sed¶

Resources¶

linux - sed command with -i option (in-place editing) works fine on Ubuntu but not Mac

Inplace editing¶

Use -i.

Print a range of lines¶

sed -n '1,100 p' file.txt

Use environment variables in sed¶

# sed -e "s/$WIKI_DIR\/docs/string_to_replace_with/"  this doesn't work
sed -e 's@'"$WIKI_DIR/docs/"'@string_to_replace_with@'
sed -e "s|$WIKI_DIR/docs/|string_to_replace_with|"

Delete lines in a file¶

sed -i '' '1,3d' file.txt
# deletes lines 1-3 in place

Delete lines that match a pattern¶

sed -i '' '/somepattern/d' file.txt

Remove nth line of stdin¶

echo '1\n2\n3\n4'
1
2
3
4
echo '1\n2\n3\n4' | sed 2d
1
3
4

Add closing tag to html tags¶

find docs -name '*.md' | xargs sed -i "" '/<img/ s/>$/\/>/'

Add a character in the beginning of a line¶

Say I want to add # in the begining of the first line.

find docs -name '*.md' | xargs sed -i "" '1s/^/# /'