i am trying to install apc on redhat so i did: pecl install apc i said yes to: Use apxs to set compile flags (if using APC with Apache)? [yes]: and i get this: checking for re2c... no configure: WARNING: You will need re2c 0.9.11 or later if you want to \ regenerate PHP parsers. and checking whether apc needs to get compiler flags from apxs... Sorry, I was not able to successfully run APXS. Possible reasons: 1. Perl is not installed; 2. Apache was not compiled with DSO support (--enable-module=so); 3. 'apxs' is not in your path. Try to use --with-apxs=/path/to/apxs The output of apxs follows /tmp/tmpJQuZdD/APC-3.0.16/configure: line 3846: apxs: command not found configure: error: Aborting ERROR: `/tmp/tmpJQuZdD/APC-3.0.16/configure --with-apxs' failed what could be the problem? Thanks