NAME

getuid - get a real user ID

SYNOPSIS

#include <unistd.h>

uid_t getuid(void);


DESCRIPTION

The getuid() function shall return the real user ID of the calling process.

RETURN VALUE

The getuid() function shall always be successful and no return value is reserved to indicate the error.

ERRORS

No errors are defined.

EXAMPLES

Setting the Effective User ID to the Real User ID

The following example sets the effective user ID and the real user ID of the current process to the real user ID of the caller.

#include <unistd.h>
#include <sys/types.h>
...
setreuid(getuid(), getuid());
...

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

getegid(), geteuid(), getgid(), setegid(), seteuid(), setgid(), setregid(), setreuid(), setuid(), the Base Definitions volume of IEEE Std 1003.1-2001, <sys/types.h>, <unistd.h>

CHANGE HISTORY

First released in Issue 1. Derived from Issue 1 of the SVID.

Issue 6

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:

• The requirement to include <sys/types.h> has been removed. Although <sys/types.h> was required for conforming implementations of previous POSIX specifications, it was not required for UNIX applications.