setpgrp(2) [freebsd man page]

SETPGID(2)						      BSD 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 ISO/IEC 9945-1:1990 (``POSIX.1'').

BSD
								 February 8, 2004							       BSD

setpgid(3)						     Library Functions Manual							setpgid(3)

Name
       setpgid - set process group (POSIX)

Syntax
       #include <sys/types.h>
       int
       setpgid(pid, pgrp)
       pid_t pid, pgrp;

Description
       The  function is used to either join an existing process group or create a new process group within the session of the calling process (see
       Upon successful completion, the process group ID of the process that has a process ID which matches pid is set to pgrp.	If  pid  is  zero,
       then the call applies to the current process. In addition, if pgrp is zero, the process ID of the indicated process is used.

       This function is available only in the POSIX environment.

Return Values
       The  function  returns 0 when the operation is successful.  If the request fails, -1 is returned and the global variable indicates the rea-
       son.

Diagnostics
       The function fails and the process group is not altered if one of the following occurs:

       [EACCES]       The value of the pid argument matches the process ID of a child process of the calling process and  the  child  process  has
		      successfully executed an function.

       [EINVAL]       The value of the pgrp argument is less than zero or is not a supported value.

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

		      The  value of the pid argument 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.

		      The value of the pgrp argument 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 the value of the pgrp argument in the same session as the calling process.

       [ESRCH]	      The  value  of  the  pid	argument  does	not  match the process ID of the calling process of a child process of the calling
		      process.

See Also
       getpgrp(2), setsid(2)

																	setpgid(3)