/* $NetBSD: xargs.c,v 1.19 2008/07/21 14:19:28 lukem Exp $ */ /*- * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * John B. Roll Jr. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $xMach: xargs.c,v 1.6 2002/02/23 05:27:47 tim Exp $ */ #include #ifndef lint __COPYRIGHT("@(#) Copyright (c) 1990, 1993\ The Regents of the University of California. All rights reserved."); #if 0 static char sccsid[] = "@(#)xargs.c 8.1 (Berkeley) 6/6/93"; __FBSDID("$FreeBSD: src/usr.bin/xargs/xargs.c,v 1.62 2006/01/01 22:59:54 jmallett Exp $"); #endif __RCSID("$NetBSD: xargs.c,v 1.19 2008/07/21 14:19:28 lukem Exp $"); #endif /* not lint */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "pathnames.h" static void parse_input(int, char *[]); static void prerun(int, char *[]); static int prompt(void); static void run(char **); static void usage(void) __dead; void strnsubst(char **, const char *, const char *, size_t); static void waitchildren(const char *, int); static char echo[] = _PATH_ECHO; static char **av, **bxp, **ep, **endxp, **xp; static char *argp, *bbp, *ebp, *inpline, *p, *replstr; static const char *eofstr; static int count, insingle, indouble, oflag, pflag, tflag, Rflag, rval, zflag; static int cnt, Iflag, jfound, Lflag, Sflag, wasquoted, xflag; static int curprocs, maxprocs; static volatile int childerr; extern char **environ; int main(int argc, char *argv[]) { long arg_max; int ch, Jflag, nargs, nflag, nline; size_t linelen; char *endptr; setprogname(argv[0]); inpline = replstr = NULL; ep = environ; eofstr = ""; Jflag = nflag = 0; (void)setlocale(LC_ALL, ""); /* * SUSv3 says of the exec family of functions: * The number of bytes available for the new process' * combined argument and environment lists is {ARG_MAX}. It * is implementation-defined whether null terminators, * pointers, and/or any alignment bytes are included in this * total. * * SUSv3 says of xargs: * ... the combined argument and environment lists ... * shall not exceed {ARG_MAX}-2048. * * To be conservative, we use ARG_MAX - 4K, and we do include * nul terminators and pointers in the calculation. * * Given that the smallest argument is 2 bytes in length, this * means that the number of arguments is limited to: * * (ARG_MAX - 4K - LENGTH(env + utility + arguments)) / 2. * * We arbitrarily limit the number of arguments to 5000. This is * allowed by POSIX.2 as long as the resulting minimum exec line is * at least LINE_MAX. Realloc'ing as necessary is possible, but * probably not worthwhile. */ nargs = 5000; if ((arg_max = sysconf(_SC_ARG_MAX)) == -1) errx(1, "sysconf(_SC_ARG_MAX) failed"); nline = arg_max - 4 * 1024; while (*ep != NULL) { /* 1 byte for each '\0' */ nline -= strlen(*ep++) + 1 + sizeof(*ep); } maxprocs = 1; while ((ch = getopt(argc, argv, "0E:I:J:L:n:oP:pR:S:s:rtx")) != -1) switch (ch) { case 'E': eofstr = optarg; break; case 'I': Jflag = 0; Iflag = 1; Lflag = 1; replstr = optarg; break; case 'J': Iflag = 0; Jflag = 1; replstr = optarg; break; case 'L': Lflag = atoi(optarg); break; case 'n': nflag = 1; if ((nargs = atoi(optarg)) <= 0) errx(1, "illegal argument count"); break; case 'o': oflag = 1; break; case 'P': if ((maxprocs = atoi(optarg)) <= 0) errx(1, "max. processes must be >0"); break; case 'p': pflag = 1; break; case 'R': Rflag = strtol(optarg, &endptr, 10); if (*endptr != '\0') errx(1, "replacements must be a number"); break; case 'r': /* GNU compatibility */ break; case 'S': Sflag = strtoul(optarg, &endptr, 10); if (*endptr != '\0') errx(1, "replsize must be a number"); break; case 's': nline = atoi(optarg); break; case 't': tflag = 1; break; case 'x': xflag = 1; break; case '0': zflag = 1; break; case '?': default: usage(); } argc -= optind; argv += optind; if (!Iflag && Rflag) usage(); if (!Iflag && Sflag) usage(); if (Iflag && !Rflag) Rflag = 5; if (Iflag && !Sflag) Sflag = 255; if (xflag && !nflag) usage(); if (Iflag || Lflag) xflag = 1; if (replstr != NULL && *replstr == '\0') errx(1, "replstr may not be empty"); /* * Allocate pointers for the utility name, the utility arguments, * the maximum arguments to be read from stdin and the trailing * NULL. */ linelen = 1 + argc + nargs + 1; if ((av = bxp = malloc(linelen * sizeof(char **))) == NULL) errx(1, "malloc failed"); /* * Use the user's name for