sed cheatsheet

sed '/begin api/q'

sed '/^# begin/,$d'

sed -n '/end api/,$p'

Print after a given line is found.

sed -n '/regex/!p'

Print everything except lines matching regex. Useful for printing files with comments.

Printing REGEX ranges

sed -n -e '/^START$/,/^END$/p'

suppress output and print REGEX range include (^START$,^END$) lines.

OR without “-n” (same result)

sed -e '/^START$/,/^END$/p;d'

print REGEX range and delete other output, the [;] character means run another expression on the input file which is ‘d’ stands for delete .

sed -e "1a ## HEADING 02:" README.md

this appends “## HEADING 02:” after the first line in the file README.md and print the result to stdout replace -e with -i to write the file .

sed -e "1i # HEADING 01:" README.md

the same as appending but before the first line.

With line number

sed -e "1,5d" README.md

delete a RANGE (i.e. including lines 1 to 5)

sed -e '1,5!d' README.md

delete everything (i.e. excluding lines 1 to 5) it is better to quote sed expressions with single quotes especially when there is a [!] character.

With REGEX matching

sed -e "/REGEX/Id" README.md

delete lines with /REGEX/ matched /I is for insensitive search

sed -e '/REGEX/Ip;d' README.md

this invert the previous sed command delete everything (excluding lines with REGEX)