/* $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);
}
