Sed Command Cheat Sheet
Basic Usage
sed 's/old/new/' filename
Replace the first occurrence of "old" with "new" in each line.
sed 's/old/new/g' filename
Replace all occurrences of "old" with "new" in each line.
sed -i 's/old/new/g' filename
Modify the file in place, replacing all occurrences of "old" with "new".
Common Options
sed -n '3p' filename - Print only the third line of the file.
sed -n '2,4p' filename - Print lines 2 through 4.
sed '3d' filename - Delete the third line.
sed '2,4d' filename - Delete lines 2 through 4.
sed '$d' filename - Delete the last line.
Advanced Usage
sed 's/old/new/2' filename - Replace only the second occurrence of "old" in each line.
sed '1,3s/old/new/g' filename - Replace "old" with "new" only in lines 1 through 3.
sed '/pattern/d' filename - Delete lines that contain "pattern".
sed 's/\bword\b/replacement/g' filename - Replace whole word matches only.
sed 's/\(old\)/\U\1/g' filename - Convert "old" to uppercase.
sed 's/\(old\)/\L\1/g' filename - Convert "old" to lowercase.