1 /* GNU sdiff - side-by-side merge of file differences
2
3 Copyright (C) 1992-1996, 1998, 2001-2002, 2004, 2006-2007, 2009-2013,
4 2015-2018 Free Software Foundation, Inc.
5
6 This file is part of GNU DIFF.
7
8 This program 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 3 of the License, or
11 (at your option) any later version.
12
13 This program 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. See the
16 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. If not, see <http://www.gnu.org/licenses/>. */
20
21 #include "system.h"
22 #include "paths.h"
23
24 #include <stdio.h>
25 #include <unlocked-io.h>
26
27 #include <c-stack.h>
28 #include <dirname.h>
29 #include "die.h"
30 #include <error.h>
31 #include <exitfail.h>
32 #include <file-type.h>
33 #include <getopt.h>
34 #include <progname.h>
35 #include <system-quote.h>
36 #include <version-etc.h>
37 #include <xalloc.h>
38
39 /* The official name of this program (e.g., no 'g' prefix). */
40 #define PROGRAM_NAME "sdiff"
41
42 #define AUTHORS \
43 proper_name ("Thomas Lord")
44
45 /* Size of chunks read from files which must be parsed into lines. */
46 #define SDIFF_BUFSIZE ((size_t) 65536)
47
48 static char const *editor_program = DEFAULT_EDITOR_PROGRAM;
49 static char const **diffargv;
50
51 static char * volatile tmpname;
52 static FILE *tmp;
53
54 #if HAVE_WORKING_FORK
55 static pid_t volatile diffpid;
56 #endif
57
58 struct line_filter;
59
60 static void catchsig (int);
61 static bool edit (struct line_filter *, char const *, lin, lin, struct line_filter *, char const *, lin, lin, FILE *);
62 static bool interact (struct line_filter *, struct line_filter *, char const *, struct line_filter *, char const *, FILE *);
63 static void checksigs (void);
64 static void diffarg (char const *);
65 static void fatal (char const *) __attribute__((noreturn));
66 static void perror_fatal (char const *) __attribute__((noreturn));
67 static void trapsigs (void);
68 static void untrapsig (int);
69
70 static 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 #ifdef SIGPIPE
87 SIGPIPE,
88 #endif
89 SIGINT
90 };
91 enum
92 {
93 NUM_SIGS = sizeof sigs / sizeof *sigs,
94 handler_index_of_SIGINT = NUM_SIGS - 1
95 };
96
97 #if HAVE_SIGACTION
98 /* Prefer 'sigaction' if available, since 'signal' can lose signals. */
99 static struct sigaction initial_action[NUM_SIGS];
100 # define initial_handler(i) (initial_action[i].sa_handler)
101 static void signal_handler (int, void (*) (int));
102 #else
103 static void (*initial_action[NUM_SIGS]) ();
104 # define initial_handler(i) (initial_action[i])
105 # define signal_handler(sig, handler) signal (sig, handler)
106 #endif
107
108 static bool diraccess (char const *);
109 static int temporary_file (void);
110
111 /* Options: */
112
113 /* Name of output file if -o specified. */
114 static char const *output;
115
116 /* Do not print common lines. */
117 static bool suppress_common_lines;
118
119 /* Value for the long option that does not have single-letter equivalents. */
120 enum
121 {
122 DIFF_PROGRAM_OPTION = CHAR_MAX + 1,
123 HELP_OPTION,
124 STRIP_TRAILING_CR_OPTION,
125 TABSIZE_OPTION
126 };
127
128 static struct option const longopts[] =
129 {
130 {"diff-program", 1, 0, DIFF_PROGRAM_OPTION},
131 {"expand-tabs", 0, 0, 't'},
132 {"help", 0, 0, HELP_OPTION},
133 {"ignore-all-space", 0, 0, 'W'}, /* swap W and w for historical reasons */
134 {"ignore-blank-lines", 0, 0, 'B'},
135 {"ignore-case", 0, 0, 'i'},
136 {"ignore-matching-lines", 1, 0, 'I'},
137 {"ignore-space-change", 0, 0, 'b'},
138 {"ignore-tab-expansion", 0, 0, 'E'},
139 {"ignore-trailing-space", 0, 0, 'Z'},
140 {"left-column", 0, 0, 'l'},
141 {"minimal", 0, 0, 'd'},
142 {"output", 1, 0, 'o'},
143 {"speed-large-files", 0, 0, 'H'},
