setpgid(2)                                                          setpgid(2)


NAME
     setpgid - set process group ID

SYNOPSIS
     #include <sys/types.h>
     #include <unistd.h>

     int setpgid(pid_t pid, pid_t pgid);

DESCRIPTION
     setpgid sets the process group ID of the process with ID pid to pgid.  If
     pgid is equal to pid,  the process becomes a process group leader.  If
     pgid is not equal to pid, the process becomes a member of an existing
     process group.

     If pid is equal to 0, the process ID of the calling process is used.  If
     pgid is equal to 0, the process specified by pid becomes a process group
     leader.

     setpgid fails and returns an error if one or more of the following are
     true:

     EACCES         pid matches the process ID of a child process of the
                    calling process and the child process has successfully
                    executed an exec(2) function.

     EACCES         In the Trusted IRIX environment, the Mandatory Access
                    Control (MAC) label of the calling process is not equal to
                    the MAC label of pid and the calling process does not have
                    the CAP_MAC_READ and CAP_MAC_WRITE capabilities(4).

     EINVAL         pgid is not a valid process group id value.

     EINVAL         The calling process has a controlling terminal that does
                    not support job control.

     EPERM          The process indicated by the pid argument is a session
                    leader.

     EPERM          pid matches the process ID of a child process of the
                    calling process and the child process is not in the same
                    session as the calling process.

     EPERM          pgid does not match the process ID of the process
                    indicated by the pid argument and there is no process with
                    a process group ID that matches pgid in the same session
                    as the calling process.

     ESRCH          pid does not match the process ID of the calling process
                    or of a child process of the calling process.


SEE ALSO
     exec(2), exit(2), fork(2), getpid(2), getpgid(2), setsid(2),
     tcsetpgrp(3T).  capabilities(4).  dominance(5).

DIAGNOSTICS
     Upon successful completion, setpgid returns a value of 0.  Otherwise, a
     value of -1 is returned and errno is set to indicate the error.


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