how to find the file given by #include?

This is a discussion on how to find the file given by #include? within the C++ Programming forums, part of the General Programming Boards category; hi guys It's about the beginning section of every code where you give the libraries I need a shortcut to ...

  1. #1
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    how to find the file given by #include?

    hi guys

    It's about the beginning section of every code where you give the libraries
    I need a shortcut to find some file given through #include<file.name> without searching though all header data.

    is there any way?

    Thanks

  2. #2
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    Your question is ambiguous.

    In code within an #include'd file, it is possible to find its filename (or, more accurately, a string that is representative of the filename) using the __FILE__ prefined macro (which is specified in the standard).

    From a source file that is #include'ing another files, each #include directive specifies the name of the file it is including. There is no way, within a source file, to write code to enumerate the files which that source file has #include'd.

    The only way is to use some other program (eg a program that searches files for a string) to externally search the source files for #include directives. Even that can be fooled, however, by conditional macro expansion (eg an #include directive surrounded by #ifdef ABC/#endif where ABC is not defined) or by the fact that the filename given to an #include directive can be the result of a macro expansion.

    I suspect your requirement is flawed (i.e. you're actually trying to do something else, and have somehow latched onto the idea of doing this in error).
    Last edited by grumpy; 03-25-2013 at 03:04 AM.
    Right 98% of the time, and don't care about the other 3%.

  3. #3
    and the hat of wrongness Salem's Avatar
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    Well you could do this
    Code:
    $ gcc -M foo.c
    foo.o: foo.c /usr/include/stdio.h /usr/include/features.h \
     /usr/include/x86_64-linux-gnu/bits/predefs.h \
     /usr/include/x86_64-linux-gnu/sys/cdefs.h \
     /usr/include/x86_64-linux-gnu/bits/wordsize.h \
     /usr/include/x86_64-linux-gnu/gnu/stubs.h \
     /usr/include/x86_64-linux-gnu/gnu/stubs-64.h \
     /usr/lib/gcc/x86_64-linux-gnu/4.6.1/include/stddef.h \
     /usr/include/x86_64-linux-gnu/bits/types.h \
     /usr/include/x86_64-linux-gnu/bits/typesizes.h /usr/include/libio.h \
     /usr/include/_G_config.h /usr/include/wchar.h \
     /usr/lib/gcc/x86_64-linux-gnu/4.6.1/include/stdarg.h \
     /usr/include/x86_64-linux-gnu/bits/stdio_lim.h \
     /usr/include/x86_64-linux-gnu/bits/sys_errlist.h \
     /usr/lib/gcc/x86_64-linux-gnu/4.6.1/include-fixed/limits.h \
     /usr/lib/gcc/x86_64-linux-gnu/4.6.1/include-fixed/syslimits.h \
     /usr/include/limits.h /usr/include/x86_64-linux-gnu/bits/posix1_lim.h \
     /usr/include/x86_64-linux-gnu/bits/local_lim.h \
     /usr/include/linux/limits.h \
     /usr/include/x86_64-linux-gnu/bits/posix2_lim.h
    Or this
    Code:
    $ gcc -E foo.c | awk '/^#/ && $3 ~ "/" { print $3 }' | sort -u
    "/usr/include/features.h"
    "/usr/include/_G_config.h"
    "/usr/include/libio.h"
    "/usr/include/limits.h"
    "/usr/include/linux/limits.h"
    "/usr/include/stdio.h"
    "/usr/include/wchar.h"
    "/usr/include/x86_64-linux-gnu/bits/local_lim.h"
    "/usr/include/x86_64-linux-gnu/bits/posix1_lim.h"
    "/usr/include/x86_64-linux-gnu/bits/posix2_lim.h"
    "/usr/include/x86_64-linux-gnu/bits/predefs.h"
    "/usr/include/x86_64-linux-gnu/bits/stdio_lim.h"
    "/usr/include/x86_64-linux-gnu/bits/sys_errlist.h"
    "/usr/include/x86_64-linux-gnu/bits/types.h"
    "/usr/include/x86_64-linux-gnu/bits/typesizes.h"
    "/usr/include/x86_64-linux-gnu/bits/wordsize.h"
    "/usr/include/x86_64-linux-gnu/gnu/stubs-64.h"
    "/usr/include/x86_64-linux-gnu/gnu/stubs.h"
    "/usr/include/x86_64-linux-gnu/sys/cdefs.h"
    "/usr/lib/gcc/x86_64-linux-gnu/4.6.1/include-fixed/limits.h"
    "/usr/lib/gcc/x86_64-linux-gnu/4.6.1/include-fixed/syslimits.h"
    "/usr/lib/gcc/x86_64-linux-gnu/4.6.1/include/stdarg.h"
    "/usr/lib/gcc/x86_64-linux-gnu/4.6.1/include/stddef.h"
    What's the chance that you're using some other compiler, but didn't think it was worth mentioning at the time.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
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