4.4BSD/usr/src/usr.bin/xargs/xargs.c
/*-
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*/
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1990, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)xargs.c 8.1 (Berkeley) 6/6/93";
#endif /* not lint */
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include "pathnames.h"
int tflag, rval;
void err __P((const char *, ...));
void run __P((char **));
void usage __P((void));
main(argc, argv)
int argc;
char **argv;
{
register int ch;
register char *p, *bbp, *ebp, **bxp, **exp, **xp;
int cnt, indouble, insingle, nargs, nflag, nline, xflag;
char **av, *argp;
/*
* POSIX.2 limits the exec line length to ARG_MAX - 2K. Running that
* caused some E2BIG errors, so it was changed to ARG_MAX - 4K. Given
* that the smallest argument is 2 bytes in length, this means that
* the number of arguments is limited to:
*
* (ARG_MAX - 4K - LENGTH(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;
nline = ARG_MAX - 4 * 1024;
nflag = xflag = 0;
while ((ch = getopt(argc, argv, "n:s:tx")) != EOF)
switch(ch) {
case 'n':
nflag = 1;
if ((nargs = atoi(optarg)) <= 0)
err("illegal argument count");
break;
case 's':
nline = atoi(optarg);
break;
case 't':
tflag = 1;
break;
case 'x':
xflag = 1;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (xflag && !nflag)
usage();
/*
* Allocate pointers for the utility name, the utility arguments,
* the maximum arguments to be read from stdin and the trailing
* NULL.
*/
if (!(av = bxp =
malloc((u_int)(1 + argc + nargs + 1) * sizeof(char **))))
err("%s", strerror(errno));
/*
* 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)
cnt = strlen(*bxp++ = _PATH_ECHO);
else {
cnt = 0;
do {
cnt += strlen(*bxp++ = *argv) + 1;
} while (*++argv);
}
/*
* 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.
*/
exp = (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)
err("insufficient space for command");
if (!(bbp = malloc((u_int)nline + 1)))
err("%s", strerror(errno));
ebp = (argp = p = bbp) + nline - 1;
for (insingle = indouble = 0;;)
switch(ch = getchar()) {
case EOF:
/* No arguments since last exec. */
if (p == bbp)
exit(rval);
/* Nothing since end of last argument. */
if (argp == p) {
*xp = NULL;
run(av);
exit(rval);
}
goto arg1;
case ' ':
case '\t':
/* Quotes escape tabs and spaces. */
if (insingle || indouble)
goto addch;
goto arg2;
case '\n':
/* Empty lines are skipped. */
if (argp == p)
continue;
/* Quotes do not escape newlines. */
arg1: if (insingle || indouble)
err("unterminated quote");
arg2: *p = '\0';
*xp++ = 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.
*/
if (xp == exp || p == ebp || ch == EOF) {
if (xflag && xp != exp && p == ebp)
err("insufficient space for arguments");
*xp = NULL;
run(av);
if (ch == EOF)
exit(rval);
p = bbp;
xp = bxp;
} else
++p;
argp = p;
break;
case '\'':
if (indouble)
goto addch;
insingle = !insingle;
break;
case '"':
if (insingle)
goto addch;
indouble = !indouble;
break;
case '\\':
/* Backslash escapes anything, is escaped by quotes. */
if (!insingle && !indouble && (ch = getchar()) == EOF)
err("backslash at EOF");
/* FALLTHROUGH */
default:
addch: if (p < ebp) {
*p++ = ch;
break;
}
/* If only one argument, not enough buffer space. */
if (bxp == xp)
err("insufficient space for argument");
/* Didn't hit argument limit, so if xflag object. */
if (xflag)
err("insufficient space for arguments");
*xp = NULL;
run(av);
xp = bxp;
cnt = ebp - argp;
bcopy(argp, bbp, cnt);
p = (argp = bbp) + cnt;
*p++ = ch;
break;
}
/* NOTREACHED */
}
void
run(argv)
char **argv;
{
volatile int noinvoke;
register char **p;
pid_t pid;
int status;
if (tflag) {
(void)fprintf(stderr, "%s", *argv);
for (p = argv + 1; *p; ++p)
(void)fprintf(stderr, " %s", *p);
(void)fprintf(stderr, "\n");
(void)fflush(stderr);
}
noinvoke = 0;
switch(pid = vfork()) {
case -1:
err("vfork: %s", strerror(errno));
case 0:
execvp(argv[0], argv);
(void)fprintf(stderr,
"xargs: %s: %s\n", argv[0], strerror(errno));
noinvoke = 1;
_exit(1);
}
pid = waitpid(pid, &status, 0);
if (pid == -1)
err("waitpid: %s", strerror(errno));
/* If we couldn't invoke the utility, exit 127. */
if (noinvoke)
exit(127);
/* If utility signaled or exited with a value of 255, exit 1-125. */
if (WIFSIGNALED(status) || WEXITSTATUS(status) == 255)
exit(1);
if (WEXITSTATUS(status))
rval = 1;
}
void
usage()
{
(void)fprintf(stderr,
"usage: xargs [-t] [-n number [-x]] [-s size] [utility [argument ...]]\n");
exit(1);
}
#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif
void
#if __STDC__
err(const char *fmt, ...)
#else
err(fmt, va_alist)
char *fmt;
va_dcl
#endif
{
va_list ap;
#if __STDC__
va_start(ap, fmt);
#else
va_start(ap);
#endif
(void)fprintf(stderr, "xargs: ");
(void)vfprintf(stderr, fmt, ap);
va_end(ap);
(void)fprintf(stderr, "\n");
exit(1);
/* NOTREACHED */
}