SETPGID(2)                FreeBSD System Calls Manual               SETPGID(2)

NAME
     setpgid, setpgrp - set process group

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     int
     setpgid(pid_t pid, pid_t pgrp);

     int
     setpgrp(pid_t pid, pid_t pgrp);

DESCRIPTION
     The setpgid() system call sets the process group of the specified process
     pid to the specified pgrp.  If pid is zero, then the call applies to the
     current process.  If pgrp is zero, then the process id of the process
     specified by pid is used instead.

     If the affected process is not the invoking process, then it must be a
     child of the invoking process, it must not have performed an exec(3)
     operation, and both processes must be in the same session.  The requested
     process group ID must already exist in the session of the caller, or it
     must be equal to the target process ID.

RETURN VALUES
     The setpgid() function returns the value 0 if successful; otherwise the
     value -1 is returned and the global variable errno is set to indicate the
     error.

COMPATIBILITY
     The setpgrp() system call is identical to setpgid(), and is retained for
     calling convention compatibility with historical versions of BSD.

ERRORS
     The setpgid() system call will fail and the process group will not be
     altered if:

     [EINVAL]           The requested process group ID is not legal.

     [ESRCH]            The requested process does not exist.

     [ESRCH]            The target process is not the calling process or a
                        child of the calling process.

     [EACCES]           The requested process is a child of the calling
                        process, but it has performed an exec(3) operation.

     [EPERM]            The target process is a session leader.

     [EPERM]            The requested process group ID is not in the session
                        of the caller, and it is not equal to the process ID
                        of the target process.

SEE ALSO
     getpgrp(2)

STANDARDS
     The setpgid() system call is expected to conform to IEEE Std 1003.1-1990
     ("POSIX.1").

FreeBSD 13.1-RELEASE-p6        February 8, 2004        FreeBSD 13.1-RELEASE-p6