the utility as argv[0], just like the * shell. Echo is the default. Set up pointers for the user's * arguments. */ if (*argv == NULL) cnt = strlen(*bxp++ = echo); else { do { if (Jflag && strcmp(*argv, replstr) == 0) { char **avj; jfound = 1; argv++; for (avj = argv; *avj; avj++) cnt += strlen(*avj) + 1; break; } cnt += strlen(*bxp++ = *argv) + 1; } while (*++argv != NULL); } /* * Set up begin/end/traversing pointers into the array. The -n * count doesn't include the trailing NULL pointer, so the malloc * added in an extra slot. */ endxp = (xp = bxp) + nargs; /* * Allocate buffer space for the arguments read from stdin and the * trailing NULL. Buffer space is defined as the default or specified * space, minus the length of the utility name and arguments. Set up * begin/end/traversing pointers into the array. The -s count does * include the trailing NULL, so the malloc didn't add in an extra * slot. */ nline -= cnt; if (nline <= 0) errx(1, "insufficient space for command"); if ((bbp = malloc((size_t)(nline + 1))) == NULL) errx(1, "malloc failed"); ebp = (argp = p = bbp) + nline - 1; for (;;) parse_input(argc, argv); } static void parse_input(int argc, char *argv[]) { int ch, foundeof; char **avj; foundeof = 0; switch (ch = getchar()) { case EOF: /* No arguments since last exec. */ if (p == bbp) { waitchildren(*argv, 1); exit(rval); } goto arg1; case ' ': case '\t': /* Quotes escape tabs and spaces. */ if (insingle || indouble || zflag) goto addch; goto arg2; case '\0': if (zflag) { /* * Increment 'count', so that nulls will be treated * as end-of-line, as well as end-of-argument. This * is needed so -0 works properly with -I and -L. */ count++; goto arg2; } goto addch; case '\n': if (zflag) goto addch; count++; /* Indicate end-of-line (used by -L) */ /* Quotes do not escape newlines. */ arg1: if (insingle || indouble) errx(1, "unterminated quote"); arg2: foundeof = *eofstr != '\0' && strncmp(argp, eofstr, (size_t)(p - argp)) == 0; /* Do not make empty args unless they are quoted */ if ((argp != p || wasquoted) && !foundeof) { *p++ = '\0'; *xp++ = argp; if (Iflag) { size_t curlen; if (inpline == NULL) curlen = 0; else { /* * If this string is not zero * length, append a space for * separation before the next * argument. */ if ((curlen = strlen(inpline)) != 0) (void)strcat(inpline, " "); } curlen++; /* * Allocate enough to hold what we will * be holding in a second, and to append * a space next time through, if we have * to. */ inpline = realloc(inpline, curlen + 2 + strlen(argp)); if (inpline == NULL) errx(1, "realloc failed"); if (curlen == 1) (void)strcpy(inpline, argp); else (void)strcat(inpline, argp); } } /* * If max'd out on args or buffer, or reached EOF, * run the command. If xflag and max'd out on buffer * but not on args, object. Having reached the limit * of input lines, as specified by -L is the same as * maxing out on arguments. */ if (xp == endxp || p > ebp || ch == EOF || (Lflag <= count && xflag) || foundeof) { if (xflag && xp != endxp && p > ebp) errx(1, "insufficient space for arguments"); if (jfound) { for (avj = argv; *avj; avj++) *xp++ = *avj; } prerun(argc, av); if (ch == EOF || foundeof) { waitchildren(*argv, 1); exit(rval); } p = bbp; xp = bxp; count = 0; } argp = p; wasquoted = 0; break; case '\'': if (indouble || zflag) goto addch; insingle = !insingle; wasquoted = 1; break; case '"': if (insingle || zflag) goto addch; indouble = !indouble; wasquoted = 1; break; case '\\': if (zflag) goto addch; /* Backslash escapes anything, is escaped by quotes. */ if (!insingle && !indouble && (ch = getchar()) == EOF) errx(1, "backslash at EOF"); /* FALLTHROUGH */ default: addch: if (p < ebp) { *p++ = ch; break; } /* If only one argument, not enough buffer space. */ if (bxp == xp) errx(1, "insufficient space for argument"); /* Didn't hit argument limit, so if xflag object. */ if (xflag) errx(1, "insufficient space for arguments"); if (jfound) { for (avj = argv; *avj; avj++) *xp++ = *avj; } prerun(argc, av); xp = bxp; cnt = ebp - argp; (void)memcpy(bbp, argp, (size_t)cnt); p = (argp = bbp) + cnt; *p++ = ch; break; } } /* * Do things necessary before run()'ing, such as -I substitution, * and then call run(). */ static void prerun(int argc, char *argv[]) { char **tmp, **tmp2, **avj; int