daemon(3) [debian man page]

DAEMON(3)						     Linux Programmer's Manual							 DAEMON(3)

NAME

       daemon - run in the background

SYNOPSIS

       #include <unistd.h>

       int daemon(int nochdir, int noclose);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       daemon(): _BSD_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500)

DESCRIPTION

       The  daemon()  function is for programs wishing to detach themselves from the controlling terminal and run in the background as system dae-
       mons.

       If nochdir is zero, daemon() changes the calling process's current working directory to the root directory ("/");  otherwise,  the  current
       working directory is left unchanged.

       If  noclose  is zero, daemon() redirects standard input, standard output and standard error to /dev/null; otherwise, no changes are made to
       these file descriptors.

RETURN VALUE

       (This function forks, and if the fork(2) succeeds, the parent calls _exit(2), so that further errors are seen by the child only.)  On  suc-
       cess daemon() returns zero.  If an error occurs, daemon() returns -1 and sets errno to any of the errors specified for the fork(2) and set-
       sid(2).

CONFORMING TO

       Not in POSIX.1-2001.  A similar function appears on the BSDs.  The daemon() function first appeared in 4.4BSD.

NOTES

       The glibc implementation can also return -1 when /dev/null exists but is not a character device with the expected major and minor  numbers.
       In this case errno need not be set.

SEE ALSO

       fork(2), setsid(2)

COLOPHON

       This  page is part of release 3.44 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

GNU
								    2009-12-05								 DAEMON(3)

CHDIR(2)						     Linux Programmer's Manual							  CHDIR(2)

NAME

       chdir, fchdir - change working directory

SYNOPSIS

       #include <unistd.h>

       int chdir(const char *path);
       int fchdir(int fd);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       fchdir():
	   Since glibc 2.12:
	       _BSD_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED || _POSIX_C_SOURCE >= 200809L
	   Before glibc 2.12:
	       _BSD_SOURCE || _XOPEN_SOURCE >= 500 _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED

DESCRIPTION

       chdir() changes the current working directory of the calling process to the directory specified in path.

       fchdir() is identical to chdir(); the only difference is that the directory is given as an open file descriptor.

RETURN VALUE

       On success, zero is returned.  On error, -1 is returned, and errno is set appropriately.

ERRORS

       Depending on the file system, other errors can be returned.  The more general errors for chdir() are listed below:

       EACCES Search permission is denied for one of the components of path.  (See also path_resolution(7).)

       EFAULT path points outside your accessible address space.

       EIO    An I/O error occurred.

       ELOOP  Too many symbolic links were encountered in resolving path.

       ENAMETOOLONG
	      path is too long.

       ENOENT The file does not exist.

       ENOMEM Insufficient kernel memory was available.

       ENOTDIR
	      A component of path is not a directory.

       The general errors for fchdir() are listed below:

       EACCES Search permission was denied on the directory open on fd.

       EBADF  fd is not a valid file descriptor.

CONFORMING TO

       SVr4, 4.4BSD, POSIX.1-2001.

NOTES

       The current working directory is the starting point for interpreting relative pathnames (those not starting with '/').

       A  child  process  created via fork(2) inherits its parent's current working directory.	The current working directory is left unchanged by
       execve(2).

       The prototype for fchdir() is only available if _BSD_SOURCE is defined, or _XOPEN_SOURCE is defined with the value 500.

SEE ALSO

       chroot(2), getcwd(3), path_resolution(7)

COLOPHON

       This page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2010-09-20								  CHDIR(2)