *tmp;
52
53#if HAVE_WORKING_FORK || HAVE_WORKING_VFORK
54static pid_t volatile diffpid;
55#endif
56
57struct line_filter;
58
59static RETSIGTYPE catchsig (int);
60static bool edit (struct line_filter *, char const *, lin, lin, struct line_filter *, char const *, lin, lin, FILE *);
61static bool interact (struct line_filter *, struct line_filter *, char const *, struct line_filter *, char const *, FILE *);
62static void checksigs (void);
63static void diffarg (char const *);
64static void fatal (char const *) __attribute__((noreturn));
65static void perror_fatal (char const *) __attribute__((noreturn));
66static void trapsigs (void);
67static void untrapsig (int);
68
69#define NUM_SIGS (sizeof sigs / sizeof *sigs)
70static int const sigs[] = {
71#ifdef SIGHUP
72 SIGHUP,
73#endif
74#ifdef SIGQUIT
75 SIGQUIT,
76#endif
77#ifdef SIGTERM
78 SIGTERM,
79#endif
80#ifdef SIGXCPU
81 SIGXCPU,
82#endif
83#ifdef SIGXFSZ
84 SIGXFSZ,
85#endif
86 SIGINT,
87 SIGPIPE
88};
89#define handler_index_of_SIGINT (NUM_SIGS - 2)
90#define handler_index_of_SIGPIPE (NUM_SIGS - 1)
91
92#if HAVE_SIGACTION
93 /* Prefer `sigaction' if available, since `signal' can lose signals. */
94 static struct sigaction initial_action[NUM_SIGS];
95# define initial_handler(i) (initial_action[i].sa_handler)
96 static void signal_handler (int, RETSIGTYPE (*) (int));
97#else
98 static RETSIGTYPE (*initial_action[NUM_SIGS]) ();
99# define initial_handler(i) (initial_action[i])
100# define signal_handler(sig, handler) signal (sig, handler)
101#endif
102
103#if ! HAVE_SIGPROCMASK
104# define sigset_t int
105# define sigemptyset(s) (*(s) = 0)
106# ifndef sigmask
107# define sigmask(sig) (1 << ((sig) - 1))
108# endif
109# define sigaddset(s, sig) (*(s) |= sigmask (sig))
110# ifndef SIG_BLOCK
111# define SIG_BLOCK 0
112# endif
113# ifndef SIG_SETMASK
114# define SIG_SETMASK (! SIG_BLOCK)
115# endif
116# define sigprocmask(how, n, o) \
117 ((how) == SIG_BLOCK ? *(o) = sigblock (*(n)) : sigsetmask (*(n)))
118#endif
119
120static bool diraccess (char const *);
121static int temporary_file (void);
122
123/* Options: */
124
125/* Name of output file if -o specified. */
126static char const *output;
127
128/* Do not print common lines. */
129static bool suppress_common_lines;
130
131/* Value for the long option that does not have single-letter equivalents. */
132enum
133{
134 DIFF_PROGRAM_OPTION = CHAR_MAX + 1,
135 HELP_OPTION,
136 STRIP_TRAILING_CR_OPTION
137};
138
139static struct option const longopts[] =
140{
141 {"diff-program", 1, 0, DIFF_PROGRAM_OPTION},
142 {"expand-tabs", 0, 0, 't'},
143 {"help", 0, 0, HELP_OPTION},
144 {"ignore-all-space", 0, 0, 'W'}, /* swap W and w for historical reasons */
145 {"ignore-blank-lines", 0, 0, 'B'},
146 {"ignore-case", 0, 0, 'i'},
147 {"ignore-matching-lines", 1, 0, 'I'},
148 {"ignore-space-change", 0, 0, 'b'},
149 {"ignore-tab-expansion", 0, 0, 'E'},
150 {"left-column", 0, 0, 'l'},
151 {"minimal", 0, 0, 'd'},
152 {"output", 1, 0, 'o'},
153 {"speed-large-files", 0, 0, 'H'},
154 {"strip-trailing-cr", 0, 0, STRIP_TRAILING_CR_OPTION},
155 {"suppress-common-lines", 0, 0, 's'},
156 {"text", 0, 0, 'a'},
157 {"version", 0, 0, 'v'},
158 {"width", 1, 0, 'w'},
159 {0, 0, 0, 0}
160};
161
162static void try_help (char const *, char const *) __attribute__((noreturn));
163static void
164try_help (char const *reason_msgid, char const *operand)
165{
166 if (reason_msgid)
167 error (0, 0, _(reason_msgid), operand);
168 error (EXIT_TROUBLE, 0, _("Try `%s --help' for more information."),
169 program_name);
170 abort ();
171}
172
173static void
174check_stdout (void)
175{
176 if (ferror (stdout))
