r mode, writing data files, 70, 285
r+ mode, writing data files, 70
radio buttons, 28
rand() function, 293
reading
cookies, 153–154
data files, 72–73
rectangles
imagefilledrectangle() function, 221
imagerectangle() function, 221
relational databases, 78–80
REMOTE_ADDR environment variable, 61
rename() function, 287–288
request-response sequence, 30
require directive, 139
reset() function, 273
resources, support, 308–310
restart command, 6
return statement, 48–49
RGB values, images, 220
rmdir() function, 288
round() function, 294
ROWS attribute, 29