Logging

Deutsch Software often contains a logging functionality. Usually entries one or sometimes multiple lines are appended to a file, written to syslog or to stdout, from where they are redirected into a file. They are telling us something about what the software is doing. Usually we can ignore all of it, but as soon as …

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Some thoughts about String equality

Of course Strings are today in some way Unicode. In this article we assume code points as the building blocks of Strings. That means for example in the Java-world, that we are talking about one code point being comprised of one Java character for typical European languages, using Latin, Greek or Cyrillic alphabets including extensions …

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Program Functionality without Code

Depending on the programming language and the frameworks we use, it is possible to have program functionality that is not happening in actual code that we write in that language. It seems weird, but actually it is something that we have been doing for decades and it has been sold to us as being extremely …

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Intervals

Intervals are subsets of a universe, that are defined by upper and lower boundaries. Typically we think about real numbers, but any totally ordered universe allows the definition of intervals. Intervals are defined by lower and upper boundaries, which can be a limiting number or unlimited, typically written as for the upper bound and for …

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LF and CR LF in git and svn

Typically we observe that line endings of text file turn out to be „linefeed“ (LF or „\n“ or 0x0a or Ctrl-J) on Linux and Unix-like systems (including MacOSX), while they are „carriage return and linefeed“ (CR LF or „\r\n“ or 0x0d 0x0a or Ctrl-M Ctrl-J) on MS-Windows. See the little obstacles of interoperability. This can …

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Word Documents vs. Wiki

It was this typical clash of cultures when a real IT guy, scientist, mathematician or engineer joined a company and suddenly an office package had to be used. It could have been any of them, think LibreOffice or MS-Office, but there were some others, that have meanwhile lost relevance. We liked to use text files …

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SQL: DROP, CREATE,… How to avoid errors?

In SQL we often want to create or drop an object (TABLE, VIEW, SEQUENCE, INDEX, SYNONYM, DATABASE, USER, SCHEMA,….) Now we do not know if this thing exists or not. We would like to write scripts, that work in either case. So something like CREATE TABLE IF NOT EXISTS XYZ (…); or DROP TABLE IF …

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Serialization

Deutsch Serialization allows us to store objects in a lossless way or to transfer them over the network. This could be done before, but it was necessary to program the serialization mechanism, which was a lot of work. Of course, they were not yet called objects in those days… Java suddenly had such a serialization …

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Why am I learning Python

To be honest, what can be done with Python can also be done with Perl or Ruby. I am not working in areas, where there is much better library support for Python than for Perl or Ruby. And I like Perl and Ruby very much and I am somewhat skeptical about Python. But there are …

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Meaningless Whitespace in Textfiles

We use different file formats that are more or less tolerant to certain changes. Most well known is white space in text files. In some programming languages white space (space, newline, carriage return, form feed, tabulator, vertical tab) has no meaning, as long as any whitespace is present. Examples for this are Java, Perl, Lisp …

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