The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Software Development’ Category

batch file – SHIFT doesn’t affect %* – Stack Overflow

Posted by jpluimers on 2019/05/30

Quoting the answer in full because it so tremendously useful [WayBack] batch file – SHIFT doesn’t affect %* – Stack Overflow.

Especially the quoting/dequoting bits and the clever trick reconstructing %* into a batch file variable (minus double spaces).

Thanks so much James-K!

As you know, shift has no effect on %*, but you can construct a %* equivalent.

We’ll call the following line.bat :

@echo off
set line=%1
:loop
shift
if not "%1"=="" (
  set line=%line% %1
  goto :loop
)

echo   %%* = %*
echo line = %line%

If you type in the following command (Notice the double space between 3 and 4) :

line 1 2 3  4 bla dee dah

You will get the following output :

  %* = 1 2 3  4 bla dee dah
line = 1 2 3 4 bla dee dah

Note that %* retains multiple spaces, while using the %n notation does not.


Using something like this, you can allow your users to put their parameters in any order.

:loop
  :: Single variable parameters
  if "%1"=="something" set something=true
  :: Multi variable parameters 
  if "%~1"=="/source" shift & set source=%1
  shift
if not "%~1"=="" goto :loop

Notice that in the Multi-variable parameter statement I include one shift statement and one setstatement separated by an ampersand (&). The & tells the command processor that a separate command to be executed follows.


EDIT:

FYI: I recommend double quotes when checking the contents of variables. Usually you can use anycharacter, and you don’t even need to use two because they are just there to insure that an empty variable does not cause an error. For instance, when %1 is empty and you do if not hello==%1 call :sub the command processor will see this if not hello== call :sub and compare hello to call then try to execute :sub, and throw an error. In that specific case if not xhello==x%1 call :sub is just as good as if not "hello"=="%1" call :sub, because an empty %1 will cause the command processor to see if not xhello==x call :sub.

BUT using characters other than double-quotes will cause problems if the variable contains any special characters.

Using brackets as variable delimiters like (%1) can cause problems. For instance, the (special) piping characters don’t play nice inside brackets, and the escape character just seems to disappear, neither acting as a normal character, nor as the escape-character.

Also brackets are special characters in and of themselves designed to group and/or separate different lines of code and may not always act as anticipated.

Lastly, double quotes themselves are special characters specifically designed to surround other special characters, allowing them to act as normal characters. This is why you may see variables unquoted, then quoted again, like so.

set var="%~1"  & REM This sort of thing is used to insure that a variable is quoted.
                 REM %~1 unquotes %1 if it is already quoted, and leaves it alone if
                 REM %1 is not quoted.

set "var=%~1"  & REM This code assumes that `%1` contains special characters and
                 REM like before unquotes a quoted %1, but leaves the variable itself
                 REM unquoted. The double-quotes surrounding the variable and data
                 REM protects the command processor from any special characters that
                 REM exist in the data. Remember that anytime you reference `%var%`,
                 REM you will need to also surround the variable and data with
                 REM double-quotes.

A quick check for quotes is if exist %1 if %1==%~1 echo Unquoted.

–jeroen

Posted in Batch-Files, Development, Scripting, Software Development | Leave a Comment »

delphi – Sorting TDictionary by a key of Integer in ascending order – Stack Overflow

Posted by jpluimers on 2019/05/30

Great answer on [WayBackdelphi – Sorting TDictionary by a key of Integer in ascending order – Stack Overflow by J… comes down to this:

var
  LDictionary : TDictionary<Integer, string>;
  LArray : TArray<Integer>;
...
  LArray := LDictionary.Keys.ToArray();
  TArray.Sort<Integer>(LArray);

I was trying the wrong direction (functional approach like LArray := LDictionary.Keys.ToArray.Sort(); ), but the above procedural solution works.

Members used:

–jeroen

Posted in Delphi, Development, Software Development | 1 Comment »

GExperts Help: Copy component names

Posted by jpluimers on 2019/05/29

I totally forgot this expert existed [WayBackGExperts Help: Copy component names

–jeroen

Posted in Delphi, Development, Software Development | Leave a Comment »

Conference Call Bingo – E Gilliam

Posted by jpluimers on 2019/05/29

Cool: [WayBack] Conference Call Bingo

Via: [WayBack] Conference Call Bingo Origin: https://www.facebook.com/photo.php?fbid=10213521201006095 – Lars Fosdal – Google+

–jeroen

Posted in Development, Software Development | Leave a Comment »

TInterlocked.Exchange for interfaces?

