Rewrite of xargs by Vladimir N. Oleynik

This commit is contained in:
Glenn L McGrath 2002-11-10 21:47:17 +00:00
parent 907a240b1c
commit f57674e9a9
4 changed files with 96 additions and 69 deletions

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@ -55,7 +55,7 @@ Glenn McGrath <bug1@optushome.com.au>
ar, dpkg, dpkg-deb
Vladimir Oleynik <dzo@simtreas.ru>
cmdedit; ports: ash, crond, stty, traceroute, telnetd, top;
cmdedit; xargs(current); ports: ash, crond, stty, traceroute, telnetd, top;
locale, various fixes
and irreconcilable critic of everything not perfect.
@ -81,7 +81,8 @@ Linus Torvalds <torvalds@transmeta.com>
mkswap, fsck.minix, mkfs.minix
Mark Whitley <markw@lineo.com> <markw@codepoet.org>
grep, sed, cut, xargs, style-guide, new-applet-HOWTO, bug fixes, etc.
grep, sed, cut, xargs(previous),
style-guide, new-applet-HOWTO, bug fixes, etc.
Charles P. Wright <cpwright@villagenet.com>
gzip, mini-netcat(nc)

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@ -113,7 +113,7 @@ Glenn McGrath <bug1@netconnect.com.au>
Vladimir Oleynik <dzo@simtreas.ru>
cmdedit; ports: ash, crond, stty, traceroute, telnetd, top;
cmdedit, xargs(current); ports: ash, crond, stty, traceroute, telnetd, top;
locale, various fixes
and irreconcilable critic of everything not perfect.
@ -167,4 +167,4 @@ Enrique Zanardi <ezanardi@ull.es>
=cut
# $Id: busybox_footer.pod,v 1.7 2002/10/22 12:24:56 andersen Exp $
# $Id: busybox_footer.pod,v 1.8 2002/11/10 21:47:15 bug1 Exp $

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@ -1,9 +1,10 @@
/*
* Mini xargs implementation for busybox
* Only "-prt" options are supported in this version of xargs.
*
* Copyright (C) 1999,2000 by Lineo, inc. and Erik Andersen
* Copyright (C) 1999,2000,2001 by Erik Andersen <andersee@debian.org>
* Remixed by Mark Whitley <markw@codepoet.org>
* (C) 2002 by Vladimir Oleynik <dzo@simtreas.ru>
*
* Special thanks Mark Whitley for stimul to rewrote :)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@ -23,84 +24,105 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <getopt.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include "busybox.h"
/*
This function have special algorithm.
Don`t use fork and include to main!
*/
static void xargs_exec(char * const * args)
{
int p;
int common[4]; /* shared vfork stack */
common[0] = 0;
if ((p = vfork()) >= 0) {
if (p == 0) {
/* vfork -- child */
execvp(args[0], args);
common[0] = errno; /* set error to shared stack */
_exit(1);
} else {
/* vfork -- parent */
wait(NULL);
if(common[0]) {
errno = common[0];
perror_msg_and_die("%s", args[0]);
}
}
} else {
perror_msg_and_die("vfork");
}
}
int xargs_main(int argc, char **argv)
{
char *cmd_to_be_executed;
char *file_to_act_on;
int i;
int len;
char **args;
int i, a;
char flg_vi = 0; /* verbose |& interactive */
char flg_no_empty = 0;
/*
* No options are supported in this version of xargs; no getopt.
*
* Re: The missing -t flag: Most programs that produce output also print
* the filename, so xargs doesn't really need to do it again. Supporting
* the -t flag =greatly= bloats up the size of this app and the memory it
* uses because you have to buffer all the input file strings in memory. If
* you really want to see the filenames that xargs will act on, just run it
* once with no args and xargs will echo the filename. Simple.
*/
while ((a = getopt(argc, argv, "prt")) > 0) {
switch(a) {
case 'p':
flg_vi |= 3;
break;
case 't':
flg_vi |= 1;
break;
case 'r':
flg_no_empty = 1;
break;
default:
show_usage();
}
}
argv++;
len = argc; /* arg = count for ' ' + trailing '\0' */
/* Store the command to be executed (taken from the command line) */
if (argc == 1) {
a = argc - optind;
argv += optind;
if(a==0) {
/* default behavior is to echo all the filenames */
argv[0] = "/bin/echo";
len++; /* space for trailing '\0' */
} else {
argc--;
}
/* concatenate all the arguments passed to xargs together */
for (i = 0; i < argc; i++)
len += strlen(argv[i]);
cmd_to_be_executed = xmalloc (len);
for (i = len = 0; i < argc; i++) {
len = sprintf(cmd_to_be_executed + len, "%s ", argv[i]);
*argv = "/bin/echo";
a++;
}
/* allocating pointers for execvp: a*arg, arg from stdin, NULL */
args = xcalloc(a + 3, sizeof(char *));
/* Store the command to be executed (taken from the command line) */
for (i = 0; i < a; i++)
args[i] = *argv++;
/* Now, read in one line at a time from stdin, and store this
* line to be used later as an argument to the command */
while ((file_to_act_on = get_line_from_file(stdin)) !=NULL) {
FILE *cmd_output;
char *output_line;
char *execstr;
while ((file_to_act_on = get_line_from_file(stdin)) != NULL) {
/* eat the newline off the filename. */
chomp(file_to_act_on);
/* eat blank lines */
if (file_to_act_on[0] == 0)
continue;
/* assemble the command and execute it */
bb_asprintf(&execstr, "%s%s", cmd_to_be_executed, file_to_act_on);
cmd_output = popen(execstr, "r");
if (cmd_output == NULL)
perror_msg_and_die("popen");
/* harvest the output */
while ((output_line = get_line_from_file(cmd_output)) != NULL) {
fputs(output_line, stdout);
free(output_line);
if(file_to_act_on[0] != 0 || flg_no_empty == 0) {
args[a] = file_to_act_on[0] ? file_to_act_on : NULL;
if(flg_vi) {
for(i=0; args[i]; i++) {
if(i)
fputc(' ', stderr);
fputs(args[i], stderr);
}
fprintf(stderr, "%s", ((flg_vi & 2) ? " ?..." : "\n"));
}
if((flg_vi & 2) == 0 || ask_confirmation() != 0 ) {
xargs_exec(args);
}
}
/* clean up */
pclose(cmd_output);
free(execstr);
free(file_to_act_on);
}
#ifdef CONFIG_FEATURE_CLEAN_UP
free(cmd_to_be_executed);
free(args);
#endif
return 0;
}
/* vi: set sw=4 ts=4: */

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@ -2243,9 +2243,13 @@
"Prints the user name associated with the current effective user id."
#define xargs_trivial_usage \
"[COMMAND] [ARGS...]"
"[COMMAND] [-prt] [ARGS...]"
#define xargs_full_usage \
"Executes COMMAND on every item given by standard input."
"Executes COMMAND on every item given by standard input.\n\n" \
"Options:\n" \
"\t-p\tPrompt the user about whether to run each command\n" \
"\t-r\tDo not run command for empty readed lines\n" \
"\t-t\tPrint the command line on stderr before executing it."
#define xargs_example_usage \
"$ ls | xargs gzip\n" \
"$ find . -name '*.c' -print | xargs rm\n"