getuid

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.

When a normal program is executed, the effective and real user ID of the process are set to the ID of the user executing the file. When a set ID program is executed the real user ID is set to the calling user and the effective user ID corresponds to the set ID bit on the file being executed.

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().

SEE ALSO

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

COLOPHON

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