static void trapsigs (void) { int i; #if HAVE_SIGACTION catchaction.sa_flags = SA_RESTART; sigemptyset (&catchaction.sa_mask); for (i = 0; i < NUM_SIGS; i++) sigaddset (&catchaction.sa_mask, sigs[i]); #endif for (i = 0; i < NUM_SIGS; i++) { #if HAVE_SIGACTION sigaction (sigs[i], 0, &initial_action[i]); #else initial_action[i] = signal (sigs[i], SIG_IGN); #endif if (initial_handler (i) != SIG_IGN) signal_handler (sigs[i], catchsig); } #ifdef SIGCHLD /* System V fork+wait does not work if SIGCHLD is ignored. */ signal (SIGCHLD, SIG_DFL); #endif sigs_trapped = true; }
/* Untrap signal S, or all trapped signals if S is zero. */ static void untrapsig (int s) { int i; if (sigs_trapped) for (i = 0; i < NUM_SIGS; i++) if ((! s || sigs[i] == s) && initial_handler (i) != SIG_IGN) #if HAVE_SIGACTION sigaction (sigs[i], &initial_action[i], 0); #else signal (sigs[i], initial_action[i]); #endif }
int main (int argc, char *argv[]) { int opt; char const *prog; exit_failure = EXIT_TROUBLE; initialize_main (&argc, &argv); program_name = argv[0]; setlocale (LC_ALL, ""); bindtextdomain (PACKAGE, LOCALEDIR); textdomain (PACKAGE); c_stack_action (cleanup); prog = getenv ("EDITOR"); if (prog) editor_program = prog; diffarg (DEFAULT_DIFF_PROGRAM); /* parse command line args */ while ((opt = getopt_long (argc, argv, "abBdEHiI:lo:stvw:W", longopts, 0)) != -1) { switch (opt) { case 'a': diffarg ("-a"); break; case 'b': diffarg ("-b"); break; case 'B': diffarg ("-B"); break; case 'd': diffarg ("-d"); break; case 'E': diffarg ("-E"); break; case 'H': diffarg ("-H"); break; case 'i': diffarg ("-i"); break; case 'I': diffarg ("-I"); diffarg (optarg); break; case 'l': diffarg ("--left-column"); break; case 'o': output = optarg; break; case 's': suppress_common_lines = true; break; case 't': diffarg ("-t"); break; case 'v': version_etc (stdout, "sdiff", PACKAGE_NAME, PACKAGE_VERSION, "Thomas Lord", (char *) 0); check_stdout (); return EXIT_SUCCESS; case 'w': diffarg ("-W"); diffarg (optarg); break; case 'W': diffarg ("-w"); break; case DIFF_PROGRAM_OPTION: diffargv[0] = optarg; break; case HELP_OPTION: usage (); check_stdout (); return EXIT_SUCCESS; case STRIP_TRAILING_CR_OPTION: diffarg ("--strip-trailing-cr"); break; case TABSIZE_OPTION: diffarg ("--tabsize"); diffarg (optarg); break; default: try_help (0, 0); } } if (argc - optind != 2) { if (argc - optind < 2) try_help ("missing operand after `%s'", argv[argc - 1]); else try_help ("extra operand `%s'", argv[optind + 2]); } if (! output) { /* easy case: diff does everything for us */ if (suppress_common_lines) diffarg ("--suppress-common-lines"); diffarg ("-y"); diffarg ("--"); diffarg (argv[optind]); diffarg (argv[optind + 1]); diffarg (0); execvp (diffargv[0], (char **) diffargv); perror_fatal (diffargv[0]); } else { char const *lname, *rname; FILE *left, *right, *out, *diffout; bool interact_ok; struct line_filter lfilt; struct line_filter rfilt; struct line_filter diff_filt; bool leftdir = diraccess (argv[optind]); bool rightdir = diraccess (argv[optind + 1]); if (leftdir & rightdir) fatal ("both files to be compared are