177 fatal ("write failed");
178 else if (fclose (stdout) != 0)
179 perror_fatal (_("standard output"));
180}
181
182static char const * const option_help_msgid[] = {
183 N_("-o FILE --output=FILE Operate interactively, sending output to FILE."),
184 "",
185 N_("-i --ignore-case Consider upper- and lower-case to be the same."),
186 N_("-E --ignore-tab-expansion Ignore changes due to tab expansion."),
187 N_("-b --ignore-space-change Ignore changes in the amount of white space."),
188 N_("-W --ignore-all-space Ignore all white space."),
189 N_("-B --ignore-blank-lines Ignore changes whose lines are all blank."),
190 N_("-I RE --ignore-matching-lines=RE Ignore changes whose lines all match RE."),
191 N_("--strip-trailing-cr Strip trailing carriage return on input."),
192 N_("-a --text Treat all files as text."),
193 "",
194 N_("-w NUM --width=NUM Output at most NUM (default 130) columns per line."),
195 N_("-l --left-column Output only the left column of common lines."),
196 N_("-s --suppress-common-lines Do not output common lines."),
197 "",
198 N_("-t --expand-tabs Expand tabs to spaces in output."),
199 "",
200 N_("-d --minimal Try hard to find a smaller set of changes."),
201 N_("-H --speed-large-files Assume large files and many scattered small changes."),
202 N_("--diff-program=PROGRAM Use PROGRAM to compare files."),
203 "",
204 N_("-v --version Output version info."),
205 N_("--help Output this help."),
206 0
207};
208
209static void
210usage (void)
211{
212 char const * const *p;
213
214 printf (_("Usage: %s [OPTION]... FILE1 FILE2\n"), program_name);
215 printf ("%s\n\n", _("Side-by-side merge of file differences."));
216 for (p = option_help_msgid; *p; p++)
217 if (**p)
218 printf (" %s\n", _(*p));
219 else
220 putchar ('\n');
221 printf ("\n%s\n\n%s\n",
222 _("If a FILE is `-', read standard input."),
223 _("Report bugs to <bug-gnu-utils@gnu.org>."));
224}
225
226static void
227cleanup (void)
228{
229#if HAVE_WORKING_FORK || HAVE_WORKING_VFORK
230 if (0 < diffpid)
231 kill (diffpid, SIGPIPE);
232#endif
233 if (tmpname)
234 unlink (tmpname);
235}
236
237static void exiterr (void) __attribute__((noreturn));
238static void
239exiterr (void)
240{
241 cleanup ();
242 untrapsig (0);
243 checksigs ();
244 exit (EXIT_TROUBLE);
245}
246
247static void
248fatal (char const *msgid)
249{
250 error (0, 0, "%s", _(msgid));
251 exiterr ();
252}
253
254static void
255perror_fatal (char const *msg)
256{
257 int e = errno;
258 checksigs ();
259 error (0, e, "%s", msg);
260 exiterr ();
261}
262
263static void
264ck_editor_status (int errnum, int status)
265{
266 if (errnum | status)
267 {
268 char const *failure_msgid = N_("subsidiary program `%s' failed");
269 if (! errnum && WIFEXITED (status))
270 switch (WEXITSTATUS (status))
271 {
272 case 126:
273 failure_msgid = N_("subsidiary program `%s' not executable");
274 break;
275 case 127:
276 failure_msgid = N_("subsidiary program `%s' not found");
277 break;
278 }
279 error (0, errnum, _(failure_msgid), editor_program);
280 exiterr ();
281 }
282}
283
284static FILE *
285ck_fopen (char const *fname, char const *type)
286{
287 FILE *r = fopen (fname, type);
288 if (! r)
289 perror_fatal (fname);
290 return r;
291}
292
293static void
294ck_fclose (FILE *f)
295{
296 if (fclose (f))
297 perror_fatal ("fclose");
298}
299
300static size_t
301ck_fread (char *buf, size_t size, FILE *f)
302{
303 size_t r = fread (buf, sizeof (char), size, f);
304 if (r == 0 && ferror (f))
305 perror_fatal (_("read failed"));
306 return r;
307}
308
309static void
310ck_fwrite (char const *buf, size_t size, FILE *f)
311{
