getuid3p
Get a real user id
Usage
#include <unistd.h>
uid_t getuid(void);
Prolog
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.
Overview
The getuid() function shall return the real user ID of the calling process. The getuid() function shall not modify errno.
Return value
The getuid() function shall always be successful and no return value is reserved to indicate the error.
Errors
No errors are defined.
The following sections are informative.
Examples
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());
Application usage
None.
Rationale
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.
Future directions
None.