1GETRESUID(2) Linux Programmer's Manual GETRESUID(2)
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6 getresuid, getresgid - get real, effective and saved user/group IDs
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9 #define _GNU_SOURCE /* See feature_test_macros(7) */
10 #include <unistd.h>
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12 int getresuid(uid_t *ruid, uid_t *euid, uid_t *suid);
13 int getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid);
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16 getresuid() returns the real UID, the effective UID, and the saved set-
17 user-ID of the calling process, in the arguments ruid, euid, and suid,
18 respectively. getresgid() performs the analogous task for the
19 process's group IDs.
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22 On success, zero is returned. On error, -1 is returned, and errno is
23 set appropriately.
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26 EFAULT One of the arguments specified an address outside the calling
27 program's address space.
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30 These system calls appeared on Linux starting with kernel 2.1.44.
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32 The prototypes are given by glibc since version 2.3.2, provided
33 _GNU_SOURCE is defined.
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36 These calls are nonstandard; they also appear on HP-UX and some of the
37 BSDs.
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40 The original Linux getresuid() and getresgid() system calls supported
41 only 16-bit user and group IDs. Subsequently, Linux 2.4 added getre‐
42 suid32() and getresgid32(), supporting 32-bit IDs. The glibc getre‐
43 suid() and getresgid() wrapper functions transparently deal with the
44 variations across kernel versions.
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47 getuid(2), setresuid(2), setreuid(2), setuid(2), credentials(7)
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50 This page is part of release 5.10 of the Linux man-pages project. A
51 description of the project, information about reporting bugs, and the
52 latest version of this page, can be found at
53 https://www.kernel.org/doc/man-pages/.
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57Linux 2017-09-15 GETRESUID(2)