Add in xargs

1 files changed, 922 insertions, 0 deletions

diff --git a/findutils/xargs.c b/findutils/xargs.c
new file mode 100644
index 0000000..73b1a02
--- /dev/null
+++ b/findutils/xargs.c
@@ -0,0 +1,922 @@
+/* xargs for busybox */
+
+/* xargs -- build and execute command lines from standard input
+   Copyright (C) 1990, 91, 92, 93, 94 Free Software Foundation, Inc.
+
+   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
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+/* Written by Mike Rendell <michael@cs.mun.ca>
+   and David MacKenzie <djm@gnu.ai.mit.edu>.  */
+
+#include "internal.h"
+
+#define HAVE_STRING_H 1
+#define HAVE_SYS_WAIT_H 1
+#define HAVE_UNISTD_H 1
+#define HAVE_LIMITS_H 1
+#define STDC_HEADERS 1
+
+#include <sys/types.h>		/* For pid_t. */
+#if HAVE_SYS_WAIT_H
+#include <sys/wait.h>
+#endif
+
+#ifndef WIFSTOPPED
+#define WIFSTOPPED(w) (((w) & 0xff) == 0x7f)
+#endif
+#ifndef WIFSIGNALED
+#define WIFSIGNALED(w) (((w) & 0xff) != 0x7f && ((w) & 0xff) != 0)
+#endif
+#ifndef WIFEXITED
+#define WIFEXITED(w) (((w) & 0xff) == 0)
+#endif
+
+#ifndef WSTOPSIG
+#define WSTOPSIG(w) (((w) >> 8) & 0xff)
+#endif
+#ifndef WTERMSIG
+#define WTERMSIG(w) ((w) & 0x7f)
+#endif
+#ifndef WEXITSTATUS
+#define WEXITSTATUS(w) (((w) >> 8) & 0xff)
+#endif
+
+#if __STDC__
+#define P_(s) s
+#else
+#define P_(s) ()
+#endif
+
+#include <ctype.h>
+
+#if !defined (isascii) || defined (STDC_HEADERS)
+#ifdef isascii
+#undef isascii
+#endif
+#define isascii(c) 1
+#endif
+
+#ifdef isblank
+#define ISBLANK(c) (isascii (c) && isblank (c))
+#else
+#define ISBLANK(c) ((c) == ' ' || (c) == '\t')
+#endif
+
+#define ISSPACE(c) (ISBLANK (c) || (c) == '\n' || (c) == '\r' \
+		    || (c) == '\f' || (c) == '\v')
+
+#include <stdio.h>
+#include <errno.h>
+#include <getopt.h>
+
+#if defined(HAVE_STRING_H) || defined(STDC_HEADERS)
+#include <string.h>
+#if !defined(STDC_HEADERS)
+#include <memory.h>
+#endif
+#else
+#include <strings.h>
+#define memcpy(dest, source, count) (bcopy((source), (dest), (count)))
+#endif
+
+#ifndef _POSIX_SOURCE
+#include <sys/param.h>
+#endif
+
+#ifdef HAVE_LIMITS_H
+#include <limits.h>
+#endif
+
+#ifndef LONG_MAX
+#define LONG_MAX (~(1 << (sizeof (long) * 8 - 1)))
+#endif
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include <signal.h>
+
+#if !defined(SIGCHLD) && defined(SIGCLD)
+#define SIGCHLD SIGCLD
+#endif
+
+/* COMPAT:  SYSV version defaults size (and has a max value of) to 470.
