sed命令中的正则表达式组

Question

For the following lines

DEV1 ABCDEFGHI
DEV2 ABCDEFGHI
QA1 ABCDEFGHI
QA2 ABCDEFGHI

how do I substitute it to be the following:

<!-- DEV1 ABCDEFGHI -->
<!-- DEV2 ABCDEFGHI -->
<!-- QA1 ABCDEFGHI -->
<!-- QA2 ABCDEFGHI -->

This is what I have so far but it isn't working for all rows:

echo $line | sed -E 's/(QA.)|(DEV.)(.*)/<!-- \1\2\3 -->/'

Answer 1

This is what you want:

echo "$line" | sed -E 's/(QA.|DEV.)(.*)/<!-- \1\2 -->/' 

The first group could be prefixed by QA or DEV , use the | or operator.

A few alternatives :

$ echo "QA2 ABCDEFGHI"|sed -E 's/(.*)/<!-- \1 -->/'
<!-- QA2 ABCDEFGHI -->

$ echo "QA2 ABCDEFGHI"|awk '{print "<!-- "$0"-->"}'
<!-- QA2 ABCDEFGHI-->