id_t(3type)

NAME
pid_t, uid_t, gid_t, id_t - process/user/group identifier

LIBRARY
Standard C library (libc)

SYNOPSIS
#include <sys/types.h>

typedef /* ... */ pid_t;
typedef /* ... */ uid_t;
typedef /* ... */ gid_t;
typedef /* ... */ id_t;

DESCRIPTION
pid_t is a type used for storing process IDs, process group IDs, and session IDs. It is a signed integer type.

uid_t is a type used to hold user IDs. It is an integer type.

gid_t is a type used to hold group IDs. It is an integer type.

id_t is a type used to hold a general identifier. It is an integer type that can be used to contain a pid_t, uid_t, or gid_t.

STANDARDS
POSIX.1-2024.

HISTORY
POSIX.1-2001.

NOTES
The following headers also provide pid_t: <fcntl.h>, <sched.h>, <signal.h>, <spawn.h>, <sys/msg.h>, <sys/sem.h>, <sys/shm.h>, <sys/wait.h>, <termios.h>, <time.h>, <unistd.h>, and <utmpx.h>.

The following headers also provide uid_t: <pwd.h>, <signal.h>, <stropts.h>, <sys/ipc.h>, <sys/stat.h>, and <unistd.h>.

The following headers also provide gid_t: <grp.h>, <pwd.h>, <signal.h>, <stropts.h>, <sys/ipc.h>, <sys/stat.h>, and <unistd.h>.

The following header also provides id_t: <sys/resource.h>.

SEE ALSO
chown(2), fork(2), getegid(2), geteuid(2), getgid(2), getgroups(2), getpgid(2), getpid(2), getppid(2), getpriority(2), getpwnam(3), getresgid(2), getresuid(2), getsid(2), gettid(2), getuid(2), kill(2), pidfd_open(2), sched_setscheduler(2), waitid(2), getgrnam(3), sigqueue(3), credentials(7)