144 {"strip-trailing-cr", 0, 0, STRIP_TRAILING_CR_OPTION},
145 {"suppress-common-lines", 0, 0, 's'},
146 {"tabsize", 1, 0, TABSIZE_OPTION},
147 {"text", 0, 0, 'a'},
148 {"version", 0, 0, 'v'},
149 {"width", 1, 0, 'w'},
150 {0, 0, 0, 0}
151 };
152
153 static void try_help (char const *, char const *) __attribute__((noreturn));
154 static void
try_help(char const * reason_msgid,char const * operand)155 try_help (char const *reason_msgid, char const *operand)
156 {
157 if (reason_msgid)
158 error (0, 0, _(reason_msgid), operand);
159 die (EXIT_TROUBLE, 0, _("Try '%s --help' for more information."),
160 program_name);
161 }
162
163 static void
check_stdout(void)164 check_stdout (void)
165 {
166 if (ferror (stdout))
167 fatal ("write failed");
168 else if (fclose (stdout) != 0)
169 perror_fatal (_("standard output"));
170 }
171
172 static char const * const option_help_msgid[] = {
173 N_("-o, --output=FILE operate interactively, sending output to FILE"),
174 "",
175 N_("-i, --ignore-case consider upper- and lower-case to be the same"),
176 N_("-E, --ignore-tab-expansion ignore changes due to tab expansion"),
177 N_("-Z, --ignore-trailing-space ignore white space at line end"),
178 N_("-b, --ignore-space-change ignore changes in the amount of white space"),
179 N_("-W, --ignore-all-space ignore all white space"),
180 N_("-B, --ignore-blank-lines ignore changes whose lines are all blank"),
181 N_("-I, --ignore-matching-lines=RE ignore changes all whose lines match RE"),
182 N_(" --strip-trailing-cr strip trailing carriage return on input"),
183 N_("-a, --text treat all files as text"),
184 "",
185 N_("-w, --width=NUM output at most NUM (default 130) print columns"),
186 N_("-l, --left-column output only the left column of common lines"),
187 N_("-s, --suppress-common-lines do not output common lines"),
188 "",
189 N_("-t, --expand-tabs expand tabs to spaces in output"),
190 N_(" --tabsize=NUM tab stops at every NUM (default 8) print columns"),
191 "",
192 N_("-d, --minimal try hard to find a smaller set of changes"),
193 N_("-H, --speed-large-files assume large files, many scattered small changes"),
194 N_(" --diff-program=PROGRAM use PROGRAM to compare files"),
195 "",
196 N_(" --help display this help and exit"),
197 N_("-v, --version output version information and exit"),
198 0
199 };
200
201 static void
usage(void)202 usage (void)
203 {
204 char const * const *p;
205
206 printf (_("Usage: %s [OPTION]... FILE1 FILE2\n"), program_name);
207 printf ("%s\n\n",
208 _("Side-by-side merge of differences between FILE1 and FILE2."));
209
210 fputs (_("\
211 Mandatory arguments to long options are mandatory for short options too.\n\
212 "), stdout);
213 for (p = option_help_msgid; *p; p++)
214 if (**p)
215 printf (" %s\n", _(*p));
216 else
217 putchar ('\n');
218 printf ("\n%s\n%s\n",
219 _("If a FILE is '-', read standard input."),
220 _("Exit status is 0 if inputs are the same, 1 if different, 2 if trouble."));
221 emit_bug_reporting_address ();
222 }
223
224 /* Clean up after a signal or other failure. This function is
225 async-signal-safe. */
226 static void
cleanup(int signo)227 cleanup (int signo __attribute__((unused)))
228 {
229 #if HAVE_WORKING_FORK
230 if (0 < diffpid)
231 kill (diffpid, SIGPIPE);
232 #endif
233 if (tmpname)
234 unlink (tmpname);
235 }
236
237 static void exiterr (void) __attribute__((noreturn));
238 static void
exiterr(void)239 exiterr (void)
240 {
241 cleanup (0);
242 untrapsig (0);
243 checksigs ();
244 exit (EXIT_TROUBLE);
245 }
246
247 static void
fatal(char const * msgid)248 fatal (char const *msgid)
249 {
250 error (0, 0, "%s", _(msgid));
251 exiterr ();
252 }
253
254 static void
perror_fatal(char const * msg)255 perror_fatal (char const *msg)
256 {
257 int e = errno;
258 checksigs ();
