Manipulate ampersand in sed

Question

Is it possible to manipulate the ampersand in sed? I want to add +1 to all numbers in a file. Something like this:

sed -i "s/[0-9]\{1,2\}/$(expr & + 1)/g" filename

EDIT: Today I created a loop using grep and sed that does the job needed. But the question remains open if anyone knows of a way of manipulating the ampersand, since this is not the first time I wanted to run commands on the replacement string, and couldn't.

Answer 1

You may use e modifier to achieve this:

$ cat test.txt
1
2
$ sed 's/^[0-9]\{1,2\}$/expr & + 1/e' test.txt
2
3

In this case you should construct command in replacement part which will be executed and result will be used for replacement.