It may be limited, but seems to be a good start: $ cat <<HN | sed -e '/@/ s/\([a-z]\)\([A-Z]\)/\1-\l\2/g' > The following sed will replace camelCase only

It may be limited, but seems to be a good start: $ cat <<HN | sed -e '/@/ s/\([a-z]\)\([A-Z]\)/\1-\l\2/g' > The following sed will replace camelCase only if it can find an arobase > character in the current line, thus fooBar and bazThing won't be replaced > but @fooBar and @awesomeFooBarBazzProperty will. > True story. > HN The following sed will replace camelCase only if it can find an arobase character in the current line, thus fooBar and bazThing won't be replaced but @foo-bar and @awesome-foo-bar-bazz-property will. True story.