setresuid, setresgid — set real, effective and saved user or group ID
#define _GNU_SOURCE #include <unistd.h>
int
setresuid( |
uid_t | ruid, |
uid_t | euid, | |
uid_t | suid) ; |
int
setresgid( |
gid_t | rgid, |
gid_t | egid, | |
gid_t | sgid) ; |
setresuid
() sets the real
user ID, the effective user ID, and the saved set-user-ID of
the current process.
Unprivileged user processes may change the real UID, effective UID, and saved set-user-ID, each to one of: the current real UID, the current effective UID or the current saved set-user-ID.
Privileged processes (on Linux, those having the CAP_SETUID capability) may set the real UID, effective UID, and saved set-user-ID to arbitrary values.
If one of the parameters equals −1, the corresponding value is not changed.
Regardless of what changes are made to the real UID, effective UID, and saved set-user-ID, the file system UID is always set to the same value as the (possibly new) effective UID.
Completely analogously, setresgid
() sets the real GID, effective
GID, and saved set-group-ID of the current process (and
always modifies the file system GID to be the same as the
effective GID), with the same restrictions for non-privileged
processes.
On success, zero is returned. On error, −1 is
returned, and errno
is set
appropriately.
uid
does
not match the current UID and this call would bring
that user ID over its NPROC rlimit.
The calling process is not privileged (did not have the CAP_SETUID capability) and tried to change the IDs to values that are not permitted.
Under HP-UX and FreeBSD the prototype is found in
<unistd.h>
.
Under Linux the prototype is given by glibc since version
2.3.2 provided _GNU_SOURCE is defined.
getresuid(2), getuid(2), setfsuid(2), setfsgid(2), setreuid(2), setuid(2), capabilities(7), feature_test_macros(7)
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