Gateway Programs and Forms

• Can be interfaced to some HTTP servers (such as NCSA httpd).
• Can obtain external, dynamic information.
• Outputs a document, as text, HTML, or other MIME formats
  (e.g. the date gateway).
• Can accept input from the client (via the server):
  • simple GET queries, such as ISINDEX searches, via command arguments
    (e.g. the finger gateway),
  • complex POST queries, such as the content of a fill-out FORM, via the standard input
    (e.g. the mailer gateway).
• Can be any type of program allowed on the server host
  (on UNIX: compiled binary, shell script, perl script, or a combination).