Bin Chen Bin Chen - 3 months ago 8
Linux Question

Add a prefix string to beginning of each line

I have a file below :

line1
line2
line3


And I want to get

prefixline1
prefixline2
prefixline3


I could write a ruby script but it is better if I do not need to.

EDIT:
prefix
will contains
/
, it is a path ,
/opt/workdir/
for example.

Answer
sed -e 's/^/prefix/' file

# If you want to edit the file in-place
sed -i -e 's/^/prefix/' file

# If you want to create a new file
sed -e 's/^/prefix/' file > file.new

If prefix contains /, you can use any other character not in prefix, or escape the /, so the sed command becomes

's#^#/opt/workdir#'
# or
's/^/\/opt\/workdir/'