sed swallows braces / curly brackets

Question

I've got a LaTeX file containing

\newcommand{\revision}{value}

And during CI I want to do the following:

REV=${CI_COMMIT_TAG:-$CI_COMMIT_SHORT_SHA}
sed -i 's/{\\revision}{\(\w*\)}/\1'"$REV"'/' variables.tex

expecting something along the lines of \newcommand{\revision}{577f813d}

Unfortunately this happens:

> REV=test sed 's/{\\revision}{\(\w*\)}/\1'"$REV"'/' variables.tex
\newcommandvaluetest

Why does this happen?

Answer 1

Try this,

sed -e "s/\({\\\revision}\){\w*}/\1{$REV}/" variables.tex

\newcommand{\revision}{577f813d}

• sed required two black slashes to escape backslash.
• We should back-reference the {\\\revision} instead of {\w*}
• finally required a curl brace around REV as per our expected output