1.3.2 Program Startup
A program begins by calling the function main. There is no prototype required for this. It can be defined with no parameters such as:
int main(void) {
body…}
Or with the following two parameters:
int main(int argc, char *argv[]) {
body…}
Note that they do not have to be called argc
or argv
, but this is the common naming system.
argc
is a nonnegative integer. If argc
is greater than zero, then the string pointed to by argv[0]
is the name of the program. If argc
is greater than one, then the strings pointed to by argv[1]
through argv[argc-1]
are the parameters passed to the program by the system.
Example:
#include<stdio.h>
int main(int argc, char *argv[])
{
int loop;
if(argc>0)
printf("My program name is %s.\n",argv[0]);
if(argc>1)
{
for(loop=1;loop<argc;loop++)
printf("Parameter #%i is %s.\n",loop,argv[loop]);
}
}