[Cuis-dev] [IMPROV] Configurable command line exception handling

[Juan Vuletich]

Hi Gerald,

Please check the attach. Besides being simpler and hopefully easier to 
understand, it allows each script to have its own set of arguments.

Perhaps we could add another getter to SystemDictionary, something like 
#lastCommandLineArguments or such, to fetch what's after '--'.

Thanks,

On 1/13/2023 1:18 PM, Gerald Klix via Cuis-dev wrote:
> I never received this message, therefore I am reseinding it:
>
>
> Hi Juan,
>
> let me answer questions one at time (even those that were not asked:)
>
> -q) If want to write small Cuis scripts, like the prototypical “Hello 
> World” program, you would write  something like this:
>
> squeak  -vm-display-null -headless Cuis6.0-5626 -d "StdIOWriteStream 
> stdout nextPutAll: 'Hello World!'; newLine. Smalltalk quit"
>
> If you want to dump all unknown contributors to a file; it would look 
> like this:
>
> squeak  -vm-display-null -headless Cuis6.0-5626 -d  "Smalltalk 
> unknownContributors printOn: StdIOWriteStream stdout. Smalltalk quit" 
> > unknownContributors.txt
>
> Of course all these one-liners will end with `Smalltalk quit`, 
> therefore I came up with a shorter way to achieve the same effect:
>
> squeak  -vm-display-null -headless Cuis6.0-5626 -d  "Smalltalk 
> unknownContributors printOn: StdIOWriteStream stdout" -q > 
> unknownContributors.txt
>
> -c) is completely useless, because the old implementation only accepts 
> one `-s` option.
> `-s` consumes and copies all the remaining arguments to 
> `startUpScriptArguments`,
> terminating the loop,I did not catch that detail.
> I will fix this in the next version of the change.
>
> --) Posix requires a program to stop option parsing once it encounters 
> a double dash.
> To give an example that proves the necessity of this behavior, just 
> try this in your Mac's terminal:
>
> echo Hehehe > -f
>
> Than try to delete the file named “-f” using `rm -f`. This does not 
> work, you have to use `rm -- -f`.
> You can also check git, grep, ls or any other little Unix utility . 
> Just check:
>
> echo Hehehe > -r
> ls -r
>
> vs.
>
> ls -- -r
>
> (I leave it as an exercise to the gentle reader to get rid of that 
> '-r' file.)
>
> Therefore handling `--` should be done correctly, because it avoids 
> unnecessary surprises.
> But it also makes it easy to pass arguments to code package (classes) 
> that are
> installed with "-r". This part of Haver's installation package could 
> be written in a less hacky way:
>
> https://hg.sr.ht/~cy-de-fect/HaverOnCuis/browse/haver/Haverize.pck.st?rev=tip#L131 
>
>
> The same is true for the `-d` option, you can implement `echo` with 
> Cuis like this:
>
> squeak -vm-display-null -headless Cuis6.0-5626 -d  "Smalltalk 
> startUpScriptArguments do: [ :arg | StdIOWriteStream stdout 
> nextPutAll: arg; space]. StdIOWriteStream stdout newLine" -q -- -n 1 2 
> 3 a b dee
>
> compare to
>
> echo -- -n 1 2 3 a b dee
>
> Of course you want '--' handled correctly in your Cuis scripts, there 
> is no use
> in every author implementing it again, when she needs it.
>
>
> #copyStartupScriptArgumentsFrom:)
>
> Simply creates a fresh copy of the arguments after `--` for
> each script, code file, package or piece of code passed on the command 
> line.
>
> There is a reason for recreating the array for each script, code file 
> etc.:
> I never like the Unix's getopt(3) behavior.
> «By default, getopt() permutes the contents of argv as it scans,
> so that eventually all the nonoptions are at the end.»
> (https://www.man7.org/linux/man-pages/man3/getopt.3.html)
> Option parsing and program should no mess with the command line 
> arguments,
> this creates all sorts of nasty side effects.
>
> I hope I made my point about "end of options" and "--" clear.
> Please give some time to come up with a simpler version of the change.
>
>
> HTH,
>
> Gerald
>
>
> On 1/12/23 3:59 PM, Juan Vuletich wrote:
>> Hi Gerald,
>>
>> I agree that "do not ignore exceptions" doesn't need an argument. 
>> Then, maybe -e should never take an argument. I also like  -h and -v. 
>> Not sure about the value of -q, but I wouldn't mind including it.
>>
>> But can you explain -- and #copyStartupScriptArgumentsFrom: ? Can you 
>> give an example of use? I don't get it.
>>
>> Thanks,
>>
>> On 1/11/2023 6:53 PM, Gerald Klix via Cuis-dev wrote:
>>> Hi guys,
>>>
>>> thanks a lot for the encouraging feedback.
>>>
>>> It motivated me to to improve the exception
>>> ignoring stuff a bit; I just wanted '-e' to work without an argument.
>>> Then I noticed, that we can't handle options without arguments.
>>> Therefore I added, em well, some other options to the command line
>>> parsing code. I hope I haven't overdone it.
>>>
>>> You can now say `squeak Cuis.image -h` and get this output:
>>>
>>> --- snip --
>>> Command line options:
>>> -h Display this help message and quit
>>> -v Display the system information, containg the version and quit
>>> -q Just quit
>>> -e <exception> Evaluate exception and ignore it
>>> -e Set the exception to ignore to nil, i.e. do not ignore exceptions
>>> -r <feature> Require <feature>
>>> -d <code> Evaluate <code>
>>> -l <codeFile> Load e.g. file in <codeFile>
>>> -s <scriptFile> Evaluate code ein <scriptFile>
>>> -c Clear the array of start up script arguments
>>> -- end of options; stop processing options
>>>
>>> Arguments for scripts, code files, packages (and <code>):
>>> -s and -- store the remaining arguments in 'Smalltalk 
>>> startUpScriptArguments'
>>> -c clears the aforementioned array
>>> Packages (-f), code files (-l) and code (-d) gets a fresh copy of 
>>> the array if -- is present
>>>
>>> Multiple options:
>>> Options -e, -r, -d, -l, -s and -c can be passed multiple times
>>> --- snap ---
>>>
>>> Please review the change set and give me feedback.
>>> There might be some incompatibilities.
>>>
>>>
>>> HTH and Best Regards,
>>>
>>> Gerald
>>>
>>>
>>>
>>> On 1/11/23 2:33 PM, Dr. Nicola Mingotti wrote:
>>>> nice !
>>>>
>>>> Nicola
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On 1/8/23 17:21, Gerald Klix via Cuis-dev wrote:
>>>>> Hi all, Hi Juan,
>>>>>
>>>>> I was bit annoyed by the impossibility to debug scripts and packages
>>>>> run or installed from the command line.
>>>>> Therefore I added an option, ``-e <argument>``, that lets you
>>>>> set the exception class to handle before executing a script.
>>>>>
>>>>> With the attached change set, you can now write:
>>>>>
>>>>> squeak Cuis.image -e nil -s myScript.st
>>>>>
>>>>> If ``myScript.st`` contains an error, a Debugger
>>>>> will pop up.
>>>>>
>>>>>
>>>>> HTH and Best Regards,
>>>>>
>>>>> Gerald
>>>>>
>>>>
>>>
>>
>>
>
>


-- 
Juan Vuletich
cuis.st
github.com/jvuletich
researchgate.net/profile/Juan-Vuletich
independent.academia.edu/JuanVuletich
patents.justia.com/inventor/juan-manuel-vuletich
linkedin.com/in/juan-vuletich-75611b3
twitter.com/JuanVuletich

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