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, 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)

COLOPHON
This page is part of release 3.50 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.