I put together a macro to write the contents of an external file to the log output. Unfortunately, I always read out the trailing \par that LaTeX adds when reading files. How do I test for this and remove it? I am interested in the "TeX way", but all answers are welcome, of course.

The example macro deals with the following conditions:

• File is empty
• File has contents

It does not cover the following condition:

• File does not exist

In my example I do the following while compiling:

1. write to a file called functions-\jobname.txt (collects every mention of \myfunction in body)
2. read the file later functions-\jobname.txt
3. use typeout to put the contents of this file at the end of the log output (used for collaborated content-related debugging)

Read to Log Macro

I use \typeout to write to the log and terminal. I probably need to add some logic to my \readtolog macro to test for the trailing \par, so I extracted it from my working example below.

\newread\customfile\def\readtolog#1{%  \openin\customfile=#1\relax  \loop\unless\ifeof\file    \read\customfile to\fileline    \ifx\fileline\eolmarker    \else    \typeout{\fileline}    \fi  \repeat  \closein\customfile}

Example Code

\listfiles% used to illustrate atveryend which does not have much to do with the question\documentclass{article}\usepackage{fontspec}% compiled with xelatex\usepackage{regexpatch}% use for \xapptocmd\usepackage{etoolbox}% use for \tracingpatches\usepackage{atveryend}% Add support for \AtEndAfterFileList\newenvironment{logmessage}[1]{%  \typeout{^^J**************************************************^^J%  #1%  ^^J************************************************** }}  {\typeout{**************************************************}}\def\myfunction#1{#1}% Macro appended to by \xapptocmd\newread\customfile\def\readtolog#1{% LOGIC NEEDED TO REMOVE TRAILING \par  \openin\customfile=#1\relax  \loop\unless\ifeof\customfile    \read\customfile to\fileline    \ifx\fileline\eolmarker    \else    \typeout{\fileline}    \fi  \repeat  \closein\customfile}\def\checkfunctions{% Debug mode (enable writes and reads)  \tracingpatches  \newwrite\myfunctionsfile  \AtBeginDocument{\immediate\openout\myfunctionsfile=functions-\jobname.txt}  \AtEndDocument{\immediate\closeout\myfunctionsfile}  \AtEndAfterFileList{\begin{logmessage}{Functions}\readtolog{functions-\jobname.txt}\end{logmessage}}  \xapptocmd{\myfunction}{\immediate\write\myfunctionsfile{\unexpanded{##1}}}{}{}}\checkfunctions\begin{document}\myfunction{A function worth noting}\end{document}

Log Output Snippet

What is the deal with \par? Is this related? How to trim the end of line character for each line read from an external file?

**************************************************Functions************************************************** A function worth noting \par ************************************************** )