312 if (fwrite (buf, sizeof (char), size, f) != size)
313 perror_fatal (_("write failed"));
314}
315
316static void
317ck_fflush (FILE *f)
318{
319 if (fflush (f) != 0)
320 perror_fatal (_("write failed"));
321}
322
323static char const *
324expand_name (char *name, bool is_dir, char const *other_name)
325{
326 if (strcmp (name, "-") == 0)
327 fatal ("cannot interactively merge standard input");
328 if (! is_dir)
329 return name;
330 else
331 {
332 /* Yield NAME/BASE, where BASE is OTHER_NAME's basename. */
333 char const *base = base_name (other_name);
334 size_t namelen = strlen (name), baselen = strlen (base);
335 bool insert_slash = *base_name (name) && name[namelen - 1] != '/';
336 char *r = xmalloc (namelen + insert_slash + baselen + 1);
337 memcpy (r, name, namelen);
338 r[namelen] = '/';
339 memcpy (r + namelen + insert_slash, base, baselen + 1);
340 return r;
341 }
342}
343
344
345
346
347struct line_filter {
348 FILE *infile;
349 char *bufpos;
350 char *buffer;
351 char *buflim;
352};
353
354static void
355lf_init (struct line_filter *lf, FILE *infile)
356{
357 lf->infile = infile;
358 lf->bufpos = lf->buffer = lf->buflim = xmalloc (SDIFF_BUFSIZE + 1);
359 lf->buflim[0] = '\n';
360}
361
362/* Fill an exhausted line_filter buffer from its INFILE */
363static size_t
364lf_refill (struct line_filter *lf)
365{
366 size_t s = ck_fread (lf->buffer, SDIFF_BUFSIZE, lf->infile);
367 lf->bufpos = lf->buffer;
368 lf->buflim = lf->buffer + s;
369 lf->buflim[0] = '\n';
370 checksigs ();
371 return s;
372}
373
374/* Advance LINES on LF's infile, copying lines to OUTFILE */
375static void
376lf_copy (struct line_filter *lf, lin lines, FILE *outfile)
377{
378 char *start = lf->bufpos;
379
380 while (lines)
381 {
382 lf->bufpos = (char *) memchr (lf->bufpos, '\n', lf->buflim - lf->bufpos);
383 if (! lf->bufpos)
384 {
385 ck_fwrite (start, lf->buflim - start, outfile);
386 if (! lf_refill (lf))
387 return;
388 start = lf->bufpos;
389 }
390 else
391 {
392 --lines;
393 ++lf->bufpos;
394 }
395 }
396
397 ck_fwrite (start, lf->bufpos - start, outfile);
398}
399
400/* Advance LINES on LF's infile without doing output */
401static void
402lf_skip (struct line_filter *lf, lin lines)
403{
404 while (lines)
405 {
406 lf->bufpos = (char *) memchr (lf->bufpos, '\n', lf->buflim - lf->bufpos);
407 if (! lf->bufpos)
408 {
409 if (! lf_refill (lf))
410 break;
411 }
412 else
413 {
414 --lines;
415 ++lf->bufpos;
416 }
417 }
418}
419
420/* Snarf a line into a buffer. Return EOF if EOF, 0 if error, 1 if OK. */
421static int
422lf_snarf (struct line_filter *lf, char *buffer, size_t bufsize)
423{
424 for (;;)
425 {
426 char *start = lf->bufpos;
427 char *next = (char *) memchr (start, '\n', lf->buflim + 1 - start);
428 size_t s = next - start;
429 if (bufsize <= s)
430 return 0;
431 memcpy (buffer, start, s);
432 if (next < lf->buflim)
433 {
434 buffer[s] = 0;
435 lf->bufpos = next + 1;
436 return 1;
437 }
438 if (! lf_refill (lf))
439 return s ? 0 : EOF;
440 buffer += s;
441 bufsize -= s;
442 }
443}
444
445
446
447
448int
449main (int argc, char *argv[])
450{
451 int opt;
452 char const *prog;
453
454 exit_failure = EXIT_TROUBLE;
455 initialize_main (&argc, &argv);
456 program_name = argv[0];
457 setlocale (LC_ALL, "");
458 bindtextdomain (PACKAGE, LOCALEDIR);
459 textdomain (PACKAGE);
460 c_stack_action (c_stack_die);
461
462 prog = getenv ("EDITOR");
463 if (prog)
464 editor_program = prog;
465
466 diffarg (DEFAULT_DIFF_PROGRAM);
467
468 /* parse command line args */
469 while ((opt = getopt_long (argc, argv, "abBdHiI:lo:stvw:W", longopts, 0))
470 != -1)
471 {
472 switch (opt)
473 {
474 case 'a':
475 diffarg ("-a");