259 error (0, e, "%s", msg);
260 exiterr ();
261 }
262
263 static void
check_child_status(int werrno,int wstatus,int max_ok_status,char const * subsidiary_program)264 check_child_status (int werrno, int wstatus, int max_ok_status,
265 char const *subsidiary_program)
266 {
267 int status = (! werrno && WIFEXITED (wstatus)
268 ? WEXITSTATUS (wstatus)
269 : INT_MAX);
270
271 if (max_ok_status < status)
272 {
273 error (0, werrno,
274 _(status == 126
275 ? "subsidiary program '%s' could not be invoked"
276 : status == 127
277 ? "subsidiary program '%s' not found"
278 : status == INT_MAX
279 ? "subsidiary program '%s' failed"
280 : "subsidiary program '%s' failed (exit status %d)"),
281 subsidiary_program, status);
282 exiterr ();
283 }
284 }
285
286 static FILE *
ck_fopen(char const * fname,char const * type)287 ck_fopen (char const *fname, char const *type)
288 {
289 FILE *r = fopen (fname, type);
290 if (! r)
291 perror_fatal (fname);
292 return r;
293 }
294
295 static void
ck_fclose(FILE * f)296 ck_fclose (FILE *f)
297 {
298 if (fclose (f))
299 perror_fatal ("fclose");
300 }
301
302 static size_t
ck_fread(char * buf,size_t size,FILE * f)303 ck_fread (char *buf, size_t size, FILE *f)
304 {
305 size_t r = fread (buf, sizeof (char), size, f);
306 if (r == 0 && ferror (f))
307 perror_fatal (_("read failed"));
308 return r;
309 }
310
311 static void
ck_fwrite(char const * buf,size_t size,FILE * f)312 ck_fwrite (char const *buf, size_t size, FILE *f)
313 {
314 if (fwrite (buf, sizeof (char), size, f) != size)
315 perror_fatal (_("write failed"));
316 }
317
318 static void
ck_fflush(FILE * f)319 ck_fflush (FILE *f)
320 {
321 if (fflush (f) != 0)
322 perror_fatal (_("write failed"));
323 }
324
325 static char const *
expand_name(char * name,bool is_dir,char const * other_name)326 expand_name (char *name, bool is_dir, char const *other_name)
327 {
328 if (STREQ (name, "-"))
329 fatal ("cannot interactively merge standard input");
330 if (! is_dir)
331 return name;
332 else
333 {
334 /* Yield NAME/BASE, where BASE is OTHER_NAME's basename. */
335 char const *base = last_component (other_name);
336 size_t namelen = strlen (name), baselen = base_len (base);
337 bool insert_slash = *last_component (name) && name[namelen - 1] != '/';
338 char *r = xmalloc (namelen + insert_slash + baselen + 1);
339 memcpy (r, name, namelen);
340 r[namelen] = '/';
341 memcpy (r + namelen + insert_slash, base, baselen);
342 r[namelen + insert_slash + baselen] = '\0';
343 return r;
344 }
345 }
346
347 struct line_filter {
348 FILE *infile;
349 char *bufpos;
350 char *buffer;
351 char *buflim;
352 };
353
354 static void
lf_init(struct line_filter * lf,FILE * infile)355 lf_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 */
363 static size_t
lf_refill(struct line_filter * lf)364 lf_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 */
375 static void
lf_copy(struct line_filter * lf,lin lines,FILE * outfile)376 lf_copy (struct line_filter *lf, lin lines, FILE *outfile)
377 {
378 char *start = lf->bufpos;
379
380 while (lines)
381 {
382 lf->bufpos = rawmemchr (lf->bufpos, '\n');
383 if (lf->bufpos == lf->buflim)
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 */
401 static void
lf_skip(struct line_filter * lf,lin lines)402 lf_skip (struct line_filter *lf, lin lines)
403 {
404 while (lines)
405 {
406 lf->bufpos = rawmemchr (lf->bufpos, '\n');
407 if (lf->bufpos == lf->buflim)
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. */
421 static int
lf_snarf(struct line_filter * lf,char * buffer,size_t bufsize)422 lf_snarf (struct line_filter *lf, char *buffer, size_t bufsize)
423 {
424 for (;;)
425 {
426 char *start = lf->bufpos;
427 char *next = rawmemchr (start, '\n');
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 int
