GETSID(2)

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
        || /* 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
POSIX.1-2001, POSIX.1-2008, SVr4.

NOTES
Linux does not return EPERM.

SEE ALSO
getpgid(2), setsid(2), credentials(7)

COLOPHON
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