CODEWITHSUNDEEP
ccommand-linecommand-line-arguments
Necrode
Necrode

Reputation: 51

Reading values from command line using flags

So I am attempting to read in values from the command land after a flag has been hit. I don't want to use scanf because it shouldn't pause. It should take in arguments as follows: run -p 60 10 Where 60 is a percentage value, and 10 is a number of processes. How does one go about reading those into variables without using scanf which pauses for user input? Do I need to assign them values using argv[2] and argv[3]? I want integer values, not strings.

This is my code so far:

#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <ctype.h>
#include <unistd.h>


bool Gamble(int percent);




int main(int argc, char *argv[])
{

int c;
int pflag = 0;
int vflag = 0;
int percent;
int processes;

while ((c = getopt (argc, argv, "-p-v: ")) != -1)
{
     switch (c)
       {
       case 'p':
         pflag = 1;
         percent = argv[2];
         //scanf("%d", &percent);
         break;
       case 'v':
         vflag = 1;
         break;
       default:
         processes = argv[3];
       }

}

printf("%d\n", percent);
printf("%d\n", processes);




Gamble(percent);


return 0;

}

P.S. Gamble is just a class that takes in the percentage, generates a random number, and returns "Success" or "Failure" based on whether or not the percentage passed is hit using the random generator.

Upvotes: 0

Views: 275

Answers (2)

Mike Makuch
Mike Makuch

Reputation: 1838

getopt puts the option values in optarg. You don't want to read them from argv[] directly.Ssee examples of how to use getopt

http://www.gnu.org/software/libc/manual/html_node/Example-of-Getopt.html

Upvotes: 1

Gavin Smith
Gavin Smith

Reputation: 3154

You can use sscanf to read a number value from a string.

Upvotes: 2

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