diff options
Diffstat (limited to 'usr.bin/xargs/xargs.c')
| -rw-r--r-- | usr.bin/xargs/xargs.c | 652 |
1 files changed, 652 insertions, 0 deletions
diff --git a/usr.bin/xargs/xargs.c b/usr.bin/xargs/xargs.c new file mode 100644 index 0000000..5c89377 --- /dev/null +++ b/usr.bin/xargs/xargs.c @@ -0,0 +1,652 @@ +/* $NetBSD: xargs.c,v 1.20 2010/12/17 11:32:57 plunky 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 <sys/cdefs.h> +#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 1.20 2010/12/17 11:32:57 plunky Exp $"); +#endif /* not lint */ + +#include <sys/param.h> +#include <sys/wait.h> + +#include <err.h> +#include <errno.h> +#include <fcntl.h> +#include <langinfo.h> +#include <locale.h> +#include <paths.h> +#include <regex.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <signal.h> +#include <unistd.h> + +#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, "waitpid"); +} + +/* + * 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); +} |