411 REFERENCE · Wikibooks
Perl Programming/Keywords/-w
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Perl -W -X Keywords
The -w keyword
-w is a file test that tests whether the file is writable by effective uid/gid or not.
It takes one argument, either a FILENAME, a FILEHANDLE, or a DIRHANDLE to test the associated file to see, if something is true about it. If the argument is omitted, it tests $_. -w returns 1 for true and an empty string for false. If the file doesn't exist or can't be examined, it returns undef and sets $! (errno).
Syntax
-w FILENAME
-w FILEHANDLE
-w EXPRESSION
-w DIRHANDLE
-w
Perl -W -X Keywords
</noinclude>