LDP
/
man-pages
mirror of https://github.com/mkerrisk/man-pages
0
1
Fork 0
Code Releases Activity

pidfd_open.2: Explain how pidfd_open() can be used to with fork() 

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This commit is contained in:
Michael Kerrisk 2019-09-25 15:23:18 +02:00
parent 6059228b26
commit 59341b5269
1 changed files with 21 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
man2/pidfd_open.2
View File

@ -91,6 +91,27 @@ is Linux specific.
Currently, there is no glibc wrapper for this system call; call it using
.BR syscall (2).
.PP
The following code sequence can be used to obtain a file descriptor
for the child of
.BR fork (2):
.PP
.in +4n
.EX
pid = fork();
if (pid > 0) { /* If parent */
pidfd = pidfd_open(pid, 0);
...
}
.EE
.in
.PP
Even if the child process has already terminated by the time of the
.BR pidfd_open ()
call, the returned file descriptor
is guaranteed to refer to the child because
the parent has not yet waited on the child
(and therefore, the child's ID has not been recycled).
.PP
The
.BR pidfd_send_signal (2)
system call can be used to send a signal to the process referred to by