476 break;
477
478 case 'b':
479 diffarg ("-b");
480 break;
481
482 case 'B':
483 diffarg ("-B");
484 break;
485
486 case 'd':
487 diffarg ("-d");
488 break;
489
490 case 'E':
491 diffarg ("-E");
492 break;
493
494 case 'H':
495 diffarg ("-H");
496 break;
497
498 case 'i':
499 diffarg ("-i");
500 break;
501
502 case 'I':
503 diffarg ("-I");
504 diffarg (optarg);
505 break;
506
507 case 'l':
508 diffarg ("--left-column");
509 break;
510
511 case 'o':
512 output = optarg;
513 break;
514
515 case 's':
516 suppress_common_lines = 1;
517 break;
518
519 case 't':
520 diffarg ("-t");
521 break;
522
523 case 'v':
524 printf ("sdiff %s\n%s\n\n%s\n\n%s\n",
525 version_string, copyright_string,
526 _(free_software_msgid), _(authorship_msgid));
527 check_stdout ();
528 return EXIT_SUCCESS;
529
530 case 'w':
531 diffarg ("-W");
532 diffarg (optarg);
533 break;
534
535 case 'W':
536 diffarg ("-w");
537 break;
538
539 case DIFF_PROGRAM_OPTION:
540 diffargv[0] = optarg;
541 break;
542
543 case HELP_OPTION:
544 usage ();
545 check_stdout ();
546 return EXIT_SUCCESS;
547
548 case STRIP_TRAILING_CR_OPTION:
549 diffarg ("--strip-trailing-cr");
550 break;
551
552 default:
553 try_help (0, 0);
554 }
555 }
556
557 if (argc - optind != 2)
558 {
559 if (argc - optind < 2)
560 try_help ("missing operand after `%s'", argv[argc - 1]);
561 else
562 try_help ("extra operand `%s'", argv[optind + 2]);
563 }
564
565 if (! output)
566 {
567 /* easy case: diff does everything for us */
568 if (suppress_common_lines)
569 diffarg ("--suppress-common-lines");
570 diffarg ("-y");
571 diffarg ("--");
572 diffarg (argv[optind]);
573 diffarg (argv[optind + 1]);
574 diffarg (0);
575 execvp (diffargv[0], (char **) diffargv);
576 perror_fatal (diffargv[0]);
577 }
578 else
579 {
580 char const *lname, *rname;
581 FILE *left, *right, *out, *diffout;
582 bool interact_ok;
583 struct line_filter lfilt;
584 struct line_filter rfilt;
585 struct line_filter diff_filt;
586 bool leftdir = diraccess (argv[optind]);
587 bool rightdir = diraccess (argv[optind + 1]);
588
589 if (leftdir & rightdir)
590 fatal ("both files to be compared are directories");
591
592 lname = expand_name (argv[optind], leftdir, argv[optind + 1]);
593 left = ck_fopen (lname, "r");
594 rname = expand_name (argv[optind + 1], rightdir, argv[optind]);
595 right = ck_fopen (rname, "r");
596 out = ck_fopen (output, "w");
597
598 diffarg ("--sdiff-merge-assist");
599 diffarg ("--");
600 diffarg (argv[optind]);
601 diffarg (argv[optind + 1]);
602 diffarg (0);
603
604 trapsigs ();
605
606#if ! (HAVE_WORKING_FORK || HAVE_WORKING_VFORK)
607 {
608 size_t cmdsize = 1;
609 char *p, *command;
610 int i;
611
612 for (i = 0; diffargv[i]; i++)
613 cmdsize += quote_system_arg (0, diffargv[i]) + 1;
614 command = p = xmalloc (cmdsize);
615 for (i = 0; diffargv[i]; i++)
616 {
617 p += quote_system_arg (p, diffargv[i]);
618 *p++ = ' ';
619 }
620 p[-1] = 0;
621 errno = 0;
622 diffout = popen (command, "r");
623 if (! diffout)
624 perror_fatal (command);
625 free (command);
626 }
627#else
628 {
629 int diff_fds[2];
630# if HAVE_WORKING_VFORK
631 sigset_t procmask;
632 sigset_t blocked;
633# endif
634
635 if (pipe (diff_fds) != 0)
636 perror_fatal ("pipe");
637
638# if HAVE_WORKING_VFORK
639 /* Block SIGINT and SIGPIPE. */
640 sigemptyset (&blocked);
641 sigaddset (&blocked, SIGINT);
642 sigaddset (&blocked, SIGPIPE);
643 sigprocmask (SIG_BLOCK, &blocked, &procmask);
644# endif
645 diffpid = vfork ();
646 if (diffpid < 0)
647 perror_fatal ("fork");
648 if (! diffpid)
649 {
650 /* Alter the child's SIGINT and SIGPIPE handlers;
651 this may munge the parent.
