| main() |
| The execution of a C program begins with function named main(). All of the files and |
| libraries for the C program are compiled together to build a single program file. That file |
| must contain exactly one main() function which the operating system uses as the starting |
| point for the program. Main() returns an int which, by convention, is 0 if the program |
| completed successfully and non-zero if the program exited due to some error condition. |
| This is just a convention which makes sense in shell oriented environments such as Unix |
| or DOS. |
