GETSID(3) Library Functions Manual GETSID(3)

NAME

getsid — get the process group ID of a session leader

SYNOPSIS

#include <unistd.h>

pid_t getsid(pid_t pid);

DESCRIPTION

The getsid () function shall obtain the process group ID of the process that is the session leader of the process specified by pid. If pid is ( pid_t) 0, it specifies the calling process.

RETURN VALUE

Upon successful completion, getsid () shall return the process group ID of the session leader of the specified process. Otherwise, it shall return -1 and set errno to indicate the error.

ERRORS

The getsid () function shall fail if:

[EPERM]: The process specified by pid is not in the same session as the calling process, and the implementation does not allow access to the process group ID of the session leader of that process from the calling process.
[ESRCH]: There is no process with a process ID equal to pid .

The following sections are informative.