652 The child ignores SIGINT in case the user interrupts the editor.
653 The child does not ignore SIGPIPE, even if the parent does. */
654 if (initial_handler (handler_index_of_SIGINT) != SIG_IGN)
655 signal_handler (SIGINT, SIG_IGN);
656 signal_handler (SIGPIPE, SIG_DFL);
657# if HAVE_WORKING_VFORK
658 /* Stop blocking SIGINT and SIGPIPE in the child. */
659 sigprocmask (SIG_SETMASK, &procmask, 0);
660# endif
661 close (diff_fds[0]);
662 if (diff_fds[1] != STDOUT_FILENO)
663 {
664 dup2 (diff_fds[1], STDOUT_FILENO);
665 close (diff_fds[1]);
666 }
667
668 execvp (diffargv[0], (char **) diffargv);
669 _exit (errno == ENOEXEC ? 126 : 127);
670 }
671
672# if HAVE_WORKING_VFORK
673 /* Restore the parent's SIGINT and SIGPIPE behavior. */
674 if (initial_handler (handler_index_of_SIGINT) != SIG_IGN)
675 signal_handler (SIGINT, catchsig);
676 if (initial_handler (handler_index_of_SIGPIPE) != SIG_IGN)
677 signal_handler (SIGPIPE, catchsig);
678 else
679 signal_handler (SIGPIPE, SIG_IGN);
680
681 /* Stop blocking SIGINT and SIGPIPE in the parent. */
682 sigprocmask (SIG_SETMASK, &procmask, 0);
683# endif
684
685 close (diff_fds[1]);
686 diffout = fdopen (diff_fds[0], "r");
687 if (! diffout)
688 perror_fatal ("fdopen");
689 }
690#endif
691
692 lf_init (&diff_filt, diffout);
693 lf_init (&lfilt, left);
694 lf_init (&rfilt, right);
695
696 interact_ok = interact (&diff_filt, &lfilt, lname, &rfilt, rname, out);
697
698 ck_fclose (left);
699 ck_fclose (right);
700 ck_fclose (out);
701
702 {
703 int wstatus;
704 int werrno = 0;
705
706#if ! (HAVE_WORKING_FORK || HAVE_WORKING_VFORK)
707 wstatus = pclose (diffout);
708 if (wstatus == -1)
709 werrno = errno;
710#else
711 ck_fclose (diffout);
712 while (waitpid (diffpid, &wstatus, 0) < 0)
713 if (errno == EINTR)
714 checksigs ();
715 else
716 perror_fatal ("waitpid");
717 diffpid = 0;
718#endif
719
720 if (tmpname)
721 {
722 unlink (tmpname);
723 tmpname = 0;
724 }
725
726 if (! interact_ok)
727 exiterr ();
728
729 ck_editor_status (werrno, wstatus);
730 untrapsig (0);
731 checksigs ();
732 exit (WEXITSTATUS (wstatus));
733 }
734 }
735 return EXIT_SUCCESS; /* Fool `-Wall'. */
736}
737
738static void
739diffarg (char const *a)
740{
741 static size_t diffargs, diffarglim;
742
743 if (diffargs == diffarglim)
744 {
745 if (! diffarglim)
746 diffarglim = 16;
747 else if (PTRDIFF_MAX / (2 * sizeof *diffargv) <= diffarglim)
748 xalloc_die ();
749 else
750 diffarglim *= 2;
751 diffargv = xrealloc (diffargv, diffarglim * sizeof *diffargv);
752 }
753 diffargv[diffargs++] = a;
754}
755
756
757
758
759
760/* Signal handling */
761
762static bool volatile ignore_SIGINT;
763static int volatile signal_received;
764static bool sigs_trapped;
765
766static RETSIGTYPE
767catchsig (int s)
768{
769#if ! HAVE_SIGACTION
770 signal (s, SIG_IGN);
771#endif
772 if (! (s == SIGINT && ignore_SIGINT))
773 signal_received = s;
774}
775
776#if HAVE_SIGACTION
777static struct sigaction catchaction;
778
779static void
780signal_handler (int sig, RETSIGTYPE (*handler) (int))
781{
782 catchaction.sa_handler = handler;