main(int argc,char * argv[])446 main (int argc, char *argv[])
447 {
448 int opt;
449 char const *prog;
450
451 exit_failure = EXIT_TROUBLE;
452 initialize_main (&argc, &argv);
453 set_program_name (argv[0]);
454 setlocale (LC_ALL, "");
455 textdomain (PACKAGE);
456 c_stack_action (cleanup);
457
458 prog = getenv ("EDITOR");
459 if (prog)
460 editor_program = prog;
461
462 diffarg (DEFAULT_DIFF_PROGRAM);
463
464 /* parse command line args */
465 while ((opt = getopt_long (argc, argv, "abBdEHiI:lo:stvw:WZ", longopts, 0))
466 != -1)
467 {
468 switch (opt)
469 {
470 case 'a':
471 diffarg ("-a");
472 break;
473
474 case 'b':
475 diffarg ("-b");
476 break;
477
478 case 'B':
479 diffarg ("-B");
480 break;
481
482 case 'd':
483 diffarg ("-d");
484 break;
485
486 case 'E':
487 diffarg ("-E");
488 break;
489
490 case 'H':
491 diffarg ("-H");
492 break;
493
494 case 'i':
495 diffarg ("-i");
496 break;
497
498 case 'I':
499 diffarg ("-I");
500 diffarg (optarg);
501 break;
502
503 case 'l':
504 diffarg ("--left-column");
505 break;
506
507 case 'o':
508 output = optarg;
509 break;
510
511 case 's':
512 suppress_common_lines = true;
513 break;
514
515 case 't':
516 diffarg ("-t");
517 break;
518
519 case 'v':
520 version_etc (stdout, PROGRAM_NAME, PACKAGE_NAME, Version,
521 AUTHORS, (char *) NULL);
522 check_stdout ();
523 return EXIT_SUCCESS;
524
525 case 'w':
526 diffarg ("-W");
527 diffarg (optarg);
528 break;
529
530 case 'W':
531 diffarg ("-w");
532 break;
533
534 case 'Z':
535 diffarg ("-Z");
536 break;
537
538 case DIFF_PROGRAM_OPTION:
539 diffargv[0] = optarg;
540 break;
541
542 case HELP_OPTION:
543 usage ();
544 check_stdout ();
545 return EXIT_SUCCESS;
546
547 case STRIP_TRAILING_CR_OPTION:
548 diffarg ("--strip-trailing-cr");
549 break;
550
551 case TABSIZE_OPTION:
552 diffarg ("--tabsize");
553 diffarg (optarg);
554 break;
555
556 default:
557 try_help (0, 0);
558 }
559 }
560
561 if (argc - optind != 2)
562 {
563 if (argc - optind < 2)
564 try_help ("missing operand after '%s'", argv[argc - 1]);
565 else
566 try_help ("extra operand '%s'", argv[optind + 2]);
567 }
568
569 if (! output)
570 {
571 /* easy case: diff does everything for us */
572 if (suppress_common_lines)
573 diffarg ("--suppress-common-lines");
574 diffarg ("-y");
575 diffarg ("--");
576 diffarg (argv[optind]);
577 diffarg (argv[optind + 1]);
578 diffarg (0);
579 execvp (diffargv[0], (char **) diffargv);
580 perror_fatal (diffargv[0]);
581 }
582 else
583 {
584 char const *lname, *rname;
585 FILE *left, *right, *out, *diffout;
586 bool interact_ok;
587 struct line_filter lfilt;
588 struct line_filter rfilt;
589 struct line_filter diff_filt;
590 bool leftdir = diraccess (argv[optind]);
591 bool rightdir = diraccess (argv[optind + 1]);
592
593 if (leftdir & rightdir)
594 fatal ("both files to be compared are directories");
595
596 lname = expand_name (argv[optind], leftdir, argv[optind + 1]);
597 left = ck_fopen (lname, "r");
598 rname = expand_name (argv[optind + 1], rightdir, argv[optind]);
599 right = ck_fopen (rname, "r");
600 out = ck_fopen (output, "w");
601
602 diffarg ("--sdiff-merge-assist");
603 diffarg ("--");
604 diffarg (argv[optind]);
605 diffarg (argv[optind + 1]);
606 diffarg (0);
607
608 trapsigs ();
609
610 #if ! HAVE_WORKING_FORK
611 {
612 char *command = system_quote_argv (SCI_SYSTEM, (char **) diffargv);
613 errno = 0;
614 diffout = popen (command, "r");
615 if (! diffout)
616 perror_fatal (command);
617 free (command);
618 }
619 #else
620 {
621 int diff_fds[2];
622
623 if (pipe (diff_fds) != 0)
624 perror_fatal ("pipe");
625
626 diffpid = fork ();
627 if (diffpid < 0)
628 perror_fatal ("fork");
629 if (! diffpid)
630 {
631 /* Alter the child's SIGINT and SIGPIPE handlers;
632 this may munge the parent.
