Makefile在Ubuntu/Linux的c++中编译OpenCV代码。

I am learning OpenCV using Learning OpenCV book.

我正在学习OpenCV学习OpenCV的书。

One problem I am facing while compiling the code is that I have to write a long command to compile and get the executable.

在编译代码时，我面临的一个问题是，我必须编写一个长命令来编译和获取可执行文件。

This is the command I am using

这是我正在使用的命令。

g++ `pkg-config –cflags opencv` file_name.cpp -o output_file `pkg-config –libs opencv`

I am no Make expert but I think I can eliminate writing that long command using make. Before that I should explain my work flow. I have created a directory called opencv in my home directory (~/opencv/). I am reading the book section by section and coding the examples or exercises into new cpp source code files in that directory. So I don't know the names of the files before hand.

我不是专家，但我想我可以消除使用Make的长命令。在此之前，我要解释一下我的工作流程。我在我的主目录中创建了一个名为opencv的目录(~/opencv/)。我正在逐节阅读书籍部分，并在该目录中将示例或练习编码到新的cpp源代码文件中。所以我之前不知道文件的名字。

Now what I want make to do is,

现在我要做的是，

Suppose I have coded a new file named facedetect.cpp in my opencv directory, and if I call make like this

假设我已经编写了一个名为facefind的新文件。在我的opencv目录中，如果我调用这样做。

make facedetect

then I want make to execute the following command for me

然后，我想让我执行下面的命令。

g++ `pkg-config --cflags opencv` facedetect.cpp -o facedetect `pkg-config --libs opencv`

so that whenever I make a new file named abc.cpp, I will execute make abc so that I can run

所以每当我创建一个新的文件，命名为abc。cpp，我会执行make abc，这样我就可以运行了。

$ ./abc

at my command line to test my abc.cpp

在我的命令行测试我的abc。

Please give that make file so that I can save the frustration of typing that long command each time.

请给出这个文件，这样我就可以节省每次输入长命令的挫败感。

PS: I have Googled for help on this and found this on using CMake but I could not understand what that does. Kindly also explain how can I use CMake for the same task.

PS:我用谷歌搜索了一下，发现这是用CMake的，但我不明白这是怎么回事。还请解释我如何使用CMake来完成同样的任务。

3 个解决方案

#1

You can create a file called Makefile in you working directory like this:

您可以在您的工作目录中创建一个名为Makefile的文件:

CFLAGS = `pkg-config --cflags opencv`
LIBS = `pkg-config --libs opencv`

% : %.cpp
        g++ $(CFLAGS) $(LIBS) -o $@ $<

then you can use this file for all your single-file programms. Just call make with the basename of the file you want to compile. For facedetect.cpp that would be

然后，您可以为所有的单文件程序使用此文件。只需调用要编译的文件的basename。facedetect。cpp这将是

make facedetect

Here some more details:

这里一些更多的细节:

The general format of a makefile is like this:

makefile的一般格式如下:

target : dependecy1 dependenc2 ...
    command that generates the target

So for your example you could write:

举个例子，你可以写:

facedetect : facedetect.cpp
    g++  $(CFLAGS) $(LIBS) -o facedetect facedetect.cpp

For each new example you can now create a new target. But you can also make it more general:

对于每个新示例，您现在可以创建一个新的目标。但是你也可以让它更一般化:

% : %.cpp
    g++  $(CFLAGS) $(LIBS) -o $@ $<

Here % matches any nonempty substring. The automatic variables $@ and $< substitute the names of the target file and the source file. For more information you can consult the make documentation.

这里%匹配任何非空的子字符串。自动变量$@和$ <替换目标文件和源文件的名称。有关更多信息，您可以查阅make文档。< p>

#2

GNU Make is pretty smart and the Makefile you need for this doesn't need to be as verbose as in the other answers given so far. Here is a simple Makefile which you can use to compile the OpenCV examples:

GNU Make非常聪明，您所需要的Makefile不需要像目前所给出的其他答案一样冗长。下面是一个简单的Makefile，可以用来编译OpenCV示例:

CPPFLAGS = $(shell pkg-config --cflags opencv)
LDLIBS = $(shell pkg-config --libs opencv)

That's it. The Makefile can be this short thanks to Make's implicit rules.

就是这样。Makefile可以是这个简短的感谢，因为它的隐含规则。

Then run make as usual:

然后像往常一样跑步:

make facedetect

This assumes there is a facedetect.c or facedetect.cpp in the same directory.

这假设有一个face检测。c或facedetect。cpp在同一个目录中。

I recommend the following (free!) book if you want to learn Make: http://oreilly.com/catalog/make3/book/index.csp

如果你想学习，我推荐以下(免费)书籍:http://oreilly.com/catalog/make3/book/index.csp。

#3

Create a file named makefile in your working directory that contains the following:

在工作目录中创建一个名为makefile的文件，该文件包含以下内容:

CFLAGS = $SHELL(pkg-config --cflags opencv)
LIBS = $SHELL(pkg-config --libs opencv)

facedetect : facedetect.cpp
    g++ $(CFLAGS) $(LIBS) -o $@ $<

Then when you want to compile you just type:

当你想编译时，你只需输入:

$ make

(To answer your PS - note that CMake is very different from make - for now you should probaby just use make.)

(回答你的PS -注意CMake和make是非常不同的，因为现在你应该使用make。)

#1