[Bash] grep command

The grep command searches for patterns within files and prints matching lines.

grep [options] [content] [file]

Search for a pattern in a file:

grep "pattern" filename.txt

Ignore case sensitivity:

grep -i "pattern" filename.txt

Search recursively in directories:

grep -r "partten" /path/to/directory

Show line numbers of matches:

grep -n "pattern" filename.txt

Example

vi exampletxt

Hello World
This is a sample file
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Another line with the word World

Search file:

 grep "World" example.txt

Hello World
Another line with the word World
grep -i "world" example.txt

Hello World
Another line with the word World

grep -n "line" example.txt

5:Another line with the word World

Search directory:

mkdir test_directory
echo "This is a sample text file" > test_directory/file1.txt
echo "Another sample text file" > test_directory/file2.txt
grep -ri "sample" test_directory # case insensitive

test_directory/file2.txt:Another sample text file
test_directory/file1.txt:This is a sample text file