This package provides support for CGI programming when the HTML library of package
html is used. It contains the library
HTML.CGI which is an auxiliary library to implement dynamic web pages with the library
As a prerequisite to execute dynamic web pages, the installation of the Curry Port Name Server (CPNS) and the HTML/CGI registry provided by this package is required. This can be easily done by the commands
> cypm install cpns
> cypm install html-cgi
These commands install the executables
curry-cpnsd (CPNS demon) and
curry-cgi (HTML/CGI registry) in the bin directory of CPM. These executables are invoked during the execution of a dynamic web page.
Furthermore, one should also install the package
html by the command
> cypm install html
This installs the executable
curry-makecgi which is used to compile a dynamic web script implemented in Curry.
The CGI registry is a table of all active CGI server processes implementing dynamic web pages. Such a process is started when a dynamic web page is accessed on the web server. To transmit user inputs (provided via CGI) to the corresponding server process, the executable
curry-cgi provided by this package is used.
CGI server processes are automatically started and terminated (e.g., after 120 minutes of inactivity). In order to manage these processes manually, one can access the CGI registry via the executable
curry-cgi. The following commands can be used to access CGI server processes:
> curry-cgi show
Shows all currently active servers (name and pids)
> curry-cgi sketch
Sketches the status of all currently active servers (date of next cleanup and dates of all currently stored event handlers)
> curry-cgi clean
Starts a cleanup on each server (usually, this is implicitly started whenever a dynamic web page is requested), i.e., expired event handlers are deleted. Morever, servers which are inactive for a long time (the exact period is defined in HTML.cgiServerExpiration) are terminated. Thus, it is a good idea to execute this command periodically, e.g., via a cron job.
> curry-cgi stop
Stops all currently active servers (however, there are automatically restarted when a user requests the corresponding dynamic web page) by sending them a termination message.
> curry-cgi kill
Kills all currently active servers by killing their processes. This could be used instead of
stop if some servers do not react for some reason.
The use of stop/kill might be necessary in order to restart servers that have required too much resources without free them (which could be the case if the underlying run-time system does not deallocate memory).
html contains a web script (see the README there) which can be installed on the web server to execute these commands. This might be necessary (instead of using
curry-cgi) if the web server has its own directory
/tmp which is not accessible from processes outside the web server.
/tmp/Curry_CGIREGISTRY : the data stored in the current registry