633 The child ignores SIGINT in case the user interrupts the editor.
634 The child does not ignore SIGPIPE, even if the parent does. */
635 if (initial_handler (handler_index_of_SIGINT) != SIG_IGN)
636 signal_handler (SIGINT, SIG_IGN);
637 signal_handler (SIGPIPE, SIG_DFL);
638 close (diff_fds[0]);
639 if (diff_fds[1] != STDOUT_FILENO)
640 {
641 dup2 (diff_fds[1], STDOUT_FILENO);
642 close (diff_fds[1]);
643 }
644
645 execvp (diffargv[0], (char **) diffargv);
646 _exit (errno == ENOENT ? 127 : 126);
647 }
648
649 close (diff_fds[1]);
650 diffout = fdopen (diff_fds[0], "r");
651 if (! diffout)
652 perror_fatal ("fdopen");
653 }
654 #endif
655
656 lf_init (&diff_filt, diffout);
657 lf_init (&lfilt, left);
658 lf_init (&rfilt, right);
659
660 interact_ok = interact (&diff_filt, &lfilt, lname, &rfilt, rname, out);
661
662 ck_fclose (left);
663 ck_fclose (right);
664 ck_fclose (out);
665
666 {
667 int wstatus;
668 int werrno = 0;
669
670 #if ! HAVE_WORKING_FORK
671 wstatus = pclose (diffout);
672 if (wstatus == -1)
673 werrno = errno;
674 #else
675 ck_fclose (diffout);
676 while (waitpid (diffpid, &wstatus, 0) < 0)
677 if (errno == EINTR)
678 checksigs ();
679 else
680 perror_fatal ("waitpid");
681 diffpid = 0;
682 #endif
683
684 if (tmpname)
685 {
686 unlink (tmpname);
687 tmpname = 0;
688 }
689
690 if (! interact_ok)
691 exiterr ();
692
693 check_child_status (werrno, wstatus, EXIT_FAILURE, diffargv[0]);
694 untrapsig (0);
695 checksigs ();
696 exit (WEXITSTATUS (wstatus));
697 }
698 }
699 return EXIT_SUCCESS; /* Fool '-Wall'. */
700 }
701
702 static void
diffarg(char const * a)703 diffarg (char const *a)
704 {
705 static size_t diffargs, diffarglim;
706
707 if (diffargs == diffarglim)
708 {
709 if (! diffarglim)
710 diffarglim = 16;
711 else if (PTRDIFF_MAX / (2 * sizeof *diffargv) <= diffarglim)
712 xalloc_die ();
713 else
714 diffarglim *= 2;
715 diffargv = xrealloc (diffargv, diffarglim * sizeof *diffargv);
716 }
717 diffargv[diffargs++] = a;
718 }
719
720 /* Signal handling */
721
722 static bool volatile ignore_SIGINT;
723 static int volatile signal_received;
724 static bool sigs_trapped;
725
726 static void
catchsig(int s)727 catchsig (int s)
728 {
729 #if ! HAVE_SIGACTION
730 signal (s, SIG_IGN);
731 #endif
732 if (! (s == SIGINT && ignore_SIGINT))
733 signal_received = s;
734 }
735
736 #if HAVE_SIGACTION
737 static struct sigaction catchaction;
738
739 static void
signal_handler(int sig,void (* handler)(int))740 signal_handler (int sig, void (*handler) (int))
741 {
742 catchaction.sa_handler = handler;
743 sigaction (sig, &catchaction, 0);
744 }
745 #endif
746
747 static void
trapsigs(void)748 trapsigs (void)
749 {
750 int i;
751
752 #if HAVE_SIGACTION
753 catchaction.sa_flags = SA_RESTART;
754 sigemptyset (&catchaction.sa_mask);
755 for (i = 0; i < NUM_SIGS; i++)
756 sigaddset (&catchaction.sa_mask, sigs[i]);
757 #endif
758
759 for (i = 0; i < NUM_SIGS; i++)
760 {
761 #if HAVE_SIGACTION
762 sigaction (sigs[i], 0, &initial_action[i]);
