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Diffstat (limited to 'src/unistd.rs')
| -rw-r--r-- | src/unistd.rs | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/src/unistd.rs b/src/unistd.rs index e37482a5..bcc09150 100644 --- a/src/unistd.rs +++ b/src/unistd.rs @@ -411,6 +411,40 @@ pub fn execvp(filename: &CString, args: &[CString]) -> Result<Void> { Err(Error::Sys(Errno::last())) } +/// Daemonize this process by detaching from the controlling terminal (see +/// [daemon(3)](http://man7.org/linux/man-pages/man3/daemon.3.html)). +/// +/// When a process is launched it is typically associated with a parent and it, +/// in turn, by its controlling terminal/process. In order for a process to run +/// in the "background" it must daemonize itself by detaching itself. Under +/// posix, this is done by doing the following: +/// +/// 1. Parent process (this one) forks +/// 2. Parent process exits +/// 3. Child process continues to run. +/// +/// There are a couple options here whose names and meaning can be a bit +/// confusing, so we'll describe the behavior for each state. +/// +/// For `nochdir`: +/// +/// * `nochdir = true`: The current working directory after daemonizing will +/// be the current working directory. +/// * `nochdir = false`: The current working directory after daemonizing will +/// be the root direcory, `/`. +/// +/// For `noclose`: +/// +/// * `noclose = true`: The process' current stdin, stdout, and stderr file +/// descriptors will remain identical after daemonizing. +/// * `noclose = false`: The process' stdin, stdout, and stderr will point to +/// `/dev/null` after daemonizing. +/// +/// The underlying implementation (in libc) calls both +/// [fork(2)](http://man7.org/linux/man-pages/man2/fork.2.html) and +/// [setsid(2)](http://man7.org/linux/man-pages/man2/setsid.2.html) and, as +/// such, error that could be returned by either of those functions could also +/// show up as errors here. pub fn daemon(nochdir: bool, noclose: bool) -> Result<()> { let res = unsafe { libc::daemon(nochdir as c_int, noclose as c_int) }; Errno::result(res).map(drop) |