Posted by jpluimers on 2019/05/29

Via [WayBack] TInterlocked.Exchange for interfaces? Since there is no System.SyncObjs.TInterlocked.Exchange overload for interfaces (and the Exchange versio… – Stefan Glienke – Google+

It has made it to this piece in [Archive.issglienke / Spring4D / source / Source / Reactive / Spring.Reactive.pas — Bitbucket:

class function TInterlockedHelper.Exchange<T>(var Target: T;
  const Value: T): T;
begin
  Result := Default(T);
  PPointer(@Result)^ := Exchange(PPointer(@Target)^, PPointer(@Value)^);
  if Assigned(Value) then
    Value._AddRef;
end;

It is similar to the TInterlocked.Exchange methods.

–jeroen

 

Posted in Delphi, Development, Software Development | Leave a Comment »

IDE Fix Pack 5.92 keyboard binding for finding references

Posted by jpluimers on 2019/05/28

Since I keep forgetting this piece of IDE Fix Pack 5.92 released – DelphiFeeds.com

The new version 5.92 now binds

  • Ctrl+Alt+Enter to “Find References” and introduces
  • Shift+Ctrl+Alt+Enter for “Find Local References”.

No shortcut toggling anymore.

–jeroen

Posted in Delphi, Development, Software Development | Leave a Comment »

Clean Code is a team sport! – writeabout.net

Posted by jpluimers on 2019/05/28

Recommended read: [WayBackClean Code is a team sport! – writeabout.net.

The picture is of a developer journey taking years to go from fresh to seasoned ending up at exactly the same code: over time learning the sweet spot of coding.

The story continues correlating that journey to handling technical debt and finding the sweet spot between that and business value.

via:

–jeroen

Twitter

 

 

Posted in Agile, Code Quality, Code Review, Development, Software Development | Leave a Comment »

Starting points for JSON unmarshaller, that applies a JSON string to an existing object…

Posted by jpluimers on 2019/05/28

Interesting subject: [WayBack] I am looking for a JSON unmarshaller, that takes the JSON string and apply it to the object (and not take an object and try to apply the JSON to it). E… – Nicholas Ring – Google+

A start by Stefan Glienke: [WayBackJsonDataObjectUnmarshall — Bitbucket

–jeroen

Posted in Delphi, Development, Software Development | Leave a Comment »

The red zone, is why you want immutable constructs

Posted by jpluimers on 2019/05/23

Most code I come across is in the red zone, exactly depicting why you want immutable constructs. Immutable constructs will never end-up in the red zone.

Image: [WayBackWayback Machine.

The red zone is just one quadrant on the mutability/shareability diagram and getting outside that red zone quadrant is key.

With processor cores now becoming ubiquitous: you cannot get outside of the “Shard” half, so you have to get outside of the “Mutable” half.

Explaining the why and how, is part of a few presentations that Kevlin Henney gave:

Related YouTube videos are below.

–jeroen

Read the rest of this entry »

Posted in Conference Topics, Conferences, Development, Event, Multi-Threading / Concurrency, Software Development | Leave a Comment »

Scheduled jobs and jitter…

Posted by jpluimers on 2019/05/23

Too bad G+ doesn’t allow the WayBack machine or Archive.is to archive the whole thread at [WayBack] [Archive.isDas es inzwischen fast überall Standard ist die Uhren mit einem guten Zeitsignal zu synchronisiseren (NTP, DCF-77, GPS etc) ist eigentlich eine gute Sache… – Kristian Köhntopp – Google+ so here are a few quotes below.

The generatel conclusions seem to be that:

This was the start:
Nils Ketelsen originally shared:

Guckt man live sieht es schon anders aus: Während die RunQueue meist so bei 4-5 liegt (bei 21vCPUs kein Problem) springt sie jede volle Minute einige Sekunden lang auf 20. Bei durch 2 Teilbaren Minuten auf ca. 40. Bei durch 10 Teilbaren Minuten auf 70, bei durch 15 teilbaren Minuten auf 150…. Ich habe eben durch einen schlecht getimten Toilettenbesuch die volle Stunde verpasst, das muss ich gleich mal anders hinbekommen, aber ich gehe davon aus, daß es da noch schlimmer ist.

And these some of the comments:

Read the rest of this entry »

Posted in *nix, *nix-tools, Algorithms, cron, Development, Power User, Software Development | Leave a Comment »