getresuid(2)

1getresuid(2)                  System Calls Manual                 getresuid(2)
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NAME

6       getresuid, getresgid - get real, effective, and saved user/group IDs
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LIBRARY

9       Standard C library (libc, -lc)
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SYNOPSIS

12       #define _GNU_SOURCE         /* See feature_test_macros(7) */
13       #include <unistd.h>
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15       int getresuid(uid_t *ruid, uid_t *euid, uid_t *suid);
16       int getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid);
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DESCRIPTION

19       getresuid() returns the real UID, the effective UID, and the saved set-
20       user-ID of the calling process, in the arguments ruid, euid, and  suid,
21       respectively.    getresgid()   performs  the  analogous  task  for  the
22       process's group IDs.
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RETURN VALUE

25       On success, zero is returned.  On error, -1 is returned, and  errno  is
26       set to indicate the error.
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ERRORS

29       EFAULT One  of  the  arguments specified an address outside the calling
30              program's address space.
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STANDARDS

33       None.  These calls also appear on HP-UX and some of the BSDs.
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HISTORY

36       Linux 2.1.44, glibc 2.3.2.
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38       The original Linux getresuid() and getresgid() system  calls  supported
39       only  16-bit  user and group IDs.  Subsequently, Linux 2.4 added getre‐
40       suid32() and getresgid32(), supporting 32-bit IDs.   The  glibc  getre‐
41       suid()  and  getresgid()  wrapper functions transparently deal with the
42       variations across kernel versions.
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