+   We try to make it as large as possible. */
+#if !defined(ARG_MAX) && defined(_SC_ARG_MAX)
+#define ARG_MAX sysconf (_SC_ARG_MAX)
+#endif
+#ifndef ARG_MAX
+#define ARG_MAX NCARGS
+#endif
+
+/* States for read_line. */
+#define NORM 0
+#define SPACE 1
+#define QUOTE 2
+#define BACKSLASH 3
+
+#ifdef STDC_HEADERS
+#include <stdlib.h>
+#else
+extern int errno;
+#endif
+
+/* Return nonzero if S is the EOF string.  */
+#define EOF_STR(s) (eof_str && *eof_str == *s && !strcmp (eof_str, s))
+
+extern char **environ;
+
+/* Not char because of type promotion; NeXT gcc can't handle it.  */
+typedef int boolean;
+#define		true    1
+#define		false	0
+
+#if __STDC__
+#define VOID void
+#else
+#define VOID char
+#endif
+
+VOID *xmalloc P_ ((size_t n));
+VOID *xrealloc P_ ((VOID * p, size_t n));
+
+/* The name this program was run with.  */
+char *program_name;
+
+/* Buffer for reading arguments from stdin.  */
+static char *linebuf;
+
+/* Line number in stdin since the last command was executed.  */
+static int lineno = 0;
+
+/* If nonzero, then instead of putting the args from stdin at
+   the end of the command argument list, they are each stuck into the
+   initial args, replacing each occurrence of the `replace_pat' in the
+   initial args.  */
+static char *replace_pat = NULL;
+
+/* The length of `replace_pat'.  */
+static size_t rplen = 0;
+
+/* If nonzero, when this string is read on stdin it is treated as
+   end of file.
+   I don't like this - it should default to NULL.  */
+static char *eof_str = "_";
+
+/* If nonzero, the maximum number of nonblank lines from stdin to use
+   per command line.  */
+static long lines_per_exec = 0;
+
+/* The maximum number of arguments to use per command line.  */
+static long args_per_exec = 1024;
+
+/* If true, exit if lines_per_exec or args_per_exec is exceeded.  */
+static boolean exit_if_size_exceeded = false;
+
+/* The maximum number of characters that can be used per command line.  */
+static long arg_max;
+
+/* Storage for elements of `cmd_argv'.  */
+static char *argbuf;
+
+/* The list of args being built.  */
+static char **cmd_argv = NULL;
+
+/* Number of elements allocated for `cmd_argv'.  */
+static int cmd_argv_alloc = 0;
+
+/* Number of valid elements in `cmd_argv'.  */
+static int cmd_argc = 0;
+
+/* Number of chars being used in `cmd_argv'.  */
+static int cmd_argv_chars = 0;
+
+/* Number of initial arguments given on the command line.  */
+static int initial_argc = 0;
+
+/* Number of chars in the initial args.  */
+static int initial_argv_chars = 0;
+
+/* true when building up initial arguments in `cmd_argv'.  */
+static boolean initial_args = true;
+
+/* If nonzero, the maximum number of child processes that can be running
+   at once.  */
+static int proc_max = 1;
+
+/* Total number of child processes that have been executed.  */
+static int procs_executed = 0;
+
+/* The number of elements in `pids'.  */
+static int procs_executing = 0;
+
+/* List of child processes currently executing.  */
+static pid_t *pids = NULL;
+
+/* The number of allocated elements in `pids'. */
+static int pids_alloc = 0;
+
+/* Exit status; nonzero if any child process exited with a
+   status of 1-125.  */
+static int child_error = 0;
+
+/* If true, print each command on stderr before executing it.  */
+static boolean print_command = false;
+
+/* If true, query the user before executing each command, and only
