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I'm trying to use Zbar which is a barcode reading library with bindings for different languages and environments. I'm trying to use Zbar with C++. I have written C++ code but I don't know much about importing libraries and setting up my IDE to do that. I'm using Xcode on macOS Sierra. Any guidance would be much appreciated.

EDIT: Thanks to the below answer, I was able to get ZBar installed successfully. However, when I try building the following code in Xcode:

#include <iostream>
#include <zbar.h>

int main(int argc, const char * argv[]) {        
    zbar::ImageScanner scanner;
    return 0;
}

I get the following error:

enter image description here

Carpetfizz
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1 Answers1

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I would recommend you use homebrew to manage all your packages on a Mac since Apple doesn't supply a package manager for some reason. You can grab it from brew.sh.

Once you have that installed, you can simply install zbar with:

brew install zbar

It would be a good idea to install pkgconfig too :

brew install pkgconfig

Now you can compile at the command line with:

clang yourProgram.c $(pkg-config --cflags --libs zbar) -o yourProg

or with C++, or g++:

clang++ yourProgram.cpp $(pkg-config --cflags --libs zbar) -o yourProg

If you want to use Xcode, you need to set up:

  • the search path for headers (include files)
  • the search path for libraries
  • the libraries themselves.

As they are not that simple to find, click on 1 then 2 in the figure below to get to the correct area of Xcode:

enter image description here

Now set them up like this:

enter image description here

enter image description here

And everything should be all good to go - as our American friends say. This method takes advantage of the fact that homebrew always puts symbolic links in /usr/local/include and /usr/local/lib to the latest, greatest version of zbar that you have installed. So, if you update any homebrew packages, your code will use the latest, greatest versions. You can see the links I am talking about like this:

ls -l /usr/local/include | grep zbar 
lrwxr-xr-x    1 mark  admin    34 13 Mar 12:15 zbar -> ../Cellar/zbar/0.10_4/include/zbar
lrwxr-xr-x    1 mark  admin    36 13 Mar 12:15 zbar.h -> ../Cellar/zbar/0.10_4/include/zbar.h

ls -l /usr/local/lib | grep zbar 
lrwxr-xr-x    1 mark  admin        41 13 Mar 12:15 libzbar.0.dylib -> ../Cellar/zbar/0.10_4/lib/libzbar.0.dylib
lrwxr-xr-x    1 mark  admin        35 13 Mar 12:15 libzbar.a -> ../Cellar/zbar/0.10_4/lib/libzbar.a
lrwxr-xr-x    1 mark  admin        39 13 Mar 12:15 libzbar.dylib -> ../Cellar/zbar/0.10_4/lib/libzbar.dylib

P.S. You update homebrew with:

brew update && brew upgrade

If you want to use a specific version of zbar, you need to work a little harder.

You get the include path like this:

pkg-config --cflags zbar

Sample Output

-I/usr/local/Cellar/zbar/0.10_4/include

And the library path like this:

pkg-config --libs zbar

Sample Output

-L/usr/local/Cellar/zbar/0.10_4/lib -lzbar

Then you put those values into Xcode along these lines:

enter image description here

Mark Setchell
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    Thank you SO much for the detailed answer, would never have been able to figure this out. I've updated the original post with a build error I'm getting when trying to compile a simple program using one of ZBar's classes. Would appreciate if you could take a look at it. – Carpetfizz Mar 12 '17 at 23:45
  • I pasted the output of `pkg-config --cflags zbar` in "Other Linker Flags" since the command had the word "flags" in it :) I'm beginning to think this is wrong. What should go in box 3 ? I used the outputs of the commands you provided for "Header Search Paths" and "Library Search Paths" (without the `-I` and `-L` ) – Carpetfizz Mar 12 '17 at 23:49
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    Please look again at the end of my answer - I had a moment to do it more thoroughly - sorry it was a rush last night! – Mark Setchell Mar 13 '17 at 09:20
  • Works perfectly, thank you so much! I want to learn more about the magic that you just walked me through - what's a good place to learn about C++ build processes (rather than just code) – Carpetfizz Mar 13 '17 at 14:13
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    Glad it worked for you. Not sure there is anything that describes all the old junk I know:-) Back in the old days, we used to learn `make` and have `Makefiles` for our command-line projects. Then `cmake` came along and made life easier. Then all the s/w development GUIs came along - Xcode, CLion, Eclipse, Visual Studio, NetBeans, Geany came along for folks who like graphical interfaces. Personally, I tend to use `cmake` and `git` but each to their own. You can Google the name of anything I have mentioned along with `tutorial` and you find something to get you started! – Mark Setchell Mar 13 '17 at 15:02
  • Great, thanks! I learned a little bit about make but (clearly) wasn't able to translate that knowledge to Xcode. Will check out CMake – Carpetfizz Mar 13 '17 at 15:04