getpid(2) SDK R4.11 getpid(2)
NAME
getpid, getpgrp, getppid, getpgid - get process, process group, and
parent process IDs
SYNOPSIS
#include <sys/types.h>
#include <unistd.h>
pid_t getpid(void);
pid_t getpgrp(void);
pid_t getppid(void);
pid_t getpgid(pid_t pid);
DESCRIPTION
getpid returns the process ID of the calling process.
getpgrp returns the process group ID of the calling process.
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.
RETURN VALUE
getpid, getpgrp, and getppid return the values given above.
Upon successful completion, getpgid returns a process group ID.
Otherwise, a value of (pid_t) -1 is returned and errno is set to
indicate the error.
DIAGNOSTICS
getpid, getpgrp, and getppid always succeed.
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).
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