+   execute the command if the user responds affirmatively.  */
+static boolean query_before_executing = false;
+
+static struct option const longopts[] =
+{
+  {"null", no_argument, NULL, '0'},
+  {"eof", optional_argument, NULL, 'e'},
+  {"replace", optional_argument, NULL, 'i'},
+  {"max-lines", optional_argument, NULL, 'l'},
+  {"max-args", required_argument, NULL, 'n'},
+  {"interactive", no_argument, NULL, 'p'},
+  {"no-run-if-empty", no_argument, NULL, 'r'},
+  {"max-chars", required_argument, NULL, 's'},
+  {"verbose", no_argument, NULL, 't'},
+  {"exit", no_argument, NULL, 'x'},
+  {"max-procs", required_argument, NULL, 'P'},
+  {"help", no_argument, NULL, 'h'},
+  {NULL, no_argument, NULL, 0}
+};
+
+static int read_line P_ ((void));
+static int read_string P_ ((void));
+static void do_insert P_ ((char *arg, size_t arglen, size_t lblen));
+static void push_arg P_ ((char *arg, size_t len));
+static boolean print_args P_ ((boolean ask));
+static void do_exec P_ ((void));
+static void add_proc P_ ((pid_t pid));
+static void wait_for_proc P_ ((boolean all));
+static long parse_num P_ ((char *str, int option, long min, long max));
+static long env_size P_ ((char **envp));
+
+int xargs_main (argc, argv)
+     int argc;
+     char **argv;
+{
+  int optc;
+  int always_run_command = 1;
+  long orig_arg_max;
+  char *default_cmd = "/bin/echo";
+  int (*read_args) P_ ((void)) = read_line;
+
+  program_name = argv[0];
+
+  orig_arg_max = ARG_MAX;
+  if (orig_arg_max == -1)
+    orig_arg_max = LONG_MAX;
+  orig_arg_max -= 2048; /* POSIX.2 requires subtracting 2048.  */
+  arg_max = orig_arg_max;
+
+  /* Sanity check for systems with huge ARG_MAX defines (e.g., Suns which
+     have it at 1 meg).  Things will work fine with a large ARG_MAX but it
+     will probably hurt the system more than it needs to; an array of this
+     size is allocated.  */
+  if (arg_max > 20 * 1024)
+    arg_max = 20 * 1024;
+
+  /* Take the size of the environment into account.  */
+  arg_max -= env_size (environ);
+  if (arg_max <= 0)
+    fatalError("environment is too large for exec");
+
+  while ((optc = getopt_long (argc, argv, "+0e::i::l::n:prs:txP:",
+			      longopts, (int *) 0)) != -1)
+    {
+      switch (optc)
+	{
+	case '0':
+	  read_args = read_string;
+	  break;
+
+	case 'e':
+	  if (optarg)
+	    eof_str = optarg;
+	  else
+	    eof_str = 0;
+	  break;
+
+	case 'h':
+	  usage (xargs_usage);
+
+	case 'i':
+	  if (optarg)
+	    replace_pat = optarg;
+	  else
+	    replace_pat = "{}";
+	  /* -i excludes -n -l.  */
+	  args_per_exec = 0;
+	  lines_per_exec = 0;
+	  break;
+
+	case 'l':
+	  if (optarg)
+	    lines_per_exec = parse_num (optarg, 'l', 1L, -1L);
+	  else
+	    lines_per_exec = 1;
+	  /* -l excludes -i -n.  */
+	  args_per_exec = 0;
+	  replace_pat = NULL;
+	  break;
+
+	case 'n':
+	  args_per_exec = parse_num (optarg, 'n', 1L, -1L);
+	  /* -n excludes -i -l.  */
+	  lines_per_exec = 0;
+	  replace_pat = NULL;
+	  break;
+
+	case 's':
+	  arg_max = parse_num (optarg, 's', 1L, orig_arg_max);
+	  break;
+
+	case 't':
+	  print_command = true;
+	  break;
+
+	case 'x':
+	  exit_if_size_exceeded = true;
+	  break;
+
+	case 'p':
+	  query_before_executing = true;
+	  print_command = true;
+	  break;
+
+	case 'r':
+	  always_run_command = 0;
+	  break;
+
+	case 'P':
+	  proc_max = parse_num (optarg, 'P', 0L, -1L);
+	  break;
+
+	default:
+	  usage (xargs_usage);
+	}
+    }
+
+  if (replace_pat || lines_per_exec)
