5.6.2 Searching

If you are working with the git repository, the most useful tool on the command line to search text is git grep, which recursively scans the repository’s files for strings using regular expressions (regex). This manual cannot give an introduction into the use of regular expressions; there are plenty of resources in the internet that may help you.

Files not managed by git in a repository (for example, all files generated during compilation or building the documentation) cannot be searched with git grep, though. In such cases you might use the standard grep tool instead, which has almost exactly the same syntax.

Another limitation of both grep and git grep is their inability to search a string across multiple lines,⁹ which would be extremely helpful in finding arguments of Texinfo commands. A solution is to use a variant of grep called pcregrep (or its newer version pcre2grep – the acronym PCRE stands for Perl Compatible Regular Expressions). You most likely have to install this program; look for packages called ‘pcre-tools’, ‘pcre2-tools’, or something similar.

As an example, let’s assume that you want to find all occurrences of @rweb{Easier editing} within Documentation/en/. After changing to this directory, a search with

git grep '@rweb{Easier\s*editing}'

might return the following.

usage/external.itely:editors are listed in @rweb{Easier editing}.
usage/external.itely:are listed in @rweb{Easier editing}.

[The string \s* means to search for whitespace (\s) zero or more times in succession (*).]

On the other hand, a search with

pcregrep -r -M '@rweb{Easier\s*editing}' .

shows one more hit.

./learning/installing.itely:For more information, see @rweb{Easier
editing}.
./usage/external.itely:editors are listed in @rweb{Easier editing}.
./usage/external.itely:are listed in @rweb{Easier editing}.

[Option -r enables recursive searching of the current directory (‘.’), option -M activates multi-line searching.]