Web/HTTP Services
8.1. Q - How does the HTTP Server work?
A - This version of the HTTP server is not meant to a complete implementation. It is only a
starting point.
GS3 Technologies will be implementing more complex versions in the future.
The HTTP server, as of version 2.0.0.1, responds as HTTP Version 1.0.
The only command implemented in this version is GET.
The server can have many sockets open simultaneously, with the maximum number set in
"sysconfig.h".
The server multitasks the reads from the internal web pages and responses to the web
clients.
In this implementation, the web pages are in the "index_html.c" file.
8.2. Q - How much memory does it use?
A - HTTP is expensive in terms of memory. Approximately 62 bytes are used for each open
connection and about 4K of program memory.
8.3. Q - What variables are defined for substitution in the HTTP response?
A- The following variables can be included in the HTML page and will be substituted by the
server to an appropriate string. In order for the variables to be substituted, they must be
prefixed with the two character "$$" sequence.
DATELONG - The string will expand to include the complete local date with
different device time data.
e.x.
SYS: 11/06/2005, 0:00:15.460
RTC: 11/06/2005, 0:00:15.860
NTP: 11/06/2005, 0:00:11.953
LOC: 11/05/2005, 19:00:15.460 - EST
DATE - The string will expand to include the local date in mm/dd/yy format.
TIME - The string will expand to include the local time in hh:mm:ss format.
IFCONFIG - The string will expand to include the response from the internal
uptime command.
e.x.
IP: 10.0.0.37, Netmask: 255.255.255.0
Gateway: 10.0.0.11, MAC: 00:04:A3:00:00:00
NTP server: 10.0.0.3, DHCP is Disabled
NETSTAT - The string will expand to include the response from the internal
netstat command.
e.x.
Packets Sent: 2403, Received: 2570
NIC I/O Errors: 0, NIC I/O Errors LL: 0
Protocol Errors: 0