+    exit_if_size_exceeded = true;
+
+  if (optind == argc)
+    {
+      optind = 0;
+      argc = 1;
+      argv = &default_cmd;
+    }
+
+  linebuf = (char *) xmalloc (arg_max + 1);
+  argbuf = (char *) xmalloc (arg_max + 1);
+
+  /* Make sure to listen for the kids.  */
+  signal (SIGCHLD, SIG_DFL);
+
+  if (!replace_pat)
+    {
+      for (; optind < argc; optind++)
+	push_arg (argv[optind], strlen (argv[optind]) + 1);
+      initial_args = false;
+      initial_argc = cmd_argc;
+      initial_argv_chars = cmd_argv_chars;
+
+      while ((*read_args) () != -1)
+	if (lines_per_exec && lineno >= lines_per_exec)
+	  {
+	    do_exec ();
+	    lineno = 0;
+	  }
+
+      /* SYSV xargs seems to do at least one exec, even if the
+         input is empty.  */
+      if (cmd_argc != initial_argc
+	  || (always_run_command && procs_executed == 0))
+	do_exec ();
+    }
+  else
+    {
+      int i;
+      size_t len;
+      size_t *arglen = (size_t *) xmalloc (sizeof (size_t) * argc);
+
+      for (i = optind; i < argc; i++)
+	arglen[i] = strlen(argv[i]);
+      rplen = strlen (replace_pat);
+      while ((len = (*read_args) ()) != -1)
+	{
+	  /* Don't do insert on the command name.  */
+	  push_arg (argv[optind], arglen[optind] + 1);
+	  len--;
+	  for (i = optind + 1; i < argc; i++)
+	    do_insert (argv[i], arglen[i], len);
+	  do_exec ();
+	}
+    }
+
+  wait_for_proc (true);
+  exit (child_error);
+}
+
+/* Read a line of arguments from stdin and add them to the list of
+   arguments to pass to the command.  Ignore blank lines and initial blanks.
+   Single and double quotes and backslashes quote metacharacters and blanks
+   as they do in the shell.
+   Return -1 if eof (either physical or logical) is reached,
+   otherwise the length of the last string read (including the null).  */
+
+static int
+read_line ()
+{
+  static boolean eof = false;
+  /* Start out in mode SPACE to always strip leading spaces (even with -i).  */
+  int state = SPACE;		/* The type of character we last read.  */
+  int prevc;			/* The previous value of c.  */
+  int quotc = 0;		/* The last quote character read.  */
+  int c = EOF;
+  boolean first = true;		/* true if reading first arg on line.  */
+  int len;
+  char *p = linebuf;
+  /* Including the NUL, the args must not grow past this point.  */
+  char *endbuf = linebuf + arg_max - initial_argv_chars - 1;
+
+  if (eof)
+    return -1;
+  while (1)
+    {
+      prevc = c;
+      c = getc (stdin);
+      if (c == EOF)
+	{
+	  /* COMPAT: SYSV seems to ignore stuff on a line that
+	     ends without a \n; we don't.  */
+	  eof = true;
+	  if (p == linebuf)
+	    return -1;
+	  *p++ = '\0';
+	  len = p - linebuf;
+	  /* FIXME we don't check for unterminated quotes here.  */
+	  if (first && EOF_STR (linebuf))
+	    return -1;
+	  if (!replace_pat)
+	    push_arg (linebuf, len);
+	  return len;
+	}
+      switch (state)
+	{
+	case SPACE:
+	  if (ISSPACE (c))
+	    continue;
+	  state = NORM;
+	  /* aaahhhh....  */
+
+	case NORM:
+	  if (c == '\n')
+	    {
+	      if (!ISBLANK (prevc))
+		lineno++;	/* For -l.  */
+	      if (p == linebuf)
+		{
+		  /* Blank line.  */
+		  state = SPACE;
+		  continue;
+		}
+	      *p++ = '\0';
+	      len = p - linebuf;
+	      if (EOF_STR (linebuf))
+		{
+		  eof = true;
+		  return first ? -1 : len;
+		}
+	      if (!replace_pat)
+		push_arg (linebuf, len);
+	      return len;
+	    }
+	  if (!replace_pat && ISSPACE (c))
