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I have a system of where a .tex is generated from a program. The final .tex file has a (simplified) structure like this:



Now - when compiling this with pdflatex it complains at \PlotFrame{File_n.png} statements; because of the underscore. Unfortunately I do not have control over the filenames. Any suggestions of how I could keep the current structure with the \PlotFrame{} command - and let it accept arguments with underscore?

I would strongly prefer not having to escape it with \_.

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Welcome to TeX.sx! You don't have to sign with your name since it automatically appears in the lower right corner of your post. – Werner Aug 28 '12 at 14:07
For me, underscores in filenames work without problems. Can you post a Minimal Working Example? – Sašo Živanović Aug 28 '12 at 14:28
In a minimal example with your code I get the image even if the name contains an underscore. Please, add a real example of something that causes the error. It probably has to do with printing the file name, rather than including the file. – egreg Aug 28 '12 at 15:16
Ahhh - this was embarassing; it turns out the problem was not with filename as such - but the figure caption which basically said: \caption{File: #1} – Joakim Hove Aug 28 '12 at 15:23
up vote 9 down vote accepted

You can define an additional macro like this:







\[ a_b \]


This will temporarily change the catcode for _ in the argument.

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The solution based on \catcode worked - thanks a lot! – Joakim Hove Aug 28 '12 at 15:12

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