directories"); lname = expand_name (argv[optind], leftdir, argv[optind + 1]); left = ck_fopen (lname, "r"); rname = expand_name (argv[optind + 1], rightdir, argv[optind]); right = ck_fopen (rname, "r"); out = ck_fopen (output, "w"); diffarg ("--sdiff-merge-assist"); diffarg ("--"); diffarg (argv[optind]); diffarg (argv[optind + 1]); diffarg (0); trapsigs (); #if ! (HAVE_WORKING_FORK || HAVE_WORKING_VFORK) { size_t cmdsize = 1; char *p, *command; int i; for (i = 0; diffargv[i]; i++) cmdsize += quote_system_arg (0, diffargv[i]) + 1; command = p = xmalloc (cmdsize); for (i = 0; diffargv[i]; i++) { p += quote_system_arg (p, diffargv[i]); *p++ = ' '; } p[-1] = 0; errno = 0; diffout = popen (command, "r"); if (! diffout) perror_fatal (command); free (command); } #else { int diff_fds[2]; # if HAVE_WORKING_VFORK sigset_t procmask; sigset_t blocked; # endif if (pipe (diff_fds) != 0) perror_fatal ("pipe"); # if HAVE_WORKING_VFORK /* Block SIGINT and SIGPIPE. */ sigemptyset (&blocked); sigaddset (&blocked, SIGINT); sigaddset (&blocked, SIGPIPE); sigprocmask (SIG_BLOCK, &blocked, &procmask); # endif diffpid = vfork (); if (diffpid < 0) perror_fatal ("fork"); if (! diffpid) { /* Alter the child's SIGINT and SIGPIPE handlers; this may munge the parent. The child ignores SIGINT in case the user interrupts the editor. The child does not ignore SIGPIPE, even if the parent does. */ if (initial_handler (handler_index_of_SIGINT) != SIG_IGN) signal_handler (SIGINT, SIG_IGN); signal_handler (SIGPIPE, SIG_DFL); # if HAVE_WORKING_VFORK /* Stop blocking SIGINT and SIGPIPE in the child. */ sigprocmask (SIG_SETMASK, &procmask, 0); # endif close (diff_fds[0]); if (diff_fds[1] != STDOUT_FILENO) { dup2 (diff_fds[1], STDOUT_FILENO); close (diff_fds[1]); } execvp (diffargv[0], (char **) diffargv); _exit (errno == ENOENT ? 127 : 126); } # if HAVE_WORKING_VFORK /* Restore the parent's SIGINT and SIGPIPE behavior. */ if (initial_handler (handler_index_of_SIGINT) != SIG_IGN) signal_handler (SIGINT, catchsig); if (initial_handler (handler_index_of_SIGPIPE) != SIG_IGN) signal_handler (SIGPIPE, catchsig); else signal_handler (SIGPIPE, SIG_IGN); /* Stop blocking SIGINT and SIGPIPE in the parent. */ sigprocmask (SIG_SETMASK, &procmask, 0); # endif close (diff_fds[1]); diffout = fdopen (diff_fds[0], "r"); if (! diffout) perror_fatal ("fdopen"); } #endif lf_init (&diff_filt, diffout); lf_init (&lfilt, left); lf_init (&rfilt, right); interact_ok = interact (&diff_filt, &lfilt, lname, &rfilt, rname, out); ck_fclose (left); ck_fclose (right); ck_fclose (out); { int wstatus; int werrno = 0; #if ! (HAVE_WORKING_FORK || HAVE_WORKING_VFORK) wstatus = pclose (diffout); if (wstatus == -1) werrno = errno; #else ck_fclose (diffout); while (waitpid (diffpid, &wstatus, 0) < 0) if (errno == EINTR) checksigs (); else perror_fatal ("waitpid"); diffpid = 0; #endif if (tmpname) { unlink (tmpname); tmpname = 0; } if (! interact_ok) exiterr (); check_child_status (werrno, wstatus, EXIT_FAILURE, diffargv[0]); untrapsig (0); checksigs (); exit (WEXITSTATUS (wstatus)); } } return EXIT_SUCCESS; /* Fool `-Wall'. */ }