Write a program to create a mmap() that is shared by multiple threads. Use fstat() to obtain the size of the mapped file to size the mapping. Find out the number of logical processors (or cores) available programmatically by calling sysconf(), as shown, and display this number.

int numCPU = sysconf(_SC_NPROCESSORS_ONLN);

For this exercise, however, you are going to create four (4) threads only. Every thread should see the mapping. Each thread will display separate partial contents (sb.st_size/4 bytes) of the file.

Finally, unmap and close the file.

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Programming Language: C

Programming Environement: puTTy

Please make sure the program works in C before posting the answer!