
This is the Title of the Book, eMatter Edition
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Using Swatch for Automated Log Monitoring
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the same file. We haven’t associated different expressions with different watched
files, nor can we. But what if you want to watch more than one logfile?
This is no problem. Although each .swatchrc file may describe only one watched file,
there’s nothing to stop you from running multiple instances of Swatch, each with its
own .swatchrc file. In other words, .swatchrc is the default but not the required name
for Swatch configurations.
To split our two examples into two files, put the lines in Example 12-28 into a file
called, for example, .swatchrc.hterror, and the lines in Example 12-29 into a file
called .swatchrc.htaccess.
Advanced Swatch Configuration
So far, we’ve considered only actions we want triggered every time a given pattern is
matched. There are several ways we can control Swatch’s behavior with greater gran-
ularity.
The first and most obvious is to exploit regular expressions. Regular expressions,
which really constitute a text-formatting language of their own, are incredibly power-
ful and responsible for a good deal of the magic of Perl, sed, vi, and many other Unix
utilities.
It behooves you to know at least a couple “regex” tricks. Trick number one is called
alternation, and it adds a “logical or” to your regular expression ...