2.2 Command Line Arguments

2.2 Command Line Arguments

Following the verb is the body of the command line which FunnelWeb parses

into zero or more 

arguments

 separated by runs of one or more blanks.

Tutorial

FunnelWeb_command_line =

Developer

   FunnelWeb_verb { {" "}+ argument }

Because some operating systems convert their command line to upper case

Reference

before handing it to the invoked program, FunnelWeb has been constructed so

1 Introduction

as to be 

insensitive

  to the case of its command line arguments. However, when

2 Interface

dealing internally with arguments, FunnelWeb 

preserves

  the case of its

3 Scanner

command line arguments so that it will be able to operate with operating

4 Parser

systems (such as Unix) whose file names are case dependent.

5 Analyser

A valid FunnelWeb argument consists of a 

sign

, an identifying 

letter

, and an

6 Tangle

optional 

string

 with no spaces separating them.

7 Weave

8 Shell

argument  = sign id_letter [non_blank_string]

9 Commands

sign      = "+" | " " | "="

10 Glossary

id_letter = "B" | "C" | "D" | "F" | "H" | "I" |

11 References

            "J" | "K" | "L" | "O" | "Q" | "S" |

            "T" | "W" | "X"

SEARCH

In addition there is a special form of argument that does not begin with a sign.

argument = non_blank_string_not_starting_with_+_=_or_ 

This form is exactly equivalent to the same string with "

+F

" prepended to it.

The semantic effect of these arguments is defined in terms of 

options

 which are

the internal parameters of FunnelWeb and which correspond closely with the set

of legal command line arguments. FunnelWeb has a predefined set of options

each identified by an identifying letter having two attributes: a 

string

 , and a

boolean

 . The boolean determines whether an option is turned 

on

  or 

off

 . The

string contains additional information depending on the option.

When FunnelWeb starts up, its options have predefined default values.

FunnelWeb then parses its command line sequentially from left to right

executing the effect of each argument on the argument s corresponding option.

The sign and the string components of the argument are processed

independently

 . A sign of + turns the option on. A sign of   turns the option off.

A sign of = leaves the option s boolean attribute unchanged. The argument string

replaces the string of the corresponding option, unless the argument string is

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