Add examples to the ack cookbook

[petdance]

ack 3, currently in development, will include a cookbook of examples for folks to try. Here's an example:

Find "goats" in every file that also contains "cows"

ack -l cows | ack -x goats

What examples do you have that can get added to the cookbook? Post them here.

[petdance]

From @n1vux: document use of lookbehind and other useful Perl Extended RE idioms in a separate doc section (have some a few bits now but scattered)

[petdance]

The example I always use in presentations:

Find all the headers used in your C programs and dedupe them:

ack '#include\s+<(.+)>' --cc --output='$1' | sort -u

[petdance]

Pull out examples from the main ::Manual, especially the "TIPS" section.

[petdance]

Searching for a method call:

ack -- '->method'

or

ack '[-]>method'

[petdance]

Search for all the files that mention Sys::Hostname but don't match hostname. Add -I because I have --smart-case on in my .ackrc.

ack -l Sys::Hostname | ack -x -L -I hostname

Related: Find files that are using both use base and use parent.

ack 'use base' -l | ack 'use parent' -x

[n1vux]

via @clmagic
egrep -- "\t-\t-\t-\t-\t" entries.txt |sort -k3V # Get the entries with 4+ null fields and sort the entries by IPv4 (-V) in the 3rd column.
(technically it's 4+ adjacent null fields)

[petdance]

Mention dirty and/or git diff --name-only.

[hoelzro]

Open list of matching files in Vim, searching for your search term:

$ ack my_search_term
<results>
$ vim $(!! -l) +/!$

• !! expands to the previous command - ack my_search_term in the example
• $(...) expands to the output of the command in the parens, so the output of ack my_search_term -l in the xample
• +/<term> tells Vim to start searching for <term> once it opens
• !$ expands to the last argument of the previous command - my_search_term in the example

Small caveat: Vim patterns and Perl regexes have some overlap, but they are different, so this doesn't work so great when you have a more complex regex as your search term.

[petdance]

See all the .vim files in your ~/.vim directory, except in the bundle/ directory.

ack -f --vim ~/.vim --ignore-dir=bundle

[petdance]

ack -g tax --ruby Finds all the ruby files that match /tax/.

vim $(ack -l taxes) open all the files that have taxes in them.

ack -f --perltest | xargs prove Find all the Perl test files and feed them to xargs which runs them all against the prove command.

[petdance]

We could have entire section just about ack -f and ack -g.

[petdance]

Find places where two methods with the same name are being called on the same line.

ack -- '->(\w+).*->\1\b'

[petdance]

Find all the places where I'm making a call like sort { lc $a cmp lc $b }. It gets false positive, but it's pretty useful.

ack '\bsort\b.+(\w+).+\bcmp\b.+\b(\1)\b'

[petdance]

Show a range of lines in a file: ack --lines=830-850 filename. And use -H to show what line numbers are.

[petdance]

Find modules that are not using Test::Warn:

ack -L 'warnings?_' $(ack -l Test::Warn)