tldr/pages/common/sed.md

sed

Edit text in a scriptable manner.

• Replace the first occurrence of a regular expression in each line of a file, and print the result:

sed 's/{{regex}}/{{replace}}/' {{filename}}

• Replace all occurrences of an extended regular expression in a file, and print the result:

sed -r 's/{{regex}}/{{replace}}/g' {{filename}}

• Replace all occurrences of a string in a file, overwriting the file (i.e. in-place):

sed -i 's/{{find}}/{{replace}}/g' {{filename}}

• Replace only on lines matching the line pattern:

sed '/{{line_pattern}}/s/{{find}}/{{replace}}/' {{filename}}

• Delete lines matching the line pattern:

sed '/{{line_pattern}}/d' {{filename}}

• Print only text between n-th line till the next empty line:

sed -n '{{n}},/^$/p' {{filename}}

• Apply multiple find-replace expressions to a file:

sed -e 's/{{find}}/{{replace}}/' -e 's/{{find}}/{{replace}}/' {{filename}}

• Replace separator / by any other character not used in the find or replace patterns, e.g., #:

sed 's#{{find}}#{{replace}}#' {{filename}}

• Print only the n-th line of a file:

sed '{{n}}q;d' {{filename}}