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

       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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