NAME
    isfile - whether a value is a file

SYNOPSIS
    isfile(x)

TYPES
    x		any, &any

    return	int

DESCRIPTION
    Determine if x is a file.  This function will return 1 if x is
    a file, 0 otherwise.

EXAMPLE
    > a = files(0)
    > print isfile(a), isfile(files(1)), isfile(1)
    1 1 0

LIMITS
    none

LIBRARY
    none

SEE ALSO
    isassoc, isident, isint, islist, ismat, isnull, isnum, isobj,
    isreal, isstr, issimple, istype