Question

I can chain multiple sed substitutions and a awk operation to achieve this, but is there a single sed substitution that can do it?

Also is there any other tool that is more suitable for this parsing task?

Answer 1

You could try:

sed -r 's!rec:id=(.*?)&name=(.*?)&age=(.*?)!\1 \2 \3!' input_file

If you don’t know the rec:id etc in advance but you know there’s three, you could try:

sed -r 's![^=]+=(.*?)&[^=]+=(.*?)&[^=]+=(.*?)!\1 \2 \3!' input_file

If you don’t know how many &name=value pairs you’re after in advance but want to output all the values, you could try something like:

grep -P -o '(?<==)([^&]*)(?=&|$)' | xargs

where the -P means ‘perl regex’, the regex says “find the string followed by an & (or end of string) and preceded by and equals sign”, the -o means to print just the matches (ie the 1, zz, and 21) each on their own line, and the | xargs moves these from their own line to one line and space separated (ie 1\nzz\n21 to 1 zz 21).