Return to cmd_exec.c CVS log

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Mostly clean-up:
- cut up those huge include files into separate interfaces for all modules.
Put the interface documentation there, and not with the implementation.
- light-weight includes for needed concrete types (lst_t.h, timestamp_t.h).
- cut out some more logically separate parts: cmd_exec, varname, parsevar,
timestamp.
- put all error handling functions together, so that we will be able to
clean them up.
- more systematic naming: functioni  to handle interval, function to handle
string.
- put the init/end code apart to minimize coupling.
- kill weird types like ReturnStatus and Boolean. Use standard bool (with a
fallback for non-iso systems)
- better interface documentation for lots of subsystems.

As a result, make compilation goes somewhat faster (5%, even considering
the largish BSD copyrights to read). The corresponding preprocessed
source goes down from 1,5M to 1M.

A few minor code changes as well: Parse_DoVar is no longer destructive.
Parse_IsVar functionality is folded into Parse_DoVar (as it knows what an
assignment is), a few more interval handling functions. Avoid calling
XXX_End when they do nothing, just #define XXX_End   to nothing.

Parse_DoVar is slightly more general: it will handle compound assignments
as long as they make sense, e.g., VAR +!= cmd
will work.  As a side effect, VAR++=value now triggers an error
(two + in assignment).
- this stuff doesn't occur in portable Makefiles.
- writing VAR++ = value or VAR+ +=value  disambiguates it.
- this is a good thing, it uncovered a bug in bsd.port.mk.

Tested by naddy@. Okayed millert@. I'll handle the fallback if there is
any. This went through a full make build anyways, including isakmpd
(without mickey's custom binutils, as he didn't see fit to share it with me).

/*	$OpenPackages$ */
/*	$OpenBSD: cmd_exec.c,v 1.1 2001/05/23 12:34:40 espie Exp $ */
/*
 * Copyright (c) 2001 Marc Espie.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT 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 OPENBSD
 * PROJECT 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.
 */

#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include "config.h"
#include "defines.h"
#include "cmd_exec.h"
#include "buf.h"
#include "memory.h"
#include "pathnames.h"

char *
Cmd_Exec(cmd, err)
    const char	*cmd;
    char	**err;
{
    char	*args[4];	/* Args for invoking the shell */
    int 	fds[2]; 	/* Pipe streams */
    pid_t 	cpid;		/* Child PID */
    pid_t 	pid;		/* PID from wait() */
    char	*result;	/* Result */
    int 	status; 	/* Command exit status */
    BUFFER	buf;		/* Buffer to store the result. */
    char	*cp;		/* Pointer into result. */
    ssize_t	cc;		/* Characters read from pipe. */
    size_t	length;		/* Total length of result. */


    *err = NULL;

    /* Set up arguments for the shell. */
    args[0] = "sh";
    args[1] = "-c";
    args[2] = (char *)cmd;
    args[3] = NULL;

    /* Open a pipe for retrieving shell's output. */
    if (pipe(fds) == -1) {
	*err = "Couldn't create pipe for \"%s\"";
	goto bad;
    }

    /* Fork */
    switch (cpid = vfork()) {
    case 0:
	/* Close input side of pipe */
	(void)close(fds[0]);

	/* Duplicate the output stream to the shell's output, then
	 * shut the extra thing down. Note we don't fetch the error
	 * stream: user can use redirection to grab it as this goes
	 * through /bin/sh.
	 */
	(void)dup2(fds[1], 1);
	if (fds[1] != 1)
	    (void)close(fds[1]);

	(void)execv(_PATH_BSHELL, args);
	_exit(1);
	/*NOTREACHED*/

    case -1:
	*err = "Couldn't exec \"%s\"";
	goto bad;

    default:
	/* No need for the writing half. */
	(void)close(fds[1]);

	Buf_Init(&buf, MAKE_BSIZE);

	do {
	    char   grab[BUFSIZ];

	    cc = read(fds[0], grab, sizeof(grab));
	    if (cc > 0)
		Buf_AddChars(&buf, cc, grab);
	}
	while (cc > 0 || (cc == -1 && errno == EINTR));

	/* Close the input side of the pipe.  */
	(void)close(fds[0]);

	/* Wait for the child to exit.  */
	while ((pid = wait(&status)) != cpid && pid >= 0)
	    continue;

	if (cc == -1)
	    *err = "Couldn't read shell's output for \"%s\"";

	if (status)
	    *err = "\"%s\" returned non-zero status";

	length = Buf_Size(&buf);
	result = Buf_Retrieve(&buf);

	/* The result is null terminated, Convert newlines to spaces. */
	cp = result + length - 1;

	if (*cp == '\n')
	    /* A final newline is just stripped.  */
	    *cp-- = '\0';

	while (cp >= result) {
	    if (*cp == '\n')
		*cp = ' ';
	    cp--;
	}
	break;
    }
    return result;
bad:
    return estrdup("");
}