Thread: reading delimited input from file

I would like to know how to read input from a file that has this form:

lname,fname,city,state,phone.

I was thinking of using fscanf, except for that state could contain spaces and the different fields are separated by commas.

I want to load the data in and then display it some way like this:

Code:

main()
{
      FILE *fp = fopen("phonebk.txt","r");
      char lname[25],fname[25],city[25],state[25],phone[25];
      char buffer[80];
      fgets(buffer,80,fp);
      sscanf(buffer,"%s,%s,%s,%s,%s\n",lname,fname,city,state,phone);
      fclose(fp);
      printf("%s %s %s %s %s",lname,fname,city,state,phone);
      getch();
}

How would I use strtok to achieve what I want?

Code:

main()
{
      char lname[25],fname[25],city[25],state[25],phone[25];
      char buffer[80] = "Howard,Moe,Brooklyn,New York,000-0000";
      char *p;
      p = strtok(buffer,"'");
      printf("%s %s %s %s %s",lname,fname,city,state,phone);
      getch();
}

Here's how you'd use strtok(), with comments.

Code:

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

int main()
{
      char lname[25],fname[25],city[25],state[25],phone[25];
      char buffer[80] = "Howard,Moe,Brooklyn,New York,000-0000";

      /* for the first call, pass strtok the buffer and the delimiter */
      /* and remember to use strcpy() and not "="  */
      strcpy(lname, strtok(buffer,",");

      /* for the rest of the calls, pass it NULL and the delimiter */
      strcpy(fname, strtok( NULL, "," );
      strcpy(city, strtok( NULL, "," );
      strcpy(state, strtok( NULL, "," );
      /* Change the delimiter to "\n" for the end of the line */
      strcpy(phone, strtok( NULL, "\n" );

      printf("%s %s %s %s %s",lname,fname,city,state,phone);
      getch();

      return 0;
}

That should be right, then again it's very late and I just got off work



p.s. I'm not sure if strtok() is in string.h or stdlib.h, you might double check.

Something like

Code:

char *p;

p = strtok(buffer,",");
if ( p != NULL ) strcpy( lname, p );
p = strtok( NULL, ",");
if ( p != NULL ) strcpy( fname, p );
// etc

Though for extra safety, you should use strncpy to prevent possible overflows, or make lname, fname the same length as buffer.

> except for that state could contain spaces and the different fields are separated by commas.
This means you cannot use %s for the state

But you could do this

Code:

if ( sscanf ( buffer, "%s,%s,%s,%[^,],%s", lname, fname, city, state, phone) == 5 ) {
    // good data
} else {
    // bad data
}

The "%[^,]" is like %s, except it means all chars except comma