Xcode，如何一次运行一个文件？

Question

Xcode Question, how to run one file at a time?

I keep getting this error: "Linker command failed with exit code 1" and I've noticed that it occurs when i use the "int main" method in multiple files. Furthermore, when I try to run a simple return 0 file, my "hello world" file still gives results to the console. So my assumption is that xcode is running all of the files in the project at the same time causing me to have a duplication error when I repeat method names (such as "int main"). How do I only run one file at a time? These are C files by the way, I'm using xcode as a tool to practice my c programming before next semester. Thanks for your help!

Answer 1

It sounds like you're trying to build multiple programs. The problem is you have a single "target" which is what Xcode uses to define what goes into an application.

You will need to create a separate target for each of your programs and assign target membership for your source files. Go to File->New->Target to create a new target. From the sounds of it, you are creating a command-line C program, so you will want to create a Command-Line Tool found under OS X-> Application .

Alternatively, you could also create separate projects for each program. See File->New->Program

As yet another alternative, assuming you are creating command-linen tools, if you wish you can use Xcode merely as an editor and build the program from the commandline (which you may have to do for your classes anyway). You can do this by creating your .c files and opening them in Xcode. Save the files to the same folder. To compile from the commandline, run something like the following in Terminal:

gcc -Wall file1.c file2.c -o myprogram

You would then run your program by giving:

./myprogram

If that doesn't work, make sure the command line tools are installed.

Answer 2

You can only have one int main per target.

You're getting linker errors because you're defining more than one.

If you need to run a function other than main at the start of execution, call it from main.

Answer 3

I ran into this issue myself following Learning C by Dan Gookin with exercise files. I learned that in order to be able to run the .c files, a project must be created then the files must be added specifying no target membership, otherwise Xcode will compile the entire files three as one executable and the errors encounter would prevent the program to run.