Keywords: clamdoc

## Requirements

The following elements are required to compile ClamAV:

- zlib and zlib-devel packages
- gcc compiler suite (tested with 2.9x, 3.x and 4.x series)
  If you are compiling with higher optimization levels than the default one (-O2 for gcc), be aware that there have been reports of misoptimizations. The build system of ClamAV only checks for bugs affecting the default settings, it is your responsibility to check that your compiler version doesn't have any bugs.

The following packages are optional but highly recommended:

- bzip2 and bzip2-devel library
- GNU MP 3
  It's very important to install the GMP package because it allows `freshclam` to verify the digital signatures of the virus databases and scripted updates. If freshclam was compiled without GMP support it will display "SECURITY WARNING: NO SUPPORT FOR DIGITAL SIGNATURES" on every update. You can download GNU MP at `http://www.swox.com/gmp/`
  A note for Solaris/SPARC users: you must set the ABI system variable to 32 (e.g. `setenv ABI 32`) before running the configuration script of GMP.