1SETRESUID(2) Linux Programmer's Manual SETRESUID(2)
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6 setresuid, setresgid - set real, effective and saved user or group ID
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9 #define _GNU_SOURCE
10 #include <unistd.h>
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12 int setresuid(uid_t ruid, uid_t euid, uid_t suid);
13 int setresgid(gid_t rgid, gid_t egid, gid_t sgid);
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16 setresuid() sets the real user ID, the effective user ID, and the saved
17 set-user-ID of the calling process.
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19 Unprivileged user processes may change the real UID, effective UID, and
20 saved set-user-ID, each to one of: the current real UID, the current
21 effective UID or the current saved set-user-ID.
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23 Privileged processes (on Linux, those having the CAP_SETUID capability)
24 may set the real UID, effective UID, and saved set-user-ID to arbitrary
25 values.
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27 If one of the arguments equals -1, the corresponding value is not
28 changed.
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30 Regardless of what changes are made to the real UID, effective UID, and
31 saved set-user-ID, the file system UID is always set to the same value
32 as the (possibly new) effective UID.
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34 Completely analogously, setresgid() sets the real GID, effective GID,
35 and saved set-group-ID of the calling process (and always modifies the
36 file system GID to be the same as the effective GID), with the same
37 restrictions for non-privileged processes.
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40 On success, zero is returned. On error, -1 is returned, and errno is
41 set appropriately.
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44 EAGAIN uid does not match the current UID and this call would bring
45 that user ID over its RLIMIT_NPROC resource limit.
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47 EPERM The calling process is not privileged (did not have the
48 CAP_SETUID capability) and tried to change the IDs to values
49 that are not permitted.
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52 These calls are available under Linux since Linux 2.1.44.
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55 These calls are non-standard; they also appear on HP-UX and some of the
56 BSDs.
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59 Under HP-UX and FreeBSD the prototype is found in <unistd.h>. Under
60 Linux the prototype is provided by glibc since version 2.3.2.
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63 getresuid(2), getuid(2), setfsgid(2), setfsuid(2), setreuid(2),
64 setuid(2), capabilities(7), credentials(7), feature_test_macros(7)
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67 This page is part of release 3.22 of the Linux man-pages project. A
68 description of the project, and information about reporting bugs, can
69 be found at http://www.kernel.org/doc/man-pages/.
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73Linux 2007-07-26 SETRESUID(2)