763 #else
764 initial_action[i] = signal (sigs[i], SIG_IGN);
765 #endif
766 if (initial_handler (i) != SIG_IGN)
767 signal_handler (sigs[i], catchsig);
768 }
769
770 #ifdef SIGCHLD
771 /* System V fork+wait does not work if SIGCHLD is ignored. */
772 signal (SIGCHLD, SIG_DFL);
773 #endif
774
775 sigs_trapped = true;
776 }
777
778 /* Untrap signal S, or all trapped signals if S is zero. */
779 static void
untrapsig(int s)780 untrapsig (int s)
781 {
782 int i;
783
784 if (sigs_trapped)
785 for (i = 0; i < NUM_SIGS; i++)
786 if ((! s || sigs[i] == s) && initial_handler (i) != SIG_IGN)
787 {
788 #if HAVE_SIGACTION
789 sigaction (sigs[i], &initial_action[i], 0);
790 #else
791 signal (sigs[i], initial_action[i]);
792 #endif
793 }
794 }
795
796 /* Exit if a signal has been received. */
797 static void
checksigs(void)798 checksigs (void)
799 {
800 int s = signal_received;
801 if (s)
802 {
803 cleanup (0);
804
805 /* Yield an exit status indicating that a signal was received. */
806 untrapsig (s);
807 raise (s);
808
809 /* That didn't work, so exit with error status. */
810 exit (EXIT_TROUBLE);
811 }
812 }
813
814 static void
give_help(void)815 give_help (void)
816 {
817 fprintf (stderr, "%s", _("\
818 ed:\tEdit then use both versions, each decorated with a header.\n\
819 eb:\tEdit then use both versions.\n\
820 el or e1:\tEdit then use the left version.\n\
821 er or e2:\tEdit then use the right version.\n\
822 e:\tDiscard both versions then edit a new one.\n\
823 l or 1:\tUse the left version.\n\
824 r or 2:\tUse the right version.\n\
825 s:\tSilently include common lines.\n\
826 v:\tVerbosely include common lines.\n\
827 q:\tQuit.\n\
828 "));
829 }
830
831 static int
skip_white(void)832 skip_white (void)
833 {
834 int c;
835 for (;;)
836 {
837 c = getchar ();
838 if (! isspace (c) || c == '\n')
839 break;
840 checksigs ();
841 }
842 if (ferror (stdin))
843 perror_fatal (_("read failed"));
844 return c;
845 }
846
847 static void
flush_line(void)848 flush_line (void)
849 {
850 int c;
851 while ((c = getchar ()) != '\n' && c != EOF)
852 continue;
853 if (ferror (stdin))
854 perror_fatal (_("read failed"));
855 }
856
857
858 /* interpret an edit command */
859 static bool
edit(struct line_filter * left,char const * lname,lin lline,lin llen,struct line_filter * right,char const * rname,lin rline,lin rlen,FILE * outfile)860 edit (struct line_filter *left, char const *lname, lin lline, lin llen,
861 struct line_filter *right, char const *rname, lin rline, lin rlen,
862 FILE *outfile)
863 {
864 for (;;)
865 {
866 int cmd0 IF_LINT (= 0);
867 int cmd1 IF_LINT (= 0);
868 bool gotcmd = false;
869
870 while (! gotcmd)
871 {
872 if (putchar ('%') != '%')
873 perror_fatal (_("write failed"));
874 ck_fflush (stdout);
875
876 cmd0 = skip_white ();
877 switch (cmd0)
878 {
879 case '1': case '2': case 'l': case 'r':
880 case 's': case 'v': case 'q':
881 if (skip_white () != '\n')
882 {
883 give_help ();
884 flush_line ();
885 continue;
886 }
