"Linking Error: Duplicate public_main in module" while building [closed] - c

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I have created a a simple file under one work area, build it and executed successfully. And again created another file under same work area. I am getting linking error like:
"====Linking===== Error: Duplicate public_main in module...." while building and I am getting the same error when I try to execute first file also.
Please see the below code and suggest.
File1: n_numbers.c
#define N 10
main()
{
int count;
float sum, number;
count=0;
sum=0;
printf("Enter 10 numbers to calculate the Sum");
while(N<10)
{
scanf("%f", &number);
sum=sum+number;
count=count+1;
}
printf("sum=5.2%", sum);
}
File2: two.numbers.c
main()
{
int a,b,c;
printf("Enter Two numbers for a and b\n");
scanf("%d %d",&a, &b);
c=a+b;
printf("c=%d", c);
}

Answer 1

I suspect your problem is:
gcc file_a.c
a.out
Works
gcc file_b.c
a.out
Works
gcc file_a.c file_b.c
linker error
Will be because gcc is trying to make a single executable and each executable must have exactly one main function.
If file_a and file_b both define a function called public_main the problem becomes which one is intended in any given invocation - C solves this by a simple rule - you can only have one of each function in each executable.
N.B. Other languages have different rules, C++ can have multiple functions with the same name but different prototypes, (overloading), or within different classes, (namespaces), it actually does both via what is called name mangling. Python uses namespaces and sophisticated scoping rules, etc.
Copied from comments!
Hi Steve, I had only one main() in each executable, but still i am
getting same error – user2714972
You have 2 .c files and you are linking them into a single executable,
(.exe), that is what gcc does when you give it more than one .c file
if you would like to make 2 executables you need to call gcc twice,
once with each .c and with -o differcent_exe_name to stop both being
called a.out or a.exe – Steve Barnes
If, as some have suggested, you are using an IDE you need to either create separate projects or specify separate targets depending on the IDE.