CUSERID(3)                OpenBSD Programmer's Manual               CUSERID(3)

NAME
     cuserid - get user name



SYNOPSIS
     #include <stdio.h>

     char *
     cuserid(char *buf);

DESCRIPTION
     This interface is available from the compatibility library, libcompat.

     The cuserid() function returns a character string representation of the
     user name associated with the effective user ID of the calling process.

     If buf is not the NULL pointer, the user name is copied into the memory
     referenced by buf. The argument buf is assumed to point to an array at
     least L_cuserid (as defined in the include file <stdio.h>) bytes long.
     Otherwise, the user name is copied to a static buffer.

RETURN VALUES
     If buf is not the NULL pointer, buf is returned; otherwise the address of
     the static buffer is returned.

     If the user name could not be determined, if buf is not the NULL pointer,
     the null character `\0' will be stored at *buf; otherwise the NULL point-
     er is returned.

SEE ALSO
     getlogin(2),  getpwent(3)

STANDARDS
     The cuserid() function conforms to IEEE Std1003.1-1988 (``POSIX'').

BUGS
     Due to irreconcilable differences in historic implementations, cuserid()
     was removed from the IEEE Std1003.1-1990 (``POSIX'') standard.  This im-
     plementation exists purely for compatibility with existing programs.  New
     programs should use one of the following three alternatives to obtain the
     user name:

           1.   getlogin() to return the user's login name.
           2.   getpwuid(geteuid()) to return the user name associated with
                the calling process' effective user ID.
           3.   getpwuid(getuid()) to return the user name associated with the
                calling process' real user ID.

     The cuserid() function uses getpwuid(); thus the results of a user's call
     to getpwent(), getpwnam() or getpwuid() will be overwritten by subsequent
     calls to cuserid().

OpenBSD 2.6                    November 28, 1993                             1