Perl in text formatting

1.

Selecting range of text from a log file, particularly timed data –

perl -ne ‘print if m{^2008-12-22 10:46} .. m{^2008-12-22 11:52}’ log.2008-12-22 >~/20081222-ws02

or

perl -ne ‘print if m#Full thread# … m#”VM Periodic Task#’ >~/out

2.
Perl is as terse as it is powerful. Here’s a simple substitute command that might come in very handy:

perl -p -i -e ‘s/this/that/g’ filename

This command replaces the string *this* with the string *that* in the specified file — much the same as the scripts recently included in this column.

Just remember that the arguments spell “pie” and that the substitute command looks like a substitute command in sed. Since the command replaces the original file with the changed one, it’s very quick. Arguments:

p print
i in-place edit
e execute the following command

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