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I want to manually add some header files like math.h and graphic.h for gcc but don't know where to put them.

Mateusz Piotrowski
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Chirag Soni
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2 Answers2

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First take a look in /usr/include or /usr/local/include.

If you find nothing there, try :

`gcc -print-prog-name=cc1plus` -v

This command asks gcc which C++ preprocessor it is using, and then asks that preprocessor where it looks for includes.

You will get a reliable answer for your specific setup.

Likewise, for the C preprocessor:

`gcc -print-prog-name=cc1` -v
Sachin S Kamath
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To look for header locations just use the locate command:

locate -b '\math.h'
locate -b '\graphics.h'

or a simpler approach

locate \*/math.h
locate \*/graphics.h

If you are more familiar with regular expression use

locate -r \/math.h$

To make sure the database is up-to-date start:

sudo updatedb

That's the way I'm searching my headers location. It's much faster than using the find command.

Finding headers in not installed packages

For sake of completeness I post a one liner script which is in my mind very useful in finding apt packages involving a special header file.

#!/usr/bin/env bash
apt-file search $1 | cut -f 1 -d ":" | sort -u

Save this one liner for instance in your ~/.local/bin directory as e.g. aptfilesearch and make it executable with chmod +x aptfilesearch. Now you get a list of all packages including the header file you are searching for. Here a simple demonstration:

aptfilesarch math.h
abu_bua
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  • math.h should already be present. Example : /usr/include/c++/7.3.0/math.h – Knud Larsen Apr 08 '18 at 13:21
  • How does the backslash act to prevent matching by files with preceding characters in their basename? The string \math.h should evaluate to math.h, but I see that \math.h avoids matching files like tgmath.h and quadmath.h. – user001 Dec 23 '19 at 00:31
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    FROM 'man locate' : To search for a file named exactly NAME (not *NAME*), use locate -b '\NAME' Because \ is a globbing character, this disables the implicit replacement of NAME by *NAME*. – abu_bua Dec 23 '19 at 00:43
  • Thanks. I had checked man locate, but I guess I have a different version of the locate(1) man page (which doesn't have one instance of \ ). – user001 Dec 23 '19 at 00:53
  • info locate or http://man7.org/linux/man-pages/man1/locate.1.html – abu_bua Dec 23 '19 at 13:09