Re: Regular Expression Help

Your missing the anchors, and the /g, the /i and the parens are unnecessary:

/^\w+\.\w{3}$/
[download]

But that's not perfect because \w allows for digits, so:

/^[a-zA-Z_]+\.[a-zA-Z_]{3}$/
[download]

To allow filenames with no extention or with extentions short than 3 characters:

/^[a-zA-Z_]+(?:\.[a-zA-Z_]{0,3})?$/
[download]

Comment on Re: Regular Expression Help Select or Download Code

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Re^2: Regular Expression Help by Anonymous Monk on Jan 06, 2006 at 16:32 UTC
One of my problems is not to allow file names without extentions and with no less than 3 characters.	[reply]
Re^3: Regular Expression Help by ikegami (Patriarch) on Jan 06, 2006 at 16:46 UTC
No problem. Just use the second snippet instead of the third one.	[reply]
Re^3: Regular Expression Help by Anonymous Monk on Jan 06, 2006 at 16:48 UTC
How do I say match anything but not allow spaces between words? Like: `if($filename=~/.!\s[.](?!bat$\|exe$).$/gi){...` [download] This is not working if I use .*!\s	[reply] [d/l]
Re^4: Regular Expression Help by thedoe (Monk) on Jan 06, 2006 at 19:11 UTC
ikegami's second regular expression will still do what you want. This only allows the characters a-z (upper and lower case) for the file name and an extension of 3 of the same characters. No spaces allowed, no weird characters. My recommendation is to use this one. Also, for general questions on regex, take a look at perlre. This will answer many of your questions and broaden your overall understanding of regular expressions.	[reply]