regex - Using $1 in regexp within a Makefile -
this question has answer here: escaping in makefile 2 answers i try replace following perl command: perl -c -p -i -e 's/([\?\.\!])\n/$1 /g' html/數14.html the result fine when call command line. when call within makefile doesn't work. apparently $1 interpreted shell variable. in makefile looks this: 數14.html: 數14.adoc 40_2064_im\ strand-appartment.adoc 41_2064_ein\ plan.adoc 42_1915_in\ einer\ suppenküche.adoc asciidoctor -d html parts/數14.adoc perl -c -p -i -e 's/([\?\.\!])\n/$1 /g' html/數14.html how can have normal regexp behaviour here? makefiles interpret $ sequences before executing commands, disregarding quoting. in order escape $ in makefile, write $$ - result in single $ in command.