Re: Text IO for files not using the standard line termination for the OS

[Keith Thompson <kst-u@mib.org>]

jdgressett@hotmail.com writes:
> I use Ada 2012 to write Windows programs; my usual compiler is 32-bit
> TDM-gcc which implements the gcc-5.1.0 version of the Ada compiler.
>
> My problem is a simple one: i need to produce a program which reads
> lines from a text file; if a line meets a requirement, it is written
> to an output file; if it does not meet the requirement it is not
> written to the output file.
>
> The annoyance that I must deal with is the fact that the files are not
> Windows text files, which use the <cr><lf> convention to terminate
> text lines.
>
> The files use a single <cr> as the line terminator.

That's unusual.  The most recent system system I know of that uses that
representation is pre-OSX MacOS.

> Is there a way to get Ada.Text_IO to use a line terminator that is not
> the default for the operation system on which the program runs?

There's no standard way to do it.  GNAT does provide some non-standard
Form parameters for Text_IO.Create and Text_IO.Open, but none of then do
just what you want.  ("Text_Translation=No" would let you handle
Unix-style text files on Windows, with line endings marked by <lf>.)

http://docs.adacore.com/live/wave/gnat_rm/html/gnat_rm/gnat_rm/the_implementation_of_standard_i_o.html#text-translation

Your best bet might be to translate the files before you feed them to
your program.  Or you can read the files in binary mode.

-- 
Keith Thompson (The_Other_Keith) kst@mib.org  <http://www.ghoti.net/~kst>
Will write code for food.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"