从第二个单词开始的文件行中的总和-C编程

Question

Here is my input:

 david 10 40 70
 sam 9 45 31
 miranda 10 20 50
 zhang 10 26 41

I am trying to add all these numbers for each line and then print them out in terminal like this:

david 120
sam 85
etc...

how do I sum these numbers starting from the second word in a line? Here's my code for some context:

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 FILE *fr;
 char * line = NULL;
 size_t len =0;
 ssize_t read;

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

    fr = fopen(argv[1], "r");
        if(fr==NULL){
            exit(EXIT_FAILURE);
        }

         while ((read = getline(&line, &len, fr)) != -1){
            printf("%s", line );
        }
        fclose(fr);
        if (line){free(line);}
    return 0;
 }

Answer 1

You could try strsplit() ( EDIT : Or strtok() as @1.618 suggests, a bit different that PHP's strsplit) for each line, and then use atoi() .

I'm not sure that strsplit() exists in C standard libraries, you may have to recode it yourself : it takes a char * (your string to split) and a char (the delimiter, in this case a space), and should return a char ** in which are your substrings (the words) you could pass to atoi() .

Answer 2

If your buffer is null terminated, you can do it in place, without special string splitting functions, and handle an arbitrary number of numbers.

int sumline(char *buf)
{
  int sum=0;
  size_t i;
  for(i=0; buf[i] != '\0'; i++)
  {
    if(buf[i] == ' ' && isdigit(buf[i+1]))
    {
      sum += atoi(buf+i+1);
    }
  }
  return sum;
}

Just iterate over the characters, and whenever you hit a space, run atoi on the string starting from the next character.