887 gotcmd = true;
888 break;
889
890 case 'e':
891 cmd1 = skip_white ();
892 switch (cmd1)
893 {
894 case '1': case '2': case 'b': case 'd': case 'l': case 'r':
895 if (skip_white () != '\n')
896 {
897 give_help ();
898 flush_line ();
899 continue;
900 }
901 gotcmd = true;
902 break;
903 case '\n':
904 gotcmd = true;
905 break;
906 default:
907 give_help ();
908 flush_line ();
909 continue;
910 }
911 break;
912
913 case EOF:
914 if (feof (stdin))
915 {
916 gotcmd = true;
917 cmd0 = 'q';
918 break;
919 }
920 FALLTHROUGH;
921 default:
922 flush_line ();
923 FALLTHROUGH;
924 case '\n':
925 give_help ();
926 continue;
927 }
928 }
929
930 switch (cmd0)
931 {
932 case '1': case 'l':
933 lf_copy (left, llen, outfile);
934 lf_skip (right, rlen);
935 return true;
936 case '2': case 'r':
937 lf_copy (right, rlen, outfile);
938 lf_skip (left, llen);
939 return true;
940 case 's':
941 suppress_common_lines = true;
942 break;
943 case 'v':
944 suppress_common_lines = false;
945 break;
946 case 'q':
947 return false;
948 case 'e':
949 {
950 int fd;
951
952 if (tmpname)
953 tmp = fopen (tmpname, "w");
954 else
955 {
956 if ((fd = temporary_file ()) < 0)
957 perror_fatal ("mkstemp");
958 tmp = fdopen (fd, "w");
959 }
960
961 if (! tmp)
962 perror_fatal (tmpname);
963
964 switch (cmd1)
965 {
966 case 'd':
967 if (llen)
968 {
969 printint l1 = lline;
970 printint l2 = lline + llen - 1;
971 if (llen == 1)
972 fprintf (tmp, "--- %s %"pI"d\n", lname, l1);
973 else
974 fprintf (tmp, "--- %s %"pI"d,%"pI"d\n", lname, l1, l2);
975 }
976 FALLTHROUGH;
977 case '1': case 'b': case 'l':
978 lf_copy (left, llen, tmp);
979 break;
980
981 default:
982 lf_skip (left, llen);
983 break;
984 }
985
986 switch (cmd1)
987 {
988 case 'd':
989 if (rlen)
990 {
991 printint l1 = rline;
992 printint l2 = rline + rlen - 1;
993 if (rlen == 1)
994 fprintf (tmp, "+++ %s %"pI"d\n", rname, l1);
995 else
996 fprintf (tmp, "+++ %s %"pI"d,%"pI"d\n", rname, l1, l2);
997 }
998 FALLTHROUGH;
999 case '2': case 'b': case 'r':
1000 lf_copy (right, rlen, tmp);
1001 break;
1002
1003 default:
1004 lf_skip (right, rlen);
1005 break;
1006 }
1007
1008 ck_fclose (tmp);
1009
1010 {
1011 int wstatus;
1012 int werrno = 0;
1013 char const *argv[3];
1014
1015 ignore_SIGINT = true;
1016 checksigs ();
1017 argv[0] = editor_program;
1018 argv[1] = tmpname;
1019 argv[2] = 0;
1020
1021 {
1022 #if ! HAVE_WORKING_FORK
1023 char *command = system_quote_argv (SCI_SYSTEM, (char **) argv);
1024 wstatus = system (command);
1025 if (wstatus == -1)
1026 werrno = errno;
1027 free (command);
1028 #else
1029 pid_t pid;
1030
1031 pid = fork ();
1032 if (pid == 0)
1033 {
1034 execvp (editor_program, (char **) argv);
1035 _exit (errno == ENOENT ? 127 : 126);
1036 }
1037
1038 if (pid < 0)
1039 perror_fatal ("fork");
1040
1041 while (waitpid (pid, &wstatus, 0) < 0)
1042 if (errno == EINTR)
1043 checksigs ();
1044 else
1045 perror_fatal ("waitpid");
1046 #endif
1047 }
1048
1049 ignore_SIGINT = false;
1050 check_child_status (werrno, wstatus, EXIT_SUCCESS,
