Re: A rare, insidious logfile parsing pitfall

You might have a problem if another bracket shows up later on in the line for some reason. Try this:

/^(\S+) (\S+) ([^\[]+) \[...

Of course if you're using Apache just use the CustomLog directive to define your own easily parsed log file format and be done with it.

Comment on Re: A rare, insidious logfile parsing pitfall Download Code

Replies are listed 'Best First'.
Re: Re: A rare, insidious logfile parsing pitfall by blakem (Monsignor) on Oct 28, 2001 at 14:26 UTC
Inside a character class, you don't need to escape '['. Your class above can legally be written as `[^[]`. You do need to escape ']' inside a character class, however, otherwise it will be interpreted as the closing bracket of your class. So, `[^a]]` means "any character other than 'a' followed by a ']'." Its the exact opposite elsewere in the regex where an unescaped ']' is literal but '[' is not. To avoid mistakes, I usually escape both of them to get their literal interpretation no matter what their context. Just a clarification, not necessarily a correction. -Blake	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re: Re: A rare, insidious logfile parsing pitfall
by blakem (Monsignor) on Oct 28, 2001 at 14:26 UTC

[^[]

[^a]]

Its the exact opposite elsewere in the regex where an unescaped ']' is literal but '[' is not. To avoid mistakes, I usually escape both of them to get their literal interpretation no matter what their context.

Just a clarification, not necessarily a correction.

-Blake

[reply]
[d/l]
[select]