Grep is a wonderful UNIX command line tool that searches for text in plain-text files. It can search one file or many, and its search phrase may be a regular expression. Grep is an essential tool for anyone who uses UNIX-based systems.
Grep is also useful when programming. Let’s face it: Sometimes, it’s easier to grep when searching for text rather than using fancy search tools or IDE features. I find this to be especially true for languages with a dynamic or duck type system like Python because IDEs cannot always correctly resolve links. Grep is fast, easy, and thorough. I use grep a lot when developing Django web projects because Django development relies heavily upon the command line.
The main challenge with grep is filtering the right files and text. In a large project, false positives will bloat grep’s output, making it harder to identify the desired lines. Specifically in a Django project, files for migrations, language translations, and static content may need to be excluded from searches.
I created a few helpful aliases for grepping Django projects:
alias grep_dj='grep -r --exclude="*.pyc" --exclude="*.mo" --exclude="*.bak"' alias grep_djx='grep_dj --exclude="*.po" --exclude="*/migrations/*"'
The alias “grep_dj” does a recursive directory search, excluding compiled files (.pyc for Python and .mo for language) and backup files (.bak, which I often use for development database backups). The alias “grep_djx” further excludes language messages files (.po) and migrations.
To use these aliases, simply run the alias commands above at the command line. They may also be added to profile files so that they are created for every shell session. Then, invoke them like this:
> cd /path/to/django/project > grep_djx "search phrase" *
Other grep options may be added, such as case-ignore:
> grep_djx -i "another phrase" *
These aliases are meant purely for the convenience of project-wide text searching. If you need to pinpoint specific files, then it may be better to use the raw grep command. You can also tweak these aliases to include or exclude other files – use mine simply as an example.