[OS X TeX] Single-stepping through TeX

[Doug McKenna]

Peter Dyballa wrote -

>Am 18.11.2011 um 20:47 schrieb Doug McKenna:
>
>> Although there's a directory in the distribution tree for web2c, I can't 
>> find any executables or sources or directions that make it easy (no doubt 
>> for some value of "easy") to convert TeX's source code into final 
>> runnable C code for the command line program "tex".
>
>There at least two source files: texk/web2c/tex.web and texk/web2c/tex.ch. 
>The former is the original and frozen source, the latter is a series of 
>patches.

Understood.  But there is no sub-directory named "texk" in the 
./texlive/2010/..." tree on my installation.  Nor is there one on the 
2011 CD I have.  Nor is there a "tex.ch" file on the 2011 CD, except 
going back quite a long time, to version 3.141.

Probably stored in an archive file, except I don't know what program 
decompresses them.

>Modern pdfTeX has texk/web2c/pdftexdir/pdftex.web and and also CHange 
>files, but it's actually based on eTeX, a series of patches for original 
>TeX, found in texk/web2c/etexdir. Here the file tex.ech visualises one 
>step of the build:
>
>	%	pdfetexdir/tex.ch0	)
>	%	   +			)
>	%	tex.ch			)
>	%	   +			)
>	%	etexdir/tex.ch1		)
>	%	   +			)   =>   tie -c ...   =>   pdfetex.ch
>	%	etexdir/tex.ech		)
>	%	   +			)
>	%	pdfetexdir/tex.ch1	)
>	%	   +			)
>	%	pdftexdir/tex.pch	)
>
>The cweave programme converts the WEB and CHange files to a TEX output 
>file, the documentation, the ctangle programme creates from the same input 
>a C output file. This can be compiled with a C compiler. But this is not 
>sufficient. You also need to compile libkpathsea.

Yeah, I got that impression.

>It might help to look into Fink or MacPorts. They have kind of "control 
>files" which make TeX Live build.

Thanks.


Doug McKenna