getuid (2)

NAME

getuid, geteuid - get user identity

SYNOPSIS

#include <unistd.h>
 
#include <sys/types.h>
uid_t getuid(void);
 
uid_t geteuid(void);

DESCRIPTION

getuid() returns the real user ID of the calling process.
geteuid() returns the effective user ID of the calling process.

ERRORS

These functions are always successful.

CONFORMING TO

POSIX.1-2001, POSIX.1-2008, 4.3BSD.

NOTES

History

In UNIX V6 the getuid() call returned (euid << 8) + uid. UNIX V7 introduced separate calls getuid() and geteuid().
The original Linux getuid() and geteuid() system calls supported only 16-bit user IDs. Subsequently, Linux 2.4 added getuid32() and geteuid32(), supporting 32-bit IDs. The glibc getuid() and geteuid() wrapper functions transparently deal with the variations across kernel versions.

SEE ALSO

getresuid(2), setreuid(2), setuid(2), credentials(7)

Information

Source
Linux kernel
OS/version
Linux
Source updated
September 15, 2017
Page created
February 9, 2018
Page generated
December 2, 2018