/*

    Copyright (C) 2012	RedHat 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 of the License, 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.,

    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

*/

#include "libabrt.h"

/* I want to use -Werror, but gcc-4.4 throws a curveball:

 * "warning: ignoring return value of 'ftruncate', declared with attribute warn_unused_result"

 * and (void) cast is not enough to shut it up! Oh God...

 */

#define IGNORE_RESULT(func_call) do { if (func_call) /* nothing */; } while (0)

int check_recent_crash_file(const char *filename, const char *executable)

{

    int fd = open(filename, O_RDWR | O_CREAT, 0600);

    if (fd < 0)

        return 0;

    int ex_len = strlen(executable);

    struct stat sb;

    int sz;

    fstat(fd, &sb); /* !paranoia. this can't fail. */

    if (sb.st_size != 0 /* if it wasn't created by us just now... */

     && (unsigned)(time(NULL) - sb.st_mtime) < 20 /* and is relatively new [is 20 sec ok?] */

    ) {

        char buf[ex_len + 2];

        sz = read(fd, buf, ex_len + 1);

        if (sz > 0)

        {

            buf[sz] = '\0';

            if (strcmp(executable, buf) == 0)

            {

                close(fd);

                return 1;

            }

        }

        lseek(fd, 0, SEEK_SET);

    }

    sz = write(fd, executable, ex_len);

    if (sz >= 0)

        IGNORE_RESULT(ftruncate(fd, sz));

    close(fd);

    return 0;

}