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()
   returns the session ID of the process with process ID pid.  If  pid  is
   0, getsid() returns the session ID of the calling process.

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 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.

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 credentials(7) for a description of sessions and session IDs.

SEE ALSO

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

COLOPHON

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