main func
Code:int main (int argc, char **argv) { int sum; if (argc < 3 ) return -1; else sum = argv[1] + argv[2]; printf("Sum is %c\n",sum); return 0; } If the executable name is "sum", then what would be the output of below command line execution? $ ./sum 3 4 Please explain the above code. And when we needed to pass argument to main func? And main function recieves parameters from where?
The main function recieves parameters from command line. If you are using Turbo C, then in Run there is an option Parameters from there you just pass parameters, in example you said 3,4.
Also, as much what I know char **argv is a array of pointers so its char *argv[]. You may confirm it from more experienced people here on forum.
With char *argv[], argv[0] is the name of your executable and parameters you pass are argv[1] and argv[2].
One more thing,in your case only two arguments are passed 3,4 so the condition if(argc<3) holds true. Hence it will return -1. If the initial if condition evaluates to false then the next statements will be executed, i.e 3 and 4 will be added, and its value will be stored in sum.
Last edited by RajeshHB; 11-16-2010 at 03:12 AM.
command line means. Pls give one ex.
What are you trying to do here?Code:sum = argv[1] + argv[2];
The type of argv[i] is pointer to char.
This code SHOULD NOT even compile....
Bayint is right. Use strtol() to convert from the string to a number.
1. Get rid of gets(). Never ever ever use it again. Replace it with fgets() and use that instead.
2. Get rid of void main and replace it with int main(void) and return 0 at the end of the function.
3. Get rid of conio.h and other antiquated DOS crap headers.
4. Don't cast the return value of malloc, even if you always always always make sure that stdlib.h is included.
The first step would be to get a compiler which generates several error message in response to that code.
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
