NAME | LIBRARY | SYNOPSIS | DESCRIPTION | ERRORS | STANDARDS | HISTORY | SEE ALSO |
|
|
getuid(2) System Calls Manual getuid(2)
getuid, geteuid - get user identity
Standard C library (libc, -lc)
#include <unistd.h> uid_t getuid(void); uid_t geteuid(void);
getuid() returns the real user ID of the calling process. geteuid() returns the effective user ID of the calling process.
These functions are always successful and never modify errno.
POSIX.1-2008.
POSIX.1-2001, 4.3BSD. 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. On Alpha, instead of a pair of getuid() and geteuid() system calls, a single getxuid() system call is provided, which returns a pair of real and effective UIDs. The glibc getuid() and geteuid() wrapper functions transparently deal with this. See syscall(2) for details regarding register mapping.
getresuid(2), setreuid(2), setuid(2), credentials(7)
Linux man-pages 6.04 2023-03-30 getuid(2)
Pages that refer to this page: groups(1@@shadow-utils), journalctl(1), localectl(1), loginctl(1), machinectl(1), portablectl(1), ps(1), strace(1), systemctl(1), systemd(1), systemd-analyze(1), systemd-inhibit(1), systemd-nspawn(1), timedatectl(1), userdbctl(1), getresuid(2), seteuid(2), setpgid(2), setresuid(2), setreuid(2), setuid(2), syscalls(2), getlogin(3), id_t(3type), pam_close_session(3), pam_open_session(3), sysexits.h(3head), credentials(7), signal-safety(7), user_namespaces(7), systemd-tmpfiles(8)