8.5 How a Command Line is Processed
8.5 How a Command Line is
When FunnelWeb reads in a command line (from the console
or a script file), it processes it in the following sequence:
The command line is checked for non printable
characters. If there are any, they are flagged with a severe
All dollar string substitution variables in the command
line are replaced by their corresponding string. The
command line is processed from left to right.
Substitutions are performed non recursively.
At this point, if the line is empty, or consists entirely of
blanks, it is ignored and the interpreter moves to the next
A severe error is generated if the line at this stage begins
with a blank.
If the first character of the line is "
", the line is a
comment line and is ignored.
The run of non blanks commencing at the start of the line
is compared case insensitively to each of the legal
command verbs. If the command is illegal, a severe error
is generated, otherwise the command is processed.
Copyright Ross N. Williams 1992,1999. All rights
http://www.ross.net/funnelweb/reference/shell_processing.html [3/3/2000 10:46:13 PM]