GETUID(2) |
FreeBSD System Calls Manual |
GETUID(2) |
NAME
getuid,
geteuid —
get user identification
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include < unistd.h>
#include < sys/types.h>
uid_t
getuid( void);
uid_t
geteuid( void);
DESCRIPTION
The
getuid() system call returns the real user ID of the calling process. The
geteuid() system call returns the effective user ID of the calling process.
The real user ID is that of the user who has invoked the program. As the effective user ID gives the process additional permissions during execution of “ set-user-ID” mode processes, getuid() is used to determine the real-user-id of the calling process.
ERRORS
The
getuid() and
geteuid() system calls are always successful, and no return value is reserved to indicate an error.
STANDARDS
The
geteuid() and
getuid() system calls are expected to conform to IEEE Std 1003.1-1990 (“POSIX.1”).
HISTORY
The
getuid() and
geteuid() functions appeared in Version 7 AT&T UNIX.