How to add a prefix string at the beginning of each line in Bash shell script on Linux?
How to add a prefix string at the beginning of each line in Bash shell script on Linux?
For example, assume we have a file a.txt:
line 1
line 2
I want to have,
pre line 1
pre line 2
You may use sed, the stream editor for filtering and transforming text:
sed -e 's/^/pre /'
For example,
$ echo "line 1
line 2" | sed -e 's/^/pre /'
pre line 1
pre line 2
You may also do prefix adding to lines of certain patterns. But this is out of this question.
You could use sed -i to save space and backup the file first.