projects / thirdparty / man-pages.git / blame
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|---|---|---|
| fea681da MK |
1 | .\" Copyright 1993 Rickard E. Faith (faith@cs.unc.edu) |
| 2 | .\" | |
| 5fbde956 | 3 | .\" SPDX-License-Identifier: Linux-man-pages-copyleft |
| fea681da MK |
4 | .\" |
| 5 | .\" Historical remark, aeb, 2004-06-05 | |
| ab47278f | 6 | .TH GETUID 2 (date) "Linux man-pages (unreleased)" |
| fea681da MK |
7 | .SH NAME |
| 8 | getuid, geteuid \- get user identity | |
| d1c2f5d3 AC |
9 | .SH LIBRARY |
| 10 | Standard C library | |
| 8fc3b2cf | 11 | .RI ( libc ", " \-lc ) |
| fea681da | 12 | .SH SYNOPSIS |
| c7db92b9 | 13 | .nf |
| fea681da | 14 | .B #include <unistd.h> |
| 68e4db0a | 15 | .PP |
| fea681da | 16 | .B uid_t getuid(void); |
| fea681da | 17 | .B uid_t geteuid(void); |
| c7db92b9 | 18 | .fi |
| fea681da | 19 | .SH DESCRIPTION |
| e511ffb6 | 20 | .BR getuid () |
| a1ffe9f5 | 21 | returns the real user ID of the calling process. |
| efeece04 | 22 | .PP |
| e511ffb6 | 23 | .BR geteuid () |
| a1ffe9f5 | 24 | returns the effective user ID of the calling process. |
| fea681da | 25 | .SH ERRORS |
| b926779b MK |
26 | These functions are always successful |
| 27 | and never modify | |
| 28 | .\" https://www.austingroupbugs.net/view.php?id=511 | |
| 29 | .\" 0000511: getuid and friends should not modify errno | |
| 30 | .IR errno . | |
| 3113c7f3 | 31 | .SH STANDARDS |
| 03e52a0a | 32 | POSIX.1-2001, POSIX.1-2008, 4.3BSD. |
| 889829be MK |
33 | .SH NOTES |
| 34 | .SS History | |
| b4112efb | 35 | In UNIX\ V6 the |
| 60a90ecd | 36 | .BR getuid () |
| 4f9f83f0 MK |
37 | call returned |
| 38 | .IR "(euid << 8) + uid" . | |
| b4112efb | 39 | UNIX\ V7 introduced separate calls |
| 60a90ecd MK |
40 | .BR getuid () |
| 41 | and | |
| 42 | .BR geteuid (). | |
| efeece04 | 43 | .PP |
| 80978cba MK |
44 | The original Linux |
| 45 | .BR getuid () | |
| 46 | and | |
| 47 | .BR geteuid () | |
| 48 | system calls supported only 16-bit user IDs. | |
| c5662d5d | 49 | Subsequently, Linux 2.4 added |
| 80978cba MK |
50 | .BR getuid32 () |
| 51 | and | |
| 52 | .BR geteuid32 (), | |
| 53 | supporting 32-bit IDs. | |
| 54 | The glibc | |
| 55 | .BR getuid () | |
| 56 | and | |
| 57 | .BR geteuid () | |
| 58 | wrapper functions transparently deal with the variations across kernel versions. | |
| 70ea1968 | 59 | .PP |
| 03936fb4 | 60 | On Alpha, instead of a pair of |
| b30b425b MK |
61 | .BR getuid () |
| 62 | and | |
| 63 | .BR geteuid () | |
| 03936fb4 | 64 | system calls, a single |
| 70ea1968 ES |
65 | .BR getxuid () |
| 66 | system call is provided, which returns a pair of real and effective UIDs. | |
| 67 | The glibc | |
| 68 | .BR getuid () | |
| 69 | and | |
| 70 | .BR geteuid () | |
| 71 | wrapper functions transparently deal with this. | |
| 72 | See | |
| 73 | .BR syscall (2) | |
| 74 | for details regarding register mapping. | |
| 47297adb | 75 | .SH SEE ALSO |
| 520b53c6 | 76 | .BR getresuid (2), |
| fea681da | 77 | .BR setreuid (2), |
| 520b53c6 MK |
78 | .BR setuid (2), |
| 79 | .BR credentials (7) |