What should I do to get all the return value of a c-program from the command line?

Question

I have a simple C-program "./my_program"

 #include <stdio.h> int main (int argc , char **argv) { unsigned int return_result = 0x474; printf("return_result = %d = 0x%x \n",return_result,return_result); return return_result; } 

As a result, this program prints:

 return_result = 1140 = 0x474 

I want to get the return value of a c program in a bash script. According to this link Anyway, to get the return value of a c-program from the command line? Should I get this variable from $?

But when I run such commands, the result is:

 ./my_program echo $? 

I get

 116 

Obviously, 116 = 0x74 (low byte). But I would like to get all the value of unsigned int. What's wrong? What should I do to get all the return value of a c-program from the command line? This is not just about the type "unsigned int". What if I created a complex type, for example, a structure.

I tried this:

 return ((unsigned int) return_result_section_size); 

This does not work.

Answer 1

Unix exit codes are limited to one byte . If you want to output more, you can write it to stdout or to a file.

Then why is the standard C statement that main returns int , not char ? I have no idea...

Answer 2

The value returned from the main can be printed using echo $? after you finish execution. The return value from main is usually used to indicate execution status. The maximum value is limited to 512. If you try to return a larger value than 512, the value 512% val will be set to $ ?.