depends zlib

optional_depends "libpng"                               \
                 "--with-png=/usr"                      \
                 "--without-png"                        \
                 "for png image support"

optional_depends "pcre"                                 \
                 "--with-pcrelib=/ --with-pcreinc=/usr" \
                 "--without-pcre"                       \
                 "for pcre regex support"

optional_depends "onig"                                 \
                 "--with-onig=/usr"                     \
                 "--without-onig"                       \
                 "for onig regex support"