783 sigaction (sig, &catchaction, 0);
784}
785#endif
786
787static void
788trapsigs (void)
789{
790 int i;
791
792#if HAVE_SIGACTION
793 catchaction.sa_flags = SA_RESTART;
794 sigemptyset (&catchaction.sa_mask);
795 for (i = 0; i < NUM_SIGS; i++)
796 sigaddset (&catchaction.sa_mask, sigs[i]);
797#endif
798
799 for (i = 0; i < NUM_SIGS; i++)
800 {
801#if HAVE_SIGACTION
802 sigaction (sigs[i], 0, &initial_action[i]);
803#else
804 initial_action[i] = signal (sigs[i], SIG_IGN);
805#endif
806 if (initial_handler (i) != SIG_IGN)
807 signal_handler (sigs[i], catchsig);
808 }
809
810#ifdef SIGCHLD
811 /* System V fork+wait does not work if SIGCHLD is ignored. */
812 signal (SIGCHLD, SIG_DFL);
813#endif
814
815 sigs_trapped = 1;
816}
817
818/* Untrap signal S, or all trapped signals if S is zero. */
819static void
820untrapsig (int s)
821{
822 int i;
823
824 if (sigs_trapped)
825 for (i = 0; i < NUM_SIGS; i++)
826 if ((! s || sigs[i] == s) && initial_handler (i) != SIG_IGN)
827#if HAVE_SIGACTION
828 sigaction (sigs[i], &initial_action[i], 0);
829#else
830 signal (sigs[i], initial_action[i]);
831#endif
832}
833
834/* Exit if a signal has been received. */
835static void
836checksigs (void)
837{
838 int s = signal_received;
839 if (s)
840 {
841 cleanup ();
842
843 /* Yield an exit status indicating that a signal was received. */
844 untrapsig (s);
845 kill (getpid (), s);
846
847 /* That didn't work, so exit with error status. */
848 exit (EXIT_TROUBLE);
849 }
850}
851
852
853
854static void
855give_help (void)
856{
857 fprintf (stderr, "%s", _("\
858ed:\tEdit then use both versions, each decorated with a header.\n\
859eb:\tEdit then use both versions.\n\
860el:\tEdit then use the left version.\n\
861er:\tEdit then use the right version.\n\
862e:\tEdit a new version.\n\
863l:\tUse the left version.\n\
864r:\tUse the right version.\n\
865s:\tSilently include common lines.\n\
866v:\tVerbosely include common lines.\n\
867q:\tQuit.\n\
868"));
869}
870
871static int
872skip_white (void)
873{
874 int c;
875 for (;;)
876 {
877 c = getchar ();
878 if (! ISSPACE (c) || c == '\n')
879 break;
880 checksigs ();
881 }
882 if (ferror (stdin))
883 perror_fatal (_("read failed"));
884 return c;
885}
886
887static void
888flush_line (void)
889{
890 int c;
891 while ((c = getchar ()) != '\n' && c != EOF)
892 continue;
893 if (ferror (stdin))
894 perror_fatal (_("read failed"));
895}
896
897
898/* interpret an edit command */
899static bool
900edit (struct line_filter *left, char const *lname, lin lline, lin llen,
901 struct line_filter *right, char const *rname, lin rline, lin rlen,
902 FILE *outfile)
903{
904 for (;;)
905 {
906 int cmd0, cmd1;
907 bool gotcmd = 0;
908
909 cmd1 = 0; /* Pacify `gcc -W'. */
910
911 while (! gotcmd)
912 {
913 if (putchar ('%') != '%')
914 perror_fatal (_("write failed"));
915 ck_fflush (stdout);
916
917 cmd0 = skip_white ();
918 switch (cmd0)
919 {
920 case 'l': case 'r': case 's': case 'v': case 'q':
921 if (skip_white () != '\n')
922 {
923 give_help ();
924 flush_line ();
925 continue;
926 }
927 gotcmd = 1;
