iTP Secure WebServer System Administrators Guide (Version 7.5+)

Figure 5 CGI Relationships
Database
CGI Server Other
iTP Secure WebServer
Web Client
CGI Standard Input
& Environment Variables
Standard Output
CGI Support in the iTP Secure WebServer Environment
The iTP Secure WebServer offers two CGI execution environments; and both have advantages
over conventional CGI execution. These environments are:
• “Generic-CGI Server Class” (page 139)
• “Pathway CGI Server Classes” (page 140)
In addition, the “Servlet Server Class (SSC)” (page 141) provides a way of executing Java servlets.
Generic-CGI Server Class
The generic-CGI server class is a NonStop TS/MP server class that launches and manages
user-written Open System Services (OSS) CGI programs that conform to the NCSA CGI 1.1
specification. A CGI program written for another environment requires no change to communicate
with the generic-CGI server class.
As shown in “Generic-CGI Server class” (page 140) the generic-CGI server class translates the
NonStop TS/MP Pathsend protocol into a standard CGI interface. Your CGI program uses its
familiar stdin and stdout file descriptors and environment variables. The generic-CGI server
class makes it unnecessary for the httpd process to implement polling.
NOTE: CGI requests and replies can be of any length. For long requests and replies, the httpd
process and the process labeled "Pathway CGI main" exchange multiple Serverclass_send and
reply messages.
CGI Support in the iTP Secure WebServer Environment 139