Is this Ada textbook example rubbish? - ada

Question

Here are the sources for the example programs of "Ada for software engineers":
http://www.springer.com/cda/content/document/cda_downloaddocument/978-1-84882-313-6_programs.zip
after extracting go to c04-arrays/justify
$ gnatmake justify.adb
Run justify, and compare output with "example.txt" which is the input.
The output I get is has intertwined lines and has nothing to do with justification.
If I save the output with:
$ justify > result.txt
then looking at that I can conclude that some lines where written ontop of others in the terminal.
But even if I ignore that issue, the result can hardly be called justification.
My question:
Do you get the same unexpected output?
Does the output you get resemble justification?
Note that the input is also supplied with the source! So I am not even trying to break the program.
the output I get on the terminal:
The quicke quick brown fox jumped over the lazy dog.
brown fox jumped over the lazy dog.
ThequickbrownfoxjumpedoverthelazydogThequickbrownfoxjumpedov
The quickThe quick brown fox jumped over the lazy dog.
The quick brown foxed over the lazy dog.
The quick brown fox jumped over dog.
The quick brown fox jumped over the lazy
Thee slow gray wolf skipped over the frisky cat.
The slow grayray wolf skipped over the frisky cat.
The slow gray wolfed over the frisky cat.
The slow gray wolf skippedky cat.
The slow gray wolf skipped over the
The slow gray wolf skipped over the frisky
cat.
the output I have after redirection:
The quick brown fox jumped over the lazy dog.
The quick
brown fox jumped over the lazy dog.
ThequickbrownfoxjumpedoverthelazydogThequickbrownfoxjumpedov
The quick brown fox jumped over the lazy dog.
The quick
brown fox jumped over the lazy dog.
The quick brown fox
jumped over the lazy dog.
The quick brown fox jumped over
the lazy dog.
The quick brown fox jumped over the lazy
dog.
The slow gray wolf skipped over the frisky cat.
The
slow gray wolf skipped over the frisky cat.
The slow gray
wolf skipped over the frisky cat.
The slow gray wolf
skipped over the frisky cat.
The slow gray wolf skipped
over the frisky cat.
The slow gray wolf skipped over the
frisky cat.
The slow gray wolf skipped over the frisky
cat.
Is this supposed to be justification?
Is this problem related to my machine/system/terminal/shell in particular, or is the problem somewhere else?

Answer 1

I get the same output on Mac OS X.
The problem is that example.txt is a Windows file, with CR/LF line endings, and you're running on a Unix system, which expects just LF; and the Ada RTS is leaving the CR at the end of each input line. (I suspect the C RTS might do the same; Python handles it better).
Lots of info in Wikipedia, including that you can use cat -v to see the control characters:
The quick brown fox jumped over the lazy dog.^M The quick
brown fox jumped over the lazy dog.^M
ThequickbrownfoxjumpedoverthelazydogThequickbrownfoxjumpedov
The quick brown fox jumped over the lazy dog.^M The quick
brown fox jumped over the lazy dog.^M The quick brown fox
jumped over the lazy dog.^M The quick brown fox jumped over
the lazy dog.^M The quick brown fox jumped over the lazy
dog.^M The slow gray wolf skipped over the frisky cat.^M The
slow gray wolf skipped over the frisky cat.^M The slow gray
wolf skipped over the frisky cat.^M The slow gray wolf
skipped over the frisky cat.^M The slow gray wolf skipped
over the frisky cat.^M The slow gray wolf skipped over the
frisky cat.^M The slow gray wolf skipped over the frisky
cat.^M ^M
I don't know whether your system has a dos2unix utility, but in any case you can use tr:
$ tr -d '\r' <example.txt >example.lf
$ mv example.lf example.txt
Normally, you could have extracted the archive using unzip -a to convert line endings on all files that the original zip identified as text; in this case it identified all the files as binary, so you could use unzip -aa to force the conversion (given these are textbook examples, it's a fairly safe bet there won't be any actual binary files in there!)

Answer 2

The answer may be that your console is making tabs look like spaces, and thus giving different looking results.
You can test this with:
Ada.Text_IO.Put( ASCII.HT & '.' );
Ada.Text_IO.Put( ' ' & '.');
and see if the two periods are in the same column.