How to search for strings on uncommented Python lines using a Bash function
Recently I found myself wanting an easy way to grep for strings in uncommented lines in my Python files. I was tired of re-typing the same --excludes and regexes over and over. I'd already been using alias for a while to shorten commands I found myself using a lot, but I needed a way to plug a string into the regex at runtime, and I found myself hindered by the fact that I couldn't reference arguments to the alias in its definition. I remembered that Bash lets you define new functions right on the command line, so I ended up writing a Bash function:
function pygrep () { grep -r --exclude="*.pyc" --exclude="*.swp" ^[^#]*1ドル.* ${@:2}; }Usage:
pygrep "search_string_here" optional_list_of_files_and_directoriesIn the function definition above, 1ドル stands for the first argument to the function. 2ドル would, of course, stand for the second, 3ドル would stand for the third, and so on. $@ is an array of all of the arguments to the function. In this example, I'm grabbing all its elements from the second element on. If I wanted to just get the two arguments following the first one, I could have instead referenced ${@:2:2}. The number after the first colon is the starting index (inclusive), and the number after the second colon is the number of elements to grab.
If you find a function particularly useful (as I've found the one above), don't forget to add it to your ~/.bashrc file so you can continue using it in your next Bash session.