CGI Scripts

Sooner or later most non-trivial web sites will need one or more custom programs that run on the server (aka "CGI scripts"). In general we recommend that any new scripts be written using the PHP programming language because it's faster, more secure, and more portable than the alternatives. However, if you want to run a pre-made script that is written in some other language, or you simply prefer to program in another language (like perl, python, ruby, tcl, etc) we support that too.

Unlike PHP, which is built in to the web server software itself, scripts written in other programming languages are run as external programs. In order to maintain security an intermediate program called "SafeCGI" is used which sets up a secure environment before launching the script. All of this should be transparent to you, however.

There is no need to place your CGI scripts in a special directory, but you can if you want to. Just keep in mind that you can't use the name "cgi-bin" for this directory because it's used for cgi scripts shared by all users. The location of the script doesn't really matter as long as it's in your web space. What's important is the filename of the script and the file permissions.

Any file in your web space that ends with ".cgi" will be treated as a CGI script and SafeCGI will attempt to run it. It must be owned by you and have execute privileges enabled. The file itself may be a binary executable (as long as it's compatible with our servers), or (more commonly) a text file containing a script written in an interpreted language like perl or python. For interpreted languages, the first line of the file is generally a "bang path", which tells the operating system which program should be invoked to interpret the rest of the code in the file.

Common bang paths include:

#!/usr/bin/perl
#!/usr/local/bin/python
#!/usr/local/bin/ruby

Note that certain filename extensions will force a specific interpreter. For example, if your script name ends with ".pl", perl will be used regardless of the bang path. An extension of ".py" will use python, and ".rb" will use ruby.