getuid(2) [freebsd man page]

GETUID(2)						      BSD System Calls Manual							 GETUID(2)

NAME

     getuid, geteuid -- get user identification

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <unistd.h>
     #include <sys/types.h>

     uid_t
     getuid(void);

     uid_t
     geteuid(void);

DESCRIPTION

     The getuid() system call returns the real user ID of the calling process.	The geteuid() system call returns the effective user ID of the
     calling process.

     The real user ID is that of the user who has invoked the program.	As the effective user ID gives the process additional permissions during
     execution of ``set-user-ID'' mode processes, getuid() is used to determine the real-user-id of the calling process.

ERRORS

     The getuid() and geteuid() system calls are always successful, and no return value is reserved to indicate an error.

SEE ALSO

     getgid(2), issetugid(2), setgid(2), setreuid(2), setuid(2)

STANDARDS

     The geteuid() and getuid() system calls are expected to conform to ISO/IEC 9945-1:1990 (``POSIX.1'').

HISTORY

     The getuid() and geteuid() functions appeared in Version 7 AT&T UNIX.

BSD
								   June 4, 1993 							       BSD

GETUID(2)						     Linux Programmer's Manual							 GETUID(2)

NAME

       getuid, geteuid - get user identity

SYNOPSIS

       #include <unistd.h>
       #include <sys/types.h>

       uid_t getuid(void);
       uid_t geteuid(void);

DESCRIPTION

       getuid() returns the real user ID of the calling process.

       geteuid() returns the effective user ID of the calling process.

ERRORS

       These functions are always successful.

CONFORMING TO

       POSIX.1-2001, 4.3BSD.

NOTES

   History
       In UNIX V6 the getuid() call returned (euid << 8) + uid.  UNIX V7 introduced separate calls getuid() and geteuid().

       The  original  Linux  getuid()  and  geteuid()  system  calls supported only 16-bit user IDs.  Subsequently, Linux 2.4 added getuid32() and
       geteuid32(), supporting 32-bit IDs.  The glibc getuid() and geteuid() wrapper functions transparently deal with the variations across  ker-
       nel versions.

SEE ALSO

       getresuid(2), setreuid(2), setuid(2), credentials(7)

COLOPHON

       This  page is part of release 3.53 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2010-11-22								 GETUID(2)