GETUID(3) Library Functions Manual GETUID(3)

getuid — get a real user ID

#include <unistd.h>

uid_t getuid(void);

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

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

No errors are defined.

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());
...

None.

None.

None.

getegid(3), geteuid(3), getgid(3), setegid(3), seteuid(3), setgid(3), setregid(3), setreuid(3), setuid(3), the Base Definitions volume of IEEE Std 1003.1-2001 (“POSIX.1”), <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:

  • 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.

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January 1, 2004 posix.fail