From Fedora Project Wiki
Virtual Provides: in packages
Several packages in Fedora may provide similar functionalities. In some of these cases, it's beneficial to add a "virtual provision" into those packages so that other packages can have dependencies to the functionality they require instead of hardwiring a specific implementation. Note that file based dependencies can in some cases be used instead of these provisions, and can sometimes be "better" than these.
2007-04-08: it appears that these virtual provides and their purposes are not documented anywhere, so this page collects some information based on which they can hopefully be properly documented somewhere later. Feel free to add whatever is missing.
Current Provides:
| Provides: | Purpose |
| MTA | Full featured Mail Transfer Agent, should be sendmail compatible. This should not be useful: if a smtp server is needed, the server(smtp) virtual provides should be used instead, and if the package provides a command compatible with /usr/sbin/sendmail, /usr/sbin/sendmail should be used as a virtual provide and if a packages needs /usr/sbin/sendmail it should require it |
| ocaml(Module_name) = MD5sum | OCaml module, where MD5sum is the digest of the module's signature and implementation (see ocamlobjinfo command) |
| ocaml(runtime) = X.Y.Z | OCaml compiler ABI |
| perl(:MODULE_COMPAT_X.Y.Z) | Perl ABI version, versioned install dirs. |
| perl(module_name) | provides the perl module_name module |
| python(abi) = X.Y | Python ABI version, versioned install dirs. |
| tcl(abi) = X.Y | Tcl ABI version, versioned install dirs. |
| smtpdaemon | deprecated by server(smtp) |
| server(port_name) | provides a local server listening on port_name. port_name is the service name associated with that port number in /etc/services, or the port number when no record exists in /etc/services |
| tex(tex) | basic TeX system, with the tex command, basic kpathsea related executables and scripts, some fonts |
| tex(dvips) | dvips implementation |
| tex(latex) | LaTeX implementation |
| tex(context) | ConTeXt implementation |
| tex(east-asian) | support for east-asian languages for TeX and LaTeX, including at least ptex and platex |
| text-www-browser | special provide for TEXT web clients e.g. docbook-utils, elinks, w3m, xmlto (Added as part of bug https://bugzilla.redhat.com/174566) |
| webserver | A web server. TBD: does this imply something about doc root being /var/www/html? What about CGI capabilities? |
| webclient | Something that can access http urls, e.g. wget, curl, links, firefox |
| xemacs(bin) | An actual implementation of XEmacs (flavours: full blown X, minimialish -nox) |
Features that could benefit from being defined as Provides:
- Browsers that load and use Mozilla plugins from %{_libdir}/mozilla/plugins. File based dependency on the dir works, but causes the need for yum to download file metadata.
- console web browsers, e.g. links links2 elinks lynx w3m