/* dropin.c -- a set of drop-in replacements for libc functions Copyright (C) 2000-2005 Ivo Timmermans, 2000-2006 Guus Sliepen 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., 675 Mass Ave, Cambridge, MA 02139, USA. $Id$ */ #include "system.h" #include "xalloc.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) { #ifdef HAVE_FORK 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; #else return -1; #endif } #endif #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 + 1); if(status > len - 1) { len = status; va_start(ap, fmt); status = vsnprintf(*buf, len, fmt, ap); va_end(ap); } return status; } #endif #ifndef HAVE_GETTIMEOFDAY int gettimeofday(struct timeval *tv, void *tz) { tv->tv_sec = time(NULL); tv->tv_usec = 0; return 0; } #endif #ifndef HAVE_RANDOM #include long int random(void) { long int x; RAND_pseudo_bytes((unsigned char *)&x, sizeof(x)); return x; } #endif