repls; repls = Rflag; if (argc == 0 || repls == 0) { *xp = NULL; run(argv); return; } avj = argv; /* * Allocate memory to hold the argument list, and * a NULL at the tail. */ tmp = malloc((argc + 1) * sizeof(char**)); if (tmp == NULL) errx(1, "malloc failed"); tmp2 = tmp; /* * Save the first argument and iterate over it, we * cannot do strnsubst() to it. */ if ((*tmp++ = strdup(*avj++)) == NULL) errx(1, "strdup failed"); /* * For each argument to utility, if we have not used up * the number of replacements we are allowed to do, and * if the argument contains at least one occurrence of * replstr, call strnsubst(), else just save the string. * Iterations over elements of avj and tmp are done * where appropriate. */ while (--argc) { *tmp = *avj++; if (repls && strstr(*tmp, replstr) != NULL) { strnsubst(tmp++, replstr, inpline, (size_t)Sflag); if (repls > 0) repls--; } else { if ((*tmp = strdup(*tmp)) == NULL) errx(1, "strdup failed"); tmp++; } } /* * Run it. */ *tmp = NULL; run(tmp2); /* * Walk from the tail to the head, free along the way. */ for (; tmp2 != tmp; tmp--) free(*tmp); /* * Now free the list itself. */ free(tmp2); /* * Free the input line buffer, if we have one. */ if (inpline != NULL) { free(inpline); inpline = NULL; } } static void run(char **argv) { int fd; char **avec; /* * If the user wants to be notified of each command before it is * executed, notify them. If they want the notification to be * followed by a prompt, then prompt them. */ if (tflag || pflag) { (void)fprintf(stderr, "%s", *argv); for (avec = argv + 1; *avec != NULL; ++avec) (void)fprintf(stderr, " %s", *avec); /* * If the user has asked to be prompted, do so. */ if (pflag) /* * If they asked not to exec, return without execution * but if they asked to, go to the execution. If we * could not open their tty, break the switch and drop * back to -t behaviour. */ switch (prompt()) { case 0: return; case 1: goto exec; case 2: break; } (void)fprintf(stderr, "\n"); (void)fflush(stderr); } exec: childerr = 0; switch (vfork()) { case -1: err(1, "vfork"); /*NOTREACHED*/ case 0: if (oflag) { if ((fd = open(_PATH_TTY, O_RDONLY)) == -1) err(1, "can't open /dev/tty"); } else { fd = open(_PATH_DEVNULL, O_RDONLY); } if (fd > STDIN_FILENO) { if (dup2(fd, STDIN_FILENO) != 0) err(1, "can't dup2 to stdin"); (void)close(fd); } (void)execvp(argv[0], argv); childerr = errno; _exit(1); } curprocs++; waitchildren(*argv, 0); } static void waitchildren(const char *name, int waitall) { pid_t pid; int status; while ((pid = waitpid(-1, &status, !waitall && curprocs < maxprocs ? WNOHANG : 0)) > 0) { curprocs--; /* If we couldn't invoke the utility, exit. */ if (childerr != 0) { errno = childerr; err(errno == ENOENT ? 127 : 126, "%s", name); } /* * According to POSIX, we have to exit if the utility exits * with a 255 status, or is interrupted by a signal. xargs * is allowed to return any exit status between 1 and 125 * in these cases, but we'll use 124 and 125, the same * values used by GNU xargs. */ if (WIFEXITED(status)) { if (WEXITSTATUS (status) == 255) { warnx ("%s exited with status 255", name); exit(124); } else if (WEXITSTATUS (status) != 0) { rval = 123; } } else if (WIFSIGNALED (status)) { if (WTERMSIG(status) < NSIG) { warnx("%s terminated by SIG%s", name, sys_signame[WTERMSIG(status)]); } else { warnx("%s terminated by signal %d", name, WTERMSIG(status)); } exit(125); } } if (pid == -1 && errno != ECHILD) err(1, "wait3"); } /* * Prompt the user about running a command. */ static int prompt(void) { regex_t cre; size_t rsize; int match; char *response; FILE *ttyfp; if ((ttyfp = fopen(_PATH_TTY, "r")) == NULL) return (2); /* Indicate that the TTY failed to open. */ (void)fprintf(stderr, "?..."); (void)fflush(stderr); if ((response = fgetln(ttyfp, &rsize)) == NULL || regcomp(&cre, nl_langinfo(YESEXPR), REG_BASIC) != 0) { (void)fclose(ttyfp); return (0); } response[rsize - 1] = '\0'; match = regexec(&cre, response, 0, NULL, 0); (void)fclose(ttyfp); regfree(&cre); return (match == 0); } static void usage(void) { (void)fprintf(stderr, "Usage: %s [-0opt] [-E eofstr] [-I replstr [-R replacements] [-S replsize]]\n" " [-J replstr] [-L number] [-n number [-x]] [-P maxprocs]\n" " [-s size] [utility [argument ...]]\n", getprogname()); exit(1); }