glibc/posix/wordexp.c

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1995-02-18 01:27:10 +00:00
/* Copyright (C) 1992 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <sys/types.h>
#include <wordexp.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>
#include <signal.h>
/* We do word expansion with a pipe to the shell.
The shell command `sh [-P] [-u] -w "words ..."' expands words.
If -P, command substitution is an error.
If -u, reference to an undefined variable is an error.
The shell writes on its stdout:
%u\0 Number of words.
%u\0 Number of bytes in all words together (not counting \0s).
word1\0
word2\0
...
wordN\0
*/
#define SHELL_PATH "/bin/sh"
#define SHELL_NAME "sh"
int
DEFUN(wordexp, (string, pwordexp, flags),
CONST char *string AND wordexp_t *pwordexp AND int flags)
{
int error;
pid_t pid;
int d[2];
int status;
FILE *f;
size_t wordc, start, buflen;
char *buf;
/* Create the pipe through which we will communicate to the shell. */
if (pipe (d) < 0)
return -1;
pid = fork ();
if (pid < 0)
return -1;
if (pid == 0)
{
/* Child. Run the shell. */
CONST char *argv[5];
close (d[STDIN_FILENO]);
dup2 (d[STDOUT_FILENO], STDOUT_FILENO);
if (!(flags & WRDE_SHOWERR))
close (STDERR_FILENO);
i = 0;
argv[i++] = SHELL_NAME;
if (flags & WRDE_NOCMD)
argv[i++] = "-P";
if (flags & WRDE_UNDEF)
argv[i++] = "-u";
argv[i++] = "-w";
argv[i++] = string;
argv[i++] = NULL;
execv (SHELL_PATH, argv);
_exit (WRDE_NOSPACE);
}
/* Parent. */
buf = NULL;
error = WRDE_NOSPACE;
close (d[STDOUT_FILENO]);
f = fdopen (d[STDIN_FILENO]);
if (f == NULL)
goto lose;
/* Read the number of words and number of bytes from the shell. */
if (fscanf (f, "%u", &wordc) != 1 || getc (f) != '\0' ||
fscanf (f, "%u", &buflen) != 1 || getc (f) != '\0')
goto lose;
/* Read the words from the shell, and wait for it to return. */
buflen += wordc;
buf = malloc (buflen);
if (buf == NULL ||
fread (buf, buflen, 1, f) != 1 ||
waitpid (pid, &status, 0) != pid)
goto lose;
if (WIFEXITED (status))
{
if (WEXITSTATUS (status) != 0)
{
error = WEXITSTATUS (status);
goto lose;
}
}
else
goto lose;
/* Pack the structure. */
start = 0;
if (flags & WRDE_DOOFFS)
start += pwordexp->we_offs;
if (flags & WRDE_APPEND)
start += pwordexp->we_wordc;
wordc = start + wordc + 1;
if (flags & WRDE_APPEND)
wordv = (char **) realloc ((PTR) pwordexp->we_wordv,
wordc * sizeof (char *));
else
wordv = (char **) malloc (wordc * sizeof (char *));
if (wordv == NULL)
goto lose;
if (flags & WRDE_DOOFFS)
for (i = 0; i < pwordexp->we_offs; ++i)
wordv[i] = NULL;
for (i = start; i < wordc; ++i)
{
pwordexp->we_wordv[i] = buf;
buf = strchr (buf, '\0') + 1;
}
wordv[i] = NULL;
if (flags & WRDE_REUSE)
{
free (pwordexp->we_wordv[0]);
if (!(flags & WRDE_APPEND))
free (pwordexp->we_wordv);
}
pwordexp->we_wordc = wordc;
pwordexp->we_wordv = wordv;
return 0;
lose:
{
int save;
save = errno;
(void) kill (pid, SIGKILL);
free (buf);
(void) waitpid (pid, (int *) NULL, 0);
errno = save;
return error;
}
}
void
DEFUN(wordexp, (pwordexp), wordexp_t *pwordexp)
{
/* All the other elts point into the first. */
free (pwordexp->we_wordv[0]);
free (pwordexp->we_wordv);
}