getsid - get session ID
#include <sys/types.h>
#include <unistd.h>
pid_t getsid(pid_t pid);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
getsid():
_XOPEN_SOURCE >= 500
|| /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L
returns the session ID of the calling process.
getsid()
returns the session ID of the process with process ID
pid. If
pid is 0,
getsid() returns the session ID of the calling
process.
On success, a session ID is returned. On error,
(pid_t) -1 will be
returned, and
errno is set appropriately.
- EPERM
- A process with process ID pid 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 pid was found.
This system call is available on Linux since version 2.0.
POSIX.1-2001, POSIX.1-2008, SVr4.
Linux does not return
EPERM.
See
credentials(7) for a description of sessions and session IDs.
getpgid(2),
setsid(2),
credentials(7)