bash grep command-line text-processing
grep Basics
`grep` searches for patterns in files. It's one of the most useful commands you'll ever learn.
The name stands for "Global Regular Expression Print"—but you don't need regex to use it. Start simple.
bash
# Search for "error" in a file
grep "error" logfile.txt
# Case-insensitive search
grep -i "error" logfile.txt
# Show line numbers
grep -n "error" logfile.txt
# Search recursively in directories
grep -r "TODO" ./src
# Invert match (lines that DON'T contain)
grep -v "debug" logfile.txt