Re[2]: make error /usr/bin/ld: cannot find -lz

[root@gate root]# rpm -qa | grep zlib zlib1-1.2.1.1-3mdk zlib installed, any ideas? r> Install zlib library for your system.

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make faild with this error...

gcc -shared sql_mysql.lo -L/usr/lib -L/usr/lib/mysql r> /usr/lib/libmysqlclient.so -lz -lm -lssl -lcrypto -Wl,-soname -Wl,rlm_sql_my sql-1.0.1.so -?>>o .libs/rlm_sql_mysql-1.0.1.so /usr/bin/ld: cannot find -lz collect2: ld returned 1 exit status gmake[10]: *** [rlm_sql_mysql.la] Error 1

What is -lz ?