Add offset to line number (in error message) when using input files

Question

I am compiling a latex document, and when I have errors, I get nice messages like

l.1041 \end{frame}

which tells me that there is an error somewhere before line 1041. So far, so good. I can use my text editor and quickly find line 1041.

But sometimes I have a latex document (say, main.tex) that includes something like

\input{../my_headers}

at the beginning of the file. Now if latex tells me there is an error on line 1041, it is referring to the source code consisting of main.tex with my_headers.tex inserted into it. So if I edit the actual file main.tex, line 1041 doesn't correspond to the error location. The location I want is 1041 minus the number of lines in my_headers.tex.

So, I can manually calculate it, or make a script, but it seems like there must be a simple option to tell latex to ignore the input/include files when calculating line numbers.

Any ideas?

Answer 1

The number shown in the error message always refer to the line number in the file currently being read in, so there's no offset to compute.

Therefore, if a message such as

l.1041 \end{frame}

appears, it refers to the line number in the last file appearing in the log after an open parentheses (, in your case, probably

(./my_headers.tex

will be in the log some lines before the error message. If you launch the typesetting engine with the -file-line-error option, you'll get more informative messages, for example

./my_headers.tex:13: Undefined control sequence
l.13 \wronglytypedcommand

The call should thus be

pdflatex -file-line-error <other options> main

where <other options> may contain the usual options such as -synctex=1. How to add this option depends on the way the typesetting is launched from the front-end or editor.