Re: Opening Dual WIndows in Batch FIle

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"billious" <billious_1954@xxxxxxxxxxx> wrote in message news:4aa8c316$0$27605$5a62ac22@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
dbareis wrote:
On Sep 10, 8:56 am, "Al Dunbar" <aland...@xxxxxxxxxxx> wrote:
[snip - START command documented syntax]

Dennis is right, though, in deducing from the help text that the
title is "optional". It is just that it is only optional when it is
not required.

/Al- Hide quoted text -

- Show quoted text -

Thanks for that, and it wasn't required (for my example commands) as
the
command doesn't start with a double quote.

Bye,
Dennis

I'd suggest it's very optimistic to rely on the documentation, given the originator's expression skills. Despite the availability of spelling-checkers and syntax-analysers, the documentation contains such blunders as "hexidecimal" and displays a confusion about the use of singlar and plural. Evidently, it was not deemed appropriate to use these tools - or perhaps it displays a worrying level of confidence in them.

The same person also appear to believe that such constructs as '+=' are so self-evident that they require no explanation, that there is no need to allow a universal-format response for date (like CCYYMMDDHHMMSS for instance) and that whereas 0x is implemented to explicitly specify hex in SET, there is no need to allow 0d for decimal and 0o for octal. It appears that this person's view of the world is that Octal is so much more important than decimal that a leading zero is interpreted as octal, and the consequent pitfalls can be disclaimed by a note in the documentation. No need to document that a leading semicolon will cause FOR /F to disregard a line, of course. That's just so obvious and unimportant it doesn't require as much as a note.

I've tried to analyse the syntax for the START command, and I'll admit that I've only tried unquoted and quoted strings - no unbalanced-quotes, embedded quotes or alternative separators like semicolons or tabs. What I conclude is this:

1. If there is a single argument, that argument will be executed, whether or not it is quoted.
2. If the first argument is NOT quoted, then that first argument will be executed with parameters of the remaining arguments
3. If the first argument IS quoted, then that will be used as the TITLE.
3a If the second argument is NOT quoted, then the second argument will be executed with parameters of the remaining arguments
3b If the second argument IS quoted then an attempt will be made to execute that part of the command-line AFTER the opening quote of the second argument UP TO the final quote on the line, with parameter(s) of the remainder of the line after the separator following the opening quote of the second argument MINUS the final quote on the line.

This should all be clear, I hope - with the exception of 3b, which I'll exemplify:

START "s tring1" "s tring2" "s tring3" "s tring4" parm5

Where there is a deliberate space between "s" and "tring"

will select (parameters delimited by [] for clarity)
[s tring1] as TITLE
[s] as executable
[tring2"] as executable's first parameter
["s tring3"] as executable's second parameter
["s tring4] as executable's third parameter
[parm5] as executable's fourth parameter

Note that the actual executable is that part before the space-separator; the first parameter delivered has an unbalanced quote and the third parameter is missing the closing quote.

Observe the response should the target executable ([s] in this case) not exist - the executable reported as not existing is that command-line portion up to the final quote, not simply to the first separator following the opening quote on the second argument...!

Nice work, providing the above blow-by-blow description of how start parses its parameters. No matter how succinctly this can be summarized, it is a good illustration that always including a title parameter simplifies the calculations one might have to go through to determine if it is required. And we haven't even considered the possibility of using a non-literal string as the executable to be started, i.e.:

set exe="C:\a b\c.exe"
start %exe% 1.txt


There's probably a better way to express this observation. What is certain is that the description of the title as being optional is hard to justify.

Well, it *is* optional in that it is not always required. Where the docs fail is in not explaining the why's and the wherefore's of this, leaving it up to this newsgroup to explain.

Also, I suspect that the help file info was written after the command was developed, and by people other than the development team. We can argue that the help text is inaccurate, or we could lay more of the blame on the command itself. Unfortunately, neither case will cause either of the blameworthy parts to be fixed.

/Al


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