+	    {
+	      *p++ = '\0';
+	      len = p - linebuf;
+	      if (EOF_STR (linebuf))
+		{
+		  eof = true;
+		  return first ? -1 : len;
+		}
+	      push_arg (linebuf, len);
+	      p = linebuf;
+	      state = SPACE;
+	      first = false;
+	      continue;
+	    }
+	  switch (c)
+	    {
+	    case '\\':
+	      state = BACKSLASH;
+	      continue;
+
+	    case '\'':
+	    case '"':
+	      state = QUOTE;
+	      quotc = c;
+	      continue;
+	    }
+	  break;
+
+	case QUOTE:
+	  if (c == '\n')
+	    fatalError ("unmatched %s quote", quotc == '"' ? "double" : "single");
+	  if (c == quotc)
+	    {
+	      state = NORM;
+	      continue;
+	    }
+	  break;
+
+	case BACKSLASH:
+	  state = NORM;
+	  break;
+	}
+      if (p >= endbuf)
+	fatalError ("argument line too long");
+      *p++ = c;
+    }
+}
+
+/* Read a null-terminated string from stdin and add it to the list of
+   arguments to pass to the command.
+   Return -1 if eof (either physical or logical) is reached,
+   otherwise the length of the string read (including the null).  */
+
+static int
+read_string ()
+{
+  static boolean eof = false;
+  int len;
+  char *p = linebuf;
+  /* Including the NUL, the args must not grow past this point.  */
+  char *endbuf = linebuf + arg_max - initial_argv_chars - 1;
+
+  if (eof)
+    return -1;
+  while (1)
+    {
+      int c = getc (stdin);
+      if (c == EOF)
+	{
+	  eof = true;
+	  if (p == linebuf)
+	    return -1;
+	  *p++ = '\0';
+	  len = p - linebuf;
+	  if (!replace_pat)
+	    push_arg (linebuf, len);
+	  return len;
+	}
+      if (c == '\0')
+	{
+	  lineno++;		/* For -l.  */
+	  *p++ = '\0';
+	  len = p - linebuf;
+	  if (!replace_pat)
+	    push_arg (linebuf, len);
+	  return len;
+	}
+      if (p >= endbuf)
+	fatalError ("argument line too long");
+      *p++ = c;
+    }
+}
+
+/* Replace all instances of `replace_pat' in ARG with `linebuf',
+   and add the resulting string to the list of arguments for the command
+   to execute.
+   ARGLEN is the length of ARG, not including the null.
+   LBLEN is the length of `linebuf', not including the null.
+
+   COMPAT: insertions on the SYSV version are limited to 255 chars per line,
+   and a max of 5 occurences of replace_pat in the initial-arguments.
+   Those restrictions do not exist here.  */
+
+static void
+do_insert (arg, arglen, lblen)
+     char *arg;
+     size_t arglen;
+     size_t lblen;
+{
+  /* Temporary copy of each arg with the replace pattern replaced by the
+     real arg.  */
+  static char *insertbuf;
+  char *p;
+  int bytes_left = arg_max - 1;	/* Bytes left on the command line.  */
+
+  if (!insertbuf)
+    insertbuf = (char *) xmalloc (arg_max + 1);
+  p = insertbuf;
+
+  do
+    {
+      size_t len;		/* Length in ARG before `replace_pat'.  */
+      char *s = strstr (arg, replace_pat);
+      if (s)
+	len = s - arg;
+      else
+	len = arglen;
+      bytes_left -= len;
+      if (bytes_left <= 0)
+	break;
+
+      strncpy (p, arg, len);
+      p += len;
+      arg += len;
+      arglen -= len;
+
+      if (s)
+	{
+	  bytes_left -= lblen;
+	  if (bytes_left <= 0)
+	    break;
+	  strcpy (p, linebuf);
+	  arg += rplen;
+	  arglen -= rplen;
+	  p += lblen;
+	}
+    }
+  while (*arg);
+  if (*arg)
+    fatalError ("command too long");
+  *p++ = '\0';
+  push_arg (insertbuf, p - insertbuf);
+}
+
+/* Add ARG to the end of the list of arguments `cmd_argv' to pass
+   to the command.
