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| NAME | LIBRARY | SYNOPSIS | DESCRIPTION | ERRORS | STANDARDS | HISTORY | SEE ALSO | COLOPHON | |
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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)
This page is part of the man-pages (Linux kernel and C library user-space interface documentation) project. Information about the project can be found at ⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report for this manual page, see ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩. This page was obtained from the tarball man-pages-6.10.tar.gz fetched from ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on 2025-02-02. If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up- to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which is not part of the original manual page), send a mail to man-pages@man7.org Linux man-pages 6.10 2024-07-23 getuid(2) Pages that refer to this page: groups(1@@shadow-utils), homectl(1), importctl(1), 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), systemd-vmspawn(1), timedatectl(1), updatectl(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)
| HTML rendering created 2025-02-02 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. | |