github.com/benhoyt/goawk@v1.8.1/testdata/gawk/regexpbrack2.awk (about)

     1  NR == 1 { gsub(/\\\\[;?!,()<>|+@%\]\[]/, " ") ; print "\"" $0 "\"" }
     2  NR == 2 { gsub(/\\\\[;?!,()<>|+@%\]\[^]/, " ") ; print "\"" $0 "\"" }