cuserid(S)                     6 January 1993                     cuserid(S)


 Name

    cuserid - get character login name of the user

 Syntax


    cc  . . .  -lc


    #include  <stdio.h>

    char *cuserid (s)
    char *s;


 Description

    The cuserid routine creates a character-string of the login name that the
    owner of the current process is logged in under.  If s is a NULL pointer,
    this string is generated in an internal static area, the address of which
    is returned by cuserid. Otherwise, the string is left in the array,
    assumed to contain at least Lcuserid characters, to which s points.  The
    constant Lcuserid is defined in the <stdio.h> header file.

 Return value

    If the argument s is not NULL and the routine is successful, cuserid
    returns s.  If s is NULL, the routine returns the address where the
    string is internally stored.  If the login name is not found and s is
    NULL, cuserid returns a NULL pointer. If the login name is not found and
    s is not NULL, a null character('\0') will be placed in s[0] and s is
    returned by cuserid.

 Note

    When s is NULL, as mentioned above, the string is stored in an internal
    static area whose contents are overwritten by each call to cuserid.

    The cuserid routine uses the getpwuid routine, and therefore the results
    of a getpwuid or a getpwnam routine may be destroyed by a subsequent call
    to cuserid.

 See also

    getlogin(S), getpwent(S)

 Standards conformance

    cuserid conforms with:
    X/Open Portability Guide, Issue 3, 1989;
    IEEE POSIX Std 1003.1-1990 System Application Program Interface (API) [C
    Language] (ISO/IEC 9945-1);
    and NIST FIPS 151-1.