928 break;
929
930 case 'e':
931 cmd1 = skip_white ();
932 switch (cmd1)
933 {
934 case 'b': case 'd': case 'l': case 'r':
935 if (skip_white () != '\n')
936 {
937 give_help ();
938 flush_line ();
939 continue;
940 }
941 gotcmd = 1;
942 break;
943 case '\n':
944 gotcmd = 1;
945 break;
946 default:
947 give_help ();
948 flush_line ();
949 continue;
950 }
951 break;
952
953 case EOF:
954 if (feof (stdin))
955 {
956 gotcmd = 1;
957 cmd0 = 'q';
958 break;
959 }
960 /* Fall through. */
961 default:
962 flush_line ();
963 /* Fall through. */
964 case '\n':
965 give_help ();
966 continue;
967 }
968 }
969
970 switch (cmd0)
971 {
972 case 'l':
973 lf_copy (left, llen, outfile);
974 lf_skip (right, rlen);
975 return 1;
976 case 'r':
977 lf_copy (right, rlen, outfile);
978 lf_skip (left, llen);
979 return 1;
980 case 's':
981 suppress_common_lines = 1;
982 break;
983 case 'v':
984 suppress_common_lines = 0;
985 break;
986 case 'q':
987 return 0;
988 case 'e':
989 {
990 int fd;
991
992 if (tmpname)
993 tmp = fopen (tmpname, "w");
994 else
995 {
996 if ((fd = temporary_file ()) < 0)
997 perror_fatal ("mkstemp");
998 tmp = fdopen (fd, "w");
999 }
1000
1001 if (! tmp)
1002 perror_fatal (tmpname);
1003
1004 switch (cmd1)
1005 {
1006 case 'd':
1007 if (llen)
1008 {
1009 if (llen == 1)
1010 fprintf (tmp, "--- %s %ld\n", lname, (long) lline);
1011 else
1012 fprintf (tmp, "--- %s %ld,%ld\n", lname,
1013 (long) lline, (long) (lline + llen - 1));
1014 }
1015 /* Fall through. */
1016 case 'b': case 'l':
1017 lf_copy (left, llen, tmp);
1018 break;
1019
1020 default:
1021 lf_skip (left, llen);
1022 break;
1023 }
1024
1025 switch (cmd1)
1026 {
1027 case 'd':
1028 if (rlen)
1029 {
1030 if (rlen == 1)
1031 fprintf (tmp, "+++ %s %ld\n", rname, (long) rline);
1032 else
1033 fprintf (tmp, "+++ %s %ld,%ld\n", rname,
1034 (long) rline, (long) (rline + rlen - 1));
1035 }
1036 /* Fall through. */
1037 case 'b': case 'r':
1038 lf_copy (right, rlen, tmp);
1039 break;
1040
1041 default:
1042 lf_skip (right, rlen);
1043 break;
1044 }
1045
1046 ck_fclose (tmp);
1047
1048 {
1049 int wstatus;
1050 int werrno = 0;
1051 ignore_SIGINT = 1;
1052 checksigs ();
1053
1054 {
1055#if ! (HAVE_WORKING_FORK || HAVE_WORKING_VFORK)
1056 char *command =
1057 xmalloc (quote_system_arg (0, editor_program)
1058 + 1 + strlen (tmpname) + 1);
1059 sprintf (command + quote_system_arg (command, editor_program),
1060 " %s", tmpname);
1061 wstatus = system (command);
1062 if (wstatus == -1)
1063 werrno = errno;
1064 free (command);
1065#else
1066 pid_t pid;
1067
1068 pid = vfork ();
1069 if (pid == 0)
1070 {
1071 char const *argv[3];
1072 int i = 0;
1073
1074 argv[i++] = editor_program;
1075 argv[i++] = tmpname;
1076 argv[i] = 0;
1077
1078 execvp (editor_program, (char **) argv);
1079 _exit (errno == ENOEXEC ? 126 : 127);
1080 }
1081
1082 if (pid < 0)
1083 perror_fatal ("fork");
1084
1085 while (waitpid (pid, &wstatus, 0) < 0)
1086 if (errno == EINTR)
1087 checksigs ();
1088 else
1089 perror_fatal ("waitpid");
1090#endif
1091 }
1092
1093 ignore_SIGINT = 0;