+   LEN is the length of ARG, including the terminating null.
+   If this brings the list up to its maximum size, execute the command.  */
+
+static void
+push_arg (arg, len)
+     char *arg;
+     size_t len;
+{
+  if (arg)
+    {
+      if (cmd_argv_chars + len > arg_max)
+	{
+	  if (initial_args || cmd_argc == initial_argc)
+	    fatalError ("can not fit single argument within argument list size limit");
+	  if (replace_pat
+	      || (exit_if_size_exceeded &&
+		  (lines_per_exec || args_per_exec)))
+	    fatalError ("argument list too long");
+	  do_exec ();
+	}
+      if (!initial_args && args_per_exec &&
+	  cmd_argc - initial_argc == args_per_exec)
+	do_exec ();
+    }
+
+  if (cmd_argc >= cmd_argv_alloc)
+    {
+      if (!cmd_argv)
+	{
+	  cmd_argv_alloc = 64;
+	  cmd_argv = (char **) xmalloc (sizeof (char *) * cmd_argv_alloc);
+	}
+      else
+	{
+	  cmd_argv_alloc *= 2;
+	  cmd_argv = (char **) xrealloc (cmd_argv,
+					 sizeof (char *) * cmd_argv_alloc);
+	}
+    }
+
+  if (!arg)
+    cmd_argv[cmd_argc++] = NULL;
+  else
+    {
+      cmd_argv[cmd_argc++] = argbuf + cmd_argv_chars;
+      strcpy (argbuf + cmd_argv_chars, arg);
+      cmd_argv_chars += len;
+    }
+}
+
+/* Print the arguments of the command to execute.
+   If ASK is nonzero, prompt the user for a response, and
+   if the user responds affirmatively, return true;
+   otherwise, return false.  */
+
+static boolean
+print_args (ask)
+     boolean ask;
+{
+  int i;
+
+  for (i = 0; i < cmd_argc - 1; i++)
+    fprintf (stderr, "%s ", cmd_argv[i]);
+  if (ask)
+    {
+      static FILE *tty_stream;
+      int c, savec;
+
+      if (!tty_stream)
+	{
+	  tty_stream = fopen ("/dev/tty", "r");
+	  if (!tty_stream)
+	    fatalError (" Could not open /dev/tty");
+	}
+      fputs ("?...", stderr);
+      fflush (stderr);
+      c = savec = getc (tty_stream);
+      while (c != EOF && c != '\n')
+	c = getc (tty_stream);
+      if (savec == 'y' || savec == 'Y')
+	return true;
+    }
+  else
+    putc ('\n', stderr);
+
+  return false;
+}
+
+/* Execute the command that has been built in `cmd_argv'.  This may involve
+   waiting for processes that were previously executed.  */
+
+static void
+do_exec ()
+{
+  pid_t child;
+
+  push_arg ((char *) NULL, 0);	/* Null terminate the arg list.  */
+  if (!query_before_executing || print_args (true))
+    {
+      if (proc_max && procs_executing >= proc_max)
+	wait_for_proc (false);
+      if (!query_before_executing && print_command)
+	print_args (false);
+      /* If we run out of processes, wait for a child to return and
+         try again.  */
+      while ((child = fork ()) < 0 && errno == EAGAIN && procs_executing)
+	wait_for_proc (false);
+      switch (child)
+	{
+	case -1:
+	  fatalError ("cannot fork");
+
+	case 0:		/* Child.  */
+	  execvp (cmd_argv[0], cmd_argv);
+	  errorMsg ("failed to exec '%s'", cmd_argv[0]);
+	  _exit (errno == ENOENT ? 127 : 126);
+	}
+      add_proc (child);
+    }
+
+  cmd_argc = initial_argc;
+  cmd_argv_chars = initial_argv_chars;
+}
+
+/* Add the process with id PID to the list of processes that have
