Command Line Arguments in C Language
Categories: C language
The arguments passed from command line are called command line arguments. These arguments are handled by main() function.To support command line argument, you need to change the structure of main() function as given below.
int main(int argc, char *argv[] )
Here, argc counts the number of arguments. It counts the file name as the first argument.
The argv[] contains the total number of arguments. The first argument is the file name always.
Example
Let's see the example of command line arguments where we are passing one argument with file name.
#include <stdio.h>
void main(int argc, char *argv[] ) {
printf("Program name is: %s\n", argv[0]);
if(argc < 2){
printf("No argument passed through command line.\n");
}
else{
printf("First argument is: %s\n", argv[1]);
}
}
Run this program as follows in Linux:
./program hello
Run this program as follows in Windows from command line:
program.exe hello
Output:
Program name is: program
First argument is: hello
If you pass many arguments, it will print only one.
./program hello c how r u
Output:
Program name is: program
First argument is: hello
But if you pass many arguments within double quote, all arguments will be treated as a single argument only.
./program "hello c how r u"