getuid - get a real user ID
The getuid() function shall return the real user ID of the calling process. The getuid() function shall not modify errno.
The getuid() function shall always be successful and no return value is reserved to indicate the error.
No errors are defined.
Setting the Effective User ID to the Real User ID
The following example sets the effective user ID of the calling process to the real user ID.#include <unistd.h> ... seteuid(getuid());
In a conforming environment, getuid() will always succeed. It is possible for implementations to provide an extension where a process in a non-conforming environment will not be associated with a user or group ID. It is recommended that such implementations return (uid_t)-1 and set errno to indicate such an environment; doing so does not violate this standard, since such an environment is already an extension.
getegid, geteuid, getgid, setegid, seteuid, setgid, setregid, setreuid, setuid
XBD <sys/types.h>, <unistd.h>
First released in Issue 1. Derived from Issue 1 of the SVID.
In the SYNOPSIS, the optional include of the <sys/types.h> header is removed.
The following new requirements on POSIX implementations derive from alignment with the Single UNIX Specification:
POSIX.1-2008, Technical Corrigendum 2, XSH/TC2-2008/0175  and XSH/TC2-2008/0176  are applied.
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