+   been executed.  */
+
+static void
+add_proc (pid)
+     pid_t pid;
+{
+  int i;
+
+  /* Find an empty slot.  */
+  for (i = 0; i < pids_alloc && pids[i]; i++)
+    ;
+  if (i == pids_alloc)
+    {
+      if (pids_alloc == 0)
+	{
+	  pids_alloc = proc_max ? proc_max : 64;
+	  pids = (pid_t *) xmalloc (sizeof (pid_t) * pids_alloc);
+	}
+      else
+	{
+	  pids_alloc *= 2;
+	  pids = (pid_t *) xrealloc (pids,
+				     sizeof (pid_t) * pids_alloc);
+	}
+      memset (&pids[i], '\0', sizeof (pid_t) * (pids_alloc - i));
+    }
+  pids[i] = pid;
+  procs_executing++;
+  procs_executed++;
+}
+
+/* If ALL is true, wait for all child processes to finish;
+   otherwise, wait for one child process to finish.
+   Remove the processes that finish from the list of executing processes.  */
+
+static void
+wait_for_proc (all)
+     boolean all;
+{
+  while (procs_executing)
+    {
+      int i, status;
+
+      do
+	{
+	  pid_t pid;
+
+	  pid = wait (&status);
+	  if (pid < 0)
+	    fatalError ("error waiting for child process");
+
+	  /* Find the entry in `pids' for the child process
+	     that exited.  */
+	  for (i = 0; i < pids_alloc && pid != pids[i]; i++)
+	    ;
+	}
+      while (i == pids_alloc);	/* A child died that we didn't start? */
+
+      /* Remove the child from the list.  */
+      pids[i] = 0;
+      procs_executing--;
+
+      if (WEXITSTATUS (status) == 126 || WEXITSTATUS (status) == 127)
+	exit (WEXITSTATUS (status));	/* Can't find or run the command.  */
+      if (WEXITSTATUS (status) == 255)
+	fatalError ( "%s: exited with status 255; aborting", cmd_argv[0]);
+      if (WIFSTOPPED (status))
+	fatalError ( "%s: stopped by signal %d", cmd_argv[0], WSTOPSIG (status));
+      if (WIFSIGNALED (status))
+	fatalError ("%s: terminated by signal %d", cmd_argv[0], WTERMSIG (status));
+      if (WEXITSTATUS (status) != 0)
+	child_error = 123;
+
+      if (!all)
+	break;
+    }
+}
+
+/* Return the value of the number represented in STR.
+   OPTION is the command line option to which STR is the argument.
+   If the value does not fall within the boundaries MIN and MAX,
+   Print an error message mentioning OPTION and exit.  */
+
+static long
+parse_num (str, option, min, max)
+     char *str;
+     int option;
+     long min;
+     long max;
+{
+  char *eptr;
+  long val;
+
+  val = strtol (str, &eptr, 10);
+  if (eptr == str || *eptr)
+    {
+      fprintf (stderr, "%s: invalid number for -%c option\n",
+	       program_name, option);
+      usage (xargs_usage);
+    }
+  else if (val < min)
+    {
+      fprintf (stderr, "%s: value for -%c option must be >= %ld\n",
+	       program_name, option, min);
+      usage (xargs_usage);
+    }
+  else if (max >= 0 && val > max)
+    {
+      fprintf (stderr, "%s: value for -%c option must be < %ld\n",
+	       program_name, option, max);
+      usage (xargs_usage);
+    }
+  return val;
+}
+
+/* Return how much of ARG_MAX is used by the environment.  */
+
+static long
+env_size (envp)
+     char **envp;
+{
+  long len = 0;
+
+  while (*envp)
+    len += strlen (*envp++) + 1;
+
+  return len;
+}
+