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. 

EINVAL pgid is less than (pid_t) 0, or greater than or equal to {PID_MAX}. 

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)

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.