wad wad - 1 year ago 67
C Question

How could I write a C program that takes an integer from command line?

I want to write a C program that takes positive integer n from standard input, and outputs n+1. It is supposed to work like this

./myprog 3
--> returns 4

./myprog -2
--> crashes

I tried using scanf. But it does not take standard input from the command line. Any code template to help me out? Thanks.

Earlier, I also tried

#include <stdio.h>
int main( ) {

int c;

printf( "Enter a value :");
c = getchar( );

printf( "\nYou entered: ");
putchar( c );

return 0;

It does not give a command-line solution neither.

Answer Source
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char * argv[])
     int n = atoi(argv[1]); // n from command line
     n = n + 1; // return n + 1
     printf("%d", n);

     return 0;
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