How to read two words in one string

I have sample input file like this

1344 Muhammad Ayyubi 1
1344 Muhammