Rewrite of xargs by Vladimir N. Oleynik

diff --git a/AUTHORS b/AUTHORS
index b6dadf4..6cd8ab8 100644 (file)
--- a/AUTHORS
+++ b/AUTHORS
@@ -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)

diff --git a/docs/busybox_footer.pod b/docs/busybox_footer.pod
index 96d074f..1506768 100644 (file)
--- a/docs/busybox_footer.pod
+++ b/docs/busybox_footer.pod
@@ -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 $

diff --git a/findutils/xargs.c b/findutils/xargs.c
index 471bae4..677618d 100644 (file)
--- a/findutils/xargs.c
+++ b/findutils/xargs.c
@@ -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: */

diff --git a/include/usage.h b/include/usage.h
index d0aa324..c140a88 100644 (file)
--- a/include/usage.h
+++ b/include/usage.h
@@ -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"