Question

This is what I want to do:

If I encounter a pattern like

someVarX: val1

I want to insert

someVarY: val2

on the next line

…BUT HERE IS THE CATCH:

someVarX: val1 can have a number preceding blank spaces (indentation) counting anywhere between 0 and N and I also want to repeat that exact indentatation on the next line. So if someVarX: val1 has 3 preceding blank spaces, then I also want someVarY: val2 to have 3 preceding blank spaces.

This is what I tried:

s/\n( +)someVarX: val1/\n${1}someVarX: val1\n${1}someVarY: val2/

hoping that ${1} would insert the capture group from the search pattern into the replace string but got:

sed: command garbled: ...

The OS os SunOS 5.10. I couldn’t run sed --version, it told me the option –version was illegal.

Any idea?

Answer 1

This is what finally worked:

        s/^\( *\)someVarX: val1/&\
\1someVarY: val2/

It had to be done on two lines of a sed S&R spec file, let’s call it snrspec.sed, which also contained other S&R instructions:

1,/^END/{
        s/ABC/XYZ/

        ...

        s/^\( *\)someVarX: val1/&\
\1someVarY: val2/

}

and then I called sed:

sed -f snrspec.sed inputfile.txt > outputfile.txt

However, I would prefer to do it in a single line, if anyone knows how to, as it would obviously be more elegant. But the above worked and I performed my massive S&R operation.