1094 ck_editor_status (werrno, wstatus);
1095 }
1096
1097 {
1098 char buf[SDIFF_BUFSIZE];
1099 size_t size;
1100 tmp = ck_fopen (tmpname, "r");
1101 while ((size = ck_fread (buf, SDIFF_BUFSIZE, tmp)) != 0)
1102 {
1103 checksigs ();
1104 ck_fwrite (buf, size, outfile);
1105 }
1106 ck_fclose (tmp);
1107 }
1108 return 1;
1109 }
1110 default:
1111 give_help ();
1112 break;
1113 }
1114 }
1115}
1116
1117
1118
1119
1120/* Alternately reveal bursts of diff output and handle user commands. */
1121static bool
1122interact (struct line_filter *diff,
1123 struct line_filter *left, char const *lname,
1124 struct line_filter *right, char const *rname,
1125 FILE *outfile)
1126{
1127 lin lline = 1, rline = 1;
1128
1129 for (;;)
1130 {
1131 char diff_help[256];
1132 int snarfed = lf_snarf (diff, diff_help, sizeof diff_help);
1133
1134 if (snarfed <= 0)
1135 return snarfed != 0;
1136
1137 checksigs ();
1138
1139 if (diff_help[0] == ' ')
1140 puts (diff_help + 1);
1141 else
1142 {
1143 char *numend;
1144 uintmax_t val;
1145 lin llen, rlen, lenmax;
1146 errno = 0;
1147 llen = val = strtoumax (diff_help + 1, &numend, 10);
1148 if (llen < 0 || llen != val || errno || *numend != ',')
1149 fatal (diff_help);
1150 rlen = val = strtoumax (numend + 1, &numend, 10);
1151 if (rlen < 0 || rlen != val || errno || *numend)
1152 fatal (diff_help);
1153
1154 lenmax = MAX (llen, rlen);
1155
1156 switch (diff_help[0])
1157 {
1158 case 'i':
1159 if (suppress_common_lines)
1160 lf_skip (diff, lenmax);
1161 else
1162 lf_copy (diff, lenmax, stdout);
1163
1164 lf_copy (left, llen, outfile);
1165 lf_skip (right, rlen);
1166 break;
1167
1168 case 'c':
1169 lf_copy (diff, lenmax, stdout);
1170 if (! edit (left, lname, lline, llen,
1171 right, rname, rline, rlen,
1172 outfile))
1173 return 0;
1174 break;
1175
1176 default:
1177 fatal (diff_help);
1178 }
1179
1180 lline += llen;
1181 rline += rlen;
1182 }
1183 }
1184}
1185
1186/* Return nonzero if DIR is an existing directory. */
1187static bool
1188diraccess (char const *dir)
1189{
1190 struct stat buf;
1191 return stat (dir, &buf) == 0 && S_ISDIR (buf.st_mode);
1192}
1193
1194#ifndef P_tmpdir
1195# define P_tmpdir "/tmp"
1196#endif
1197#ifndef TMPDIR_ENV
1198# define TMPDIR_ENV "TMPDIR"
1199#endif
1200
1201/* Open a temporary file and return its file descriptor. Put into
1202 tmpname the address of a newly allocated buffer that holds the
1203 file's name. Use the prefix "sdiff". */
1204static int
1205temporary_file (void)
1206{
1207 char const *tmpdir = getenv (TMPDIR_ENV);
1208 char const *dir = tmpdir ? tmpdir : P_tmpdir;
1209 char *buf = xmalloc (strlen (dir) + 1 + 5 + 6 + 1);
1210 int fd;
1211 int e;
1212 sigset_t procmask;
1213 sigset_t blocked;
1214 sprintf (buf, "%s/sdiffXXXXXX", dir);
1215 sigemptyset (&blocked);
1216 sigaddset (&blocked, SIGINT);
1217 sigprocmask (SIG_BLOCK, &blocked, &procmask);
1218 fd = mkstemp (buf);
1219 e = errno;
1220 if (0 <= fd)
1221 tmpname = buf;
1222 sigprocmask (SIG_SETMASK, &procmask, 0);
1223 errno = e;
1224 return fd;
1225}
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