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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.