getpid(2) getpid(2)
NAME
getpid, getpgrp, getppid, getpgid, BSDgetpgrp - get process, process
group, and parent process IDs
SYNOPSIS
#include <sys/types.h>
#include <unistd.h>
pidt getpid(void);
pidt getpgrp(void);
pidt getppid(void);
pidt getpgid(pidt pid);
pidt BSDgetpgrp(pidt pid);
DESCRIPTION
getpid returns the process ID of the calling process.
getpgrp returns the process group ID of the calling process. The
BSDgetpgrp form is provided for Berkeley compatiblity. If the pid_t is
0, it is the same as the getpgrp form, otherwise it returns the process
group for the argument, if the process exists.
getppid returns the parent process ID of the calling process.
getpgid returns the process group ID of the process whose process ID is
equal to pid, or the process group ID of the calling process, if pid is
equal to zero.
getpgid will fail if one or more of the following is true:
EPERM The process whose process ID is equal to pid is not in the
same session as the calling process, and the
implementation does not allow access to the process group
ID of that process from the calling process.
ESRCH There is no process with a process ID equal to pid.
SEE ALSO
exec(2), fork(2), getpid(2), getsid(2), intro(2), setpgid(2), setsid(2)
setpgrp(2), signal(2).
DIAGNOSTICS
Upon successful completion, getpgid returns a process group ID.
Otherwise, a value of (pidt) -1 is returned and errno is set to indicate
the error.
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