Hi, I am now trying to install a C library zlib to be /usr/local/include/zlib, /usr/local/lib/zlib and /usr/local/share/man. Here is the relevent part in the configure file of the library:

prefix=${prefix-/usr/local}
exec_prefix=${exec_prefix-'${prefix}'}
libdir=${libdir-'${exec_prefix}/lib'}
includedir=${includedir-'${prefix}/include'}
mandir=${mandir-'${prefix}/share/man'}

First, what does "-" mean in "prefix=${prefix-/usr/local}"?
Second, how can I achieve what I want by calling "./configure --pathname=xxx"? If impossible, how to modify the configure shell script?

Thanks in advance!

./configure --prefix=/usr/local

;)