getsid(2) - Linux man page
Name
getsid - get session ID
Synopsis
#include <unistd.h>
pid_t getsid(pid_t pid);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
- getsid():
- _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
|| /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L
Description
getsid(0) returns the session ID of the calling process. getsid(p) returns the session ID of the process with process ID p. (The session ID of a process is the process group ID of the session leader.)
Return Value
On success, a session ID is returned. On error, (pid_t) -1 will be returned, and errno is set appropriately.
Errors
- EPERM
A process with process ID p exists, but it is not in the same session as the calling process, and the implementation considers this an error.
ESRCH
No process with process ID p was found.
Versions
This system call is available on Linux since version 2.0.
Conforming To
SVr4, POSIX.1-2001.
Notes
Linux does not return EPERM.
See Also
getpgid(2), setsid(2), credentials(7)