exit(0) vs exit(1) in C/C++ with Examples

exit is a jump statement in C/C++ language which takes an integer (zero or non zero) to represent different exit status.

There are two types of exit status in C/C++:

1. Exit Success: Exit Success is indicated by exit(0) statement which means successful termination of the program, i.e. program has been executed without any error or interrupt.

   #include <file.h>
   #include <stdio.h>
   
   int main()
   {
       FILE* file;
   
       // opening the file in read-only mode
       file = fopen("myFile.txt", "r");
   
       printf("File opening successful!");
   
       // EXIT_SUCCESS
       exit(0);
   }

   Note: Create a file called ‘myFile.txt’ and run the code in your local device to see the output.

2. Exit Failure: Exit Failure is indicated by exit(1) which means the abnormal termination of the program, i.e. some error or interrupt has occurred. We can use different integer other than 1 to indicate different types of errors.

   #include <file.h>
   #include <stdio.h>
   
   int main()
   {
       FILE* file;
   
       // open the file in read-only mode
       file = fopen("myFile.txt", "r");
   
       if (file == NULL) {
           printf("Error in opening file");
   
           // EXIT_FAILURE
           exit(1);
       }
   
       // EXIT_SUCCESS
       exit(0);
   }

Let’s see the differences between these two statements-

exit(0)	exit(1)
Reports the successful termination/completion of the program.	Reports the abnormal termination of the program.
Reports the termination when the program gets executed without any error.	Reports the termination when some error or interruption occurs during the execution of the program.
The syntax is exit(0);	The syntax is exit(1);
The usage of exit(0) is fully portable.	The usage of exit(1) is not portable.
The macro used for return code 0 is EXIT_SUCCESS	The macro used for return code 1 is EXIT_FAILURE
EXIT_SUCCESS is defined by the standard to be zero.	EXIT_FAILURE is not restricted by the standard to be one, but many systems do implement it as one.