freebsd-dev/usr.bin/xargs/xargs.c
Jean-Marc Zucconi ef9866be68 xargs was spliting the input in a very different way from everyone else,
and was also a bit inconsistent: leading blanks, or any double blanks
generated empty arguments, but a trailing blank did not.

PR:		bin/2630, bin/10914
Submitted by:	Arne Henrik Juul <arnej@imf.unit.no>
1999-05-23 15:58:22 +00:00

314 lines
8.0 KiB
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 const char copyright[] =
"@(#) Copyright (c) 1990, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)xargs.c 8.1 (Berkeley) 6/6/93";
#endif
static const char rcsid[] =
"$Id: xargs.c,v 1.7 1998/10/13 14:52:32 des Exp $";
#endif /* not lint */
#include <sys/types.h>
#include <sys/wait.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "pathnames.h"
int tflag, rval;
int zflag;
void run __P((char **));
static void usage __P((void));
int
main(argc, argv, env)
int argc;
char **argv, **env;
{
register int ch;
register char *p, *bbp, *ebp, **bxp, **exp, **xp;
int cnt, indouble, insingle, nargs, nflag, nline, xflag, wasquoted;
char **av, *argp, **ep = env;
long arg_max;
/*
* 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;
if ((arg_max = sysconf(_SC_ARG_MAX)) == -1)
errx(1, "sysconf(_SC_ARG_MAX) failed");
nline = arg_max - 4 * 1024;
while (*ep) {
/* 1 byte for each '\0' */
nline -= strlen(*ep++) + 1 + sizeof(*ep);
}
nflag = xflag = wasquoted = 0;
while ((ch = getopt(argc, argv, "0n:s:tx")) != -1)
switch(ch) {
case 'n':
nflag = 1;
if ((nargs = atoi(optarg)) <= 0)
errx(1, "illegal argument count");
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 (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 **))))
errx(1, "malloc");
/*
* 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)
errx(1, "insufficient space for command");
if (!(bbp = malloc((u_int)nline + 1)))
errx(1, "malloc");
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);
goto arg1;
case ' ':
case '\t':
/* Quotes escape tabs and spaces. */
if (insingle || indouble || zflag)
goto addch;
goto arg2;
case '\0':
if (zflag)
goto arg2;
goto addch;
case '\n':
if (zflag)
goto addch;
/* Quotes do not escape newlines. */
arg1: if (insingle || indouble)
errx(1, "unterminated quote");
arg2:
/* Do not make empty args unless they are quoted */
if (argp != p || wasquoted) {
*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)
errx(1, "insufficient space for arguments");
*xp = NULL;
run(av);
if (ch == EOF)
exit(rval);
p = bbp;
xp = bxp;
}
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");
*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 = fork()) {
case -1:
err(1, "fork");
case 0:
execvp(argv[0], argv);
warn("%s", argv[0]);
noinvoke = 1;
_exit(1);
}
pid = waitpid(pid, &status, 0);
if (pid == -1)
err(1, "waitpid");
/* 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;
}
static void
usage()
{
(void)fprintf(stderr,
"usage: xargs [-0] [-t] [-n number [-x]] [-s size] [utility [argument ...]]\n");
exit(1);
}