/*
dropin.c -- a set of drop-in replacements for libc functions
- Copyright (C) 2000 Ivo Timmermans <itimmermans@bigfoot.com>,
- 2000 Guus Sliepen <guus@sliepen.warande.net>
+ Copyright (C) 2000-2003 Ivo Timmermans <ivo@o2w.nl>,
+ 2000-2003 Guus Sliepen <guus@sliepen.eu.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
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: dropin.c,v 1.1.2.1 2000/11/28 23:23:41 zarq Exp $
+ $Id: dropin.c,v 1.1.2.14 2003/07/12 17:48:38 guus Exp $
*/
#include "config.h"
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+
+#include <xalloc.h>
#include <system.h>
+#include <errno.h>
#ifndef HAVE_DAEMON
+/*
+ Replacement for the daemon() function.
+
+ The daemon() function is for programs wishing to detach themselves
+ from the controlling terminal and run in the background as system
+ daemons.
+
+ Unless the argument nochdir is non-zero, daemon() changes the
+ current working directory to the root (``/'').
+
+ Unless the argument noclose is non-zero, daemon() will redirect
+ standard input, standard output and standard error to /dev/null.
+*/
int daemon(int nochdir, int noclose)
{
- pid_t pid;
- int fd;
-
- pid = fork();
-
- /* Check if forking failed */
-
- if(pid < 0)
- {
- perror("fork");
- exit(-1);
- }
-
- /* If we are the parent, terminate */
-
- if(pid)
- exit(0);
+ pid_t pid;
+ int fd;
+
+ pid = fork();
+
+ /* Check if forking failed */
+ if(pid < 0) {
+ perror("fork");
+ exit(-1);
+ }
+
+ /* If we are the parent, terminate */
+ if(pid)
+ exit(0);
+
+ /* Detach by becoming the new process group leader */
+ if(setsid() < 0) {
+ perror("setsid");
+ return -1;
+ }
+
+ /* Change working directory to the root (to avoid keeping mount
+ points busy) */
+ if(!nochdir) {
+ chdir("/");
+ }
+
+ /* Redirect stdin/out/err to /dev/null */
+ if(!noclose) {
+ fd = open("/dev/null", O_RDWR);
+
+ if(fd < 0) {
+ perror("opening /dev/null");
+ return -1;
+ } else {
+ dup2(fd, 0);
+ dup2(fd, 1);
+ dup2(fd, 2);
+ }
+ }
+
+ return 0;
+}
+#endif
- /* Detach by becoming the new process group leader */
-
- if(setsid() < 0)
- {
- perror("setsid");
- return -1;
- }
-
- /* Change working directory to the root (to avoid keeping mount points busy) */
-
- if(!nochdir)
- {
- chdir("/");
- }
-
- /* Redirect stdin/out/err to /dev/null */
-
- if(!noclose)
- {
- fd = open("/dev/null", O_RDWR);
-
- if(fd < 0)
- {
- perror("opening /dev/null");
- return -1;
- }
- else
- {
- dup2(fd, 0);
- dup2(fd, 1);
- dup2(fd, 2);
- }
- }
+#ifndef HAVE_GET_CURRENT_DIR_NAME
+/*
+ Replacement for the GNU get_current_dir_name function:
+
+ get_current_dir_name will malloc(3) an array big enough to hold the
+ current directory name. If the environment variable PWD is set, and
+ its value is correct, then that value will be returned.
+*/
+char *get_current_dir_name(void)
+{
+ size_t size;
+ char *buf;
+ char *r;
+
+ /* Start with 100 bytes. If this turns out to be insufficient to
+ contain the working directory, double the size. */
+ size = 100;
+ buf = xmalloc(size);
+
+ errno = 0; /* Success */
+ r = getcwd(buf, size);
+
+ /* getcwd returns NULL and sets errno to ERANGE if the bufferspace
+ is insufficient to contain the entire working directory. */
+ while(r == NULL && errno == ERANGE) {
+ free(buf);
+ size <<= 1; /* double the size */
+ buf = xmalloc(size);
+ r = getcwd(buf, size);
+ }
+
+ return buf;
}
#endif
+#ifndef HAVE_ASPRINTF
+int asprintf(char **buf, const char *fmt, ...)
+{
+ int status;
+ va_list ap;
+ int len;
+ len = 4096;
+ *buf = xmalloc(len);
+ va_start(ap, fmt);
+ status = vsnprintf(*buf, len, fmt, ap);
+ va_end(ap);
+ if(status >= 0)
+ *buf = xrealloc(*buf, status);
-#ifndef HAVE_GET_CURRENT_DIR_NAME
+ if(status > len - 1) {
+ len = status;
+ va_start(ap, fmt);
+ status = vsnprintf(*buf, len, fmt, ap);
+ va_end(ap);
+ }
-char *get_current_dir_name(void)
-{
- return ".";
+ return status;
}
-
#endif
projects / tinc / blobdiff