awesome/common/util.c
Uli Schlachter 05a8ef2ed9 Handle execv() errors
Previously, awesome would just crash when execv() fails, because it already
destroyed all of its internal state, but then tries to do another main loop
iteration. Whoops.

Signed-off-by: Uli Schlachter <psychon@znc.in>
2012-07-15 00:18:44 +02:00

128 lines
3.3 KiB
C

/*
* util.c - useful functions
*
* Copyright © 2007-2008 Julien Danjou <julien@danjou.info>
* Copyright © 2006 Pierre Habouzit <madcoder@debian.org>
*
* 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 <stdarg.h>
#include <sys/wait.h>
#include <unistd.h>
#include <limits.h>
#include <fcntl.h>
#include <errno.h>
#include "common/util.h"
/** Print error and exit with EXIT_FAILURE code.
*/
void
_fatal(int line, const char *fct, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
fprintf(stderr, "E: awesome: %s:%d: ", fct, line);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, "\n");
exit(EXIT_FAILURE);
}
/** Print error message on stderr.
*/
void
_warn(int line, const char *fct, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
fprintf(stderr, "W: awesome: %s:%d: ", fct, line);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, "\n");
}
/** \brief safe limited strcpy.
*
* Copies at most min(<tt>n-1</tt>, \c l) characters from \c src into \c dst,
* always adding a final \c \\0 in \c dst.
*
* \param[in] dst destination buffer.
* \param[in] n size of the buffer. Negative sizes are allowed.
* \param[in] src source string.
* \param[in] l maximum number of chars to copy.
*
* \return minimum of \c src \e length and \c l.
*/
ssize_t
a_strncpy(char *dst, ssize_t n, const char *src, ssize_t l)
{
ssize_t len = MIN(a_strlen(src), l);
if (n > 0)
{
ssize_t dlen = MIN(n - 1, len);
memcpy(dst, src, dlen);
dst[dlen] = '\0';
}
return len;
}
/** \brief safe strcpy.
*
* Copies at most <tt>n-1</tt> characters from \c src into \c dst, always
* adding a final \c \\0 in \c dst.
*
* \param[in] dst destination buffer.
* \param[in] n size of the buffer. Negative sizes are allowed.
* \param[in] src source string.
* \return \c src \e length. If this value is \>= \c n then the copy was
* truncated.
*/
ssize_t
a_strcpy(char *dst, ssize_t n, const char *src)
{
ssize_t len = a_strlen(src);
if (n > 0)
{
ssize_t dlen = MIN(n - 1, len);
memcpy(dst, src, dlen);
dst[dlen] = '\0';
}
return len;
}
/** Execute a command and replace the current process.
* \param cmd The command to execute.
*/
void
a_exec(const char *cmd)
{
static const char *shell = NULL;
if(!shell && !(shell = getenv("SHELL")))
shell = "/bin/sh";
execl(shell, shell, "-c", cmd, NULL);
fatal("execv() failed: %s", strerror(errno));
}
// vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80