[SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z]

U \ modifier
ucwords() function
Unix
    grep command 2nd 3rd
Unix epoch
Unix who command, reading
unlink() function
unserialize() function 2nd
unset() function
update() function
    object hierarchies
updating
    SQLite tables
    tables
uploading
    files
        forms
    scripts
urlencode() function
user input
    adding to databases 2nd
    escaping 2nd
    HTML forms
        accessing with SELECT elements 2nd 3rd
        importing into global variables 2nd
        reading 2nd 3rd
        receiving
    importing into global variables
user-agent client header
user-defined functions
    values, returning 2nd
users
    redirecting (forms) 2nd 3rd
users array
    elements
usr/local/lib directory
    php.ini file location