getpid(2) System Calls getpid(2)NAME
getpid, getpgrp, getppid, getpgid - get process, process group, and
parent process IDs
SYNOPSIS
#include <unistd.h>
pid_t getpid(void);
pid_t getpgrp(void);
pid_t getppid(void);
pid_t getpgid(pid_t pid);
DESCRIPTION
The getpid() function returns the process ID of the calling process.
The getpgrp() function returns the process group ID of the calling
process.
The getppid() function returns the parent process ID of the calling
process.
The getpgid() function returns the process group ID of the process
whose process ID is equal to pid, or the process group ID of the call‐
ing process, if pid is equal to 0.
RETURN VALUES
Upon successful completion, these functions return the process group
ID. Otherwise, getpgid() returns (pid_t)−1 and sets errno to indicate
the error.
ERRORS
The getpgid() function will fail if:
EPERM The process whose process ID is equal to pid is not in
the same session as the calling process, and the imple‐
mentation 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.
The getpgid() function may fail if:
EINVAL The value of the pid argument is invalid.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Standard │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │Async-Signal-Safe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOintro(2), exec(2), fork(2), getsid(2), setpgid(2), setpgrp(2), setsid
(2), signal(3C), attributes(5), standards(5)SunOS 5.10 28 Dec 1996 getpid(2)