1051 editor_program);
1052 }
1053
1054 {
1055 char buf[SDIFF_BUFSIZE];
1056 size_t size;
1057 tmp = ck_fopen (tmpname, "r");
1058 while ((size = ck_fread (buf, SDIFF_BUFSIZE, tmp)) != 0)
1059 {
1060 checksigs ();
1061 ck_fwrite (buf, size, outfile);
1062 }
1063 ck_fclose (tmp);
1064 }
1065 return true;
1066 }
1067 default:
1068 give_help ();
1069 break;
1070 }
1071 }
1072 }
1073
1074 /* Alternately reveal bursts of diff output and handle user commands. */
1075 static bool
interact(struct line_filter * diff,struct line_filter * left,char const * lname,struct line_filter * right,char const * rname,FILE * outfile)1076 interact (struct line_filter *diff,
1077 struct line_filter *left, char const *lname,
1078 struct line_filter *right, char const *rname,
1079 FILE *outfile)
1080 {
1081 lin lline = 1, rline = 1;
1082
1083 for (;;)
1084 {
1085 char diff_help[256];
1086 int snarfed = lf_snarf (diff, diff_help, sizeof diff_help);
1087
1088 if (snarfed <= 0)
1089 return snarfed != 0;
1090
1091 checksigs ();
1092
1093 if (diff_help[0] == ' ')
1094 puts (diff_help + 1);
1095 else
1096 {
1097 char *numend;
1098 uintmax_t val;
1099 lin llen, rlen, lenmax;
1100 errno = 0;
1101 val = strtoumax (diff_help + 1, &numend, 10);
1102 if (LIN_MAX < val || errno || *numend != ',')
1103 fatal (diff_help);
1104 llen = val;
1105 val = strtoumax (numend + 1, &numend, 10);
1106 if (LIN_MAX < val || errno || *numend)
1107 fatal (diff_help);
1108 rlen = val;
1109
1110 lenmax = MAX (llen, rlen);
1111
1112 switch (diff_help[0])
1113 {
1114 case 'i':
1115 if (suppress_common_lines)
1116 lf_skip (diff, lenmax);
1117 else
1118 lf_copy (diff, lenmax, stdout);
1119
1120 lf_copy (left, llen, outfile);
1121 lf_skip (right, rlen);
1122 break;
1123
1124 case 'c':
1125 lf_copy (diff, lenmax, stdout);
1126 if (! edit (left, lname, lline, llen,
1127 right, rname, rline, rlen,
1128 outfile))
1129 return false;
1130 break;
1131
1132 default:
1133 fatal (diff_help);
1134 }
1135
1136 lline += llen;
1137 rline += rlen;
1138 }
1139 }
1140 }
1141
1142 /* Return true if DIR is an existing directory. */
1143 static bool
diraccess(char const * dir)1144 diraccess (char const *dir)
1145 {
1146 struct stat buf;
1147 return stat (dir, &buf) == 0 && S_ISDIR (buf.st_mode);
1148 }
1149
1150 #ifndef P_tmpdir
1151 # define P_tmpdir "/tmp"
1152 #endif
1153 #ifndef TMPDIR_ENV
1154 # define TMPDIR_ENV "TMPDIR"
1155 #endif
1156
1157 /* Open a temporary file and return its file descriptor. Put into
1158 tmpname the address of a newly allocated buffer that holds the
1159 file's name. Use the prefix "sdiff". */
1160 static int
temporary_file(void)1161 temporary_file (void)
1162 {
1163 char const *tmpdir = getenv (TMPDIR_ENV);
1164 char const *dir = tmpdir ? tmpdir : P_tmpdir;
1165 char *buf = xmalloc (strlen (dir) + 1 + 5 + 6 + 1);
1166 int fd;
1167 sprintf (buf, "%s/sdiffXXXXXX", dir);
1168 fd = mkstemp (buf);
1169 if (0 <= fd)
1170 tmpname = buf;
1171 return fd;
1172 }
1173