GUAC-1389: Document daemonization helper functions.

This commit is contained in:
Michael Jumper 2016-03-02 14:44:15 -08:00
parent cb8fe46328
commit 1e4a83b3da

View File

@ -53,7 +53,18 @@
/**
* Redirects the given file descriptor to /dev/null. The given flags must match
* the read/write flags of the file descriptor given.
* the read/write flags of the file descriptor given (if the given file
* descriptor was opened write-only, flags here must be O_WRONLY, etc.).
*
* @param fd
* The file descriptor to redirect to /dev/null.
*
* @param flags
* The flags to use when opening /dev/null as the target for redirection.
* These flags must match the flags of the file descriptor given.
*
* @return
* Zero on success, non-zero if redirecting the file descriptor fails.
*/
static int redirect_fd(int fd, int flags) {
@ -74,6 +85,17 @@ static int redirect_fd(int fd, int flags) {
/**
* Turns the current process into a daemon through a series of fork() calls.
* The standard I/O file desriptors for STDIN, STDOUT, and STDERR will be
* redirected to /dev/null, and the working directory is changed to root.
* Execution within the caller of this function will terminate before this
* function returns, while execution within the daemonized child process will
* continue.
*
* @return
* Zero if the daemonization process succeeded and we are now in the
* daemonized child process, or non-zero if daemonization failed and we are
* still the original caller. This function does not return for the original
* caller if daemonization succeeds.
*/
static int daemonize() {