Add some interface to search gziped files

[Fuco1]

ag provides very useful switch -z that allows you to search in archives. For example, on many unix platforms emacs sources (and many other software) come gziped. Right now I can't use ag from emacs to search these.

I'm not sure how to handle this, maybe C-u could ask for additional flags? A global setting seems dangerous since user might have huge zip archives around.

[Wilfred]

It would certainly be a useful feature, but I'm not sure how to handle it either. As a quick workaround, you could simply do (add-to-list 'ag-arguments "-z"), but this will affect all ag.el usage.

The number of ways ag.el can be used for searching is gradually growing, so the combinations possible is growing very quickly. We have:

• Search term as plain text or PCRE pattern
• Prompt for directory, or guess from the current directory and VCS
• Search all files, or limit to files whose name matches a certain pattern

There are 8 possible combinations here, and we don't actually support all of them (for example, there's no ag-project-files-regexp). If we add another option we're up to 16 combinations.

So yes, our current UI isn't perfect. I think C-u allowing you to temporarily modify the arguments passed to ag would help in your case. I can't see any better solution, but I'm open to suggestions.

[Fuco1]

Ideally it would be reflected in some variable, so I could make it directory local (e.g. in the emacs sources directory), but not elsewhere. I didn't know about ag-arguments, that should do nicely when I set it in the directory.

C-u optionally reading a value for that variable would be good interface I think, dired and dired-find work similarly.

[Wilfred]

Sorry for the delay on this. I've fixed it. I've gone for using C-u to specify a value, since it's used in dired too. Let me know if you like it and/or if there's any way it could be improved.