Question

I am reading the data from a file and I need to extract only integers from the below data.How do I accomplish it? Thanks.

My input will be field6 and I need to remove these characters “];” and store it in an integer variable.

My code:-

field6 = strtok(NULL," ");
if (isdigit(field6))
{
   weight = atoi (field6);
   printf("%d\n",weight);
}

Input:

43];
2];
4];
16];
25];

Output:

43
2
4
16
25

Answer 1

Without sscanf then:

#include <stdio.h>

int main(int argc, char** argv)
{
  const char *test = "123];";

  int i = 0;

  const char *p = test;
  while (*p && isdigit(*p))
  {
    if (p != test) i *= 10;
    i += *p - '0';
    ++p;
  }

  if (*p != ']')
  {
    // we have an error!
    return 1;
  }

  printf("%i\n", i);
}