Re: sed+windows/cygwin+newlines: improving documentation

[Eric Blake]

On 10/18/18 4:59 PM, Assaf Gordon wrote:
> Hello,
>
> On 12/10/18 12:01 PM, Eli Zaretskii wrote:
> > > From: Assaf Gordon <address@hidden>
> > >
> > > Do you think it would be better to also make "-b" affect STDIN/STDOUT?
> >
> > Yes, I think so.  It will allow to run on Windows Sed scripts that
> > remove CR characters, for example.
>
> Attached a patch to apply -b/--binary to STDIN/STDOUT under
> windows/mingw.
>
> comments (and testing) welcomed,
>   - assaf

> +++ b/doc/sed.texi
> @@ -363,8 +363,9 @@ to a non-empty value.
>   @opindex --binary
>   This option is available on every platform, but is only effective where the
>   operating system makes a distinction between text files and binary files.
> -When such a distinction is made---as is the case for MS-DOS, Windows,
> -Cygwin---text files are composed of lines separated by a carriage return
> +When such a distinction is made---as is the case for MS-DOS, Windows
> +(but not modern Cygwin)---text files are composed of lines separated by a
> +carriage return

Modern Cygwin still has the concept of text files, which have \r\n line 
endings. It is just that you have to specifically request them via mount 
options (they are not default).  So I don't think that excluding Cygwin 
is correct here.

>   @emph{and} a line feed character, and @command{sed} does not see the
>   ending CR.  When this option is specified, @command{sed} will open
>   input files in binary mode, thus not requesting this special processing
> @@ -344,6 +353,16 @@ main (int argc, char **argv)
>       }
>     check_final_program (the_program);
>   
> +#ifdef WINDOWS_BINARY_MODE_SUPPORT
> +  if (binary_mode)
> +    {
> +       if (_setmode ( _fileno (stdin), _O_BINARY) == -1)
> +         panic (_("failed to set binary mode on STDIN"));
> +       if (_setmode ( _fileno (stdout), _O_BINARY) == -1)
> +         panic (_("failed to set binary mode on STDOUT"));
> +    }

Isn't there a gnulib module for requesting setmode in a more portable 
manner?

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
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