#include <stdio.h>
int main(int argc, char *argv[])
{
int a,b,sum;
if(argc!=3)
{
printf("please use \"prg_name value1 value2 \"\n");
return -1;
}
a = atoi(argv[1]);
b = atoi(argv[2]);
sum = a+b;
printf("Sum of %d, %d is: %d\n",a,b,sum);
return 0;
}
First run:
sh-4.2$ ./main 10 20
Sum of 10, 20 is: 30
Second run:
sh-4.2$ ./main 10 20 30 40
please use "prg_name value1 value2 "
As we have discussed in?command line argument?tutorial, that we can also give the input to the program through the?command line.
In this program, we will provide the input (two integer values) through the command line and program will add them and print the value of input numbers along with the sum of them.
Sample input
./main 10 20
Here,?./main?is the program's executable file name,?10?and?20?are the input values.
Sample output
Sum of 10, 20 is: 30
atoi()?is a library function that converts string to integer, when program gets the input from command line, string values transfer in the program, we have to convert them to integers (in this program).?atoi()?is used to return the integer of the string arguments.
First understand the algorithm carefully. Then study the program line-by-line and compare it with the output. Finally, review the explanation section to strengthen your logic and programming understanding.
Rewrite the program without looking at the code. Modify values, conditions or logic and run it again. This helps improve confidence and strengthens coding skills much faster.