$ferr
From Scriptwiki
Indicates there was a file error of some kind.
$ferr
Returns 1 if an error occured, 0 else.
Example
; we open a file we probably don't have, but silently (the dot infront of the command) .fopen moo we_dont_have_this_file.txt ; check whether $ferr returns 1 (true) and echo it if ($ferr) { echo -a An error occured. } ; else echo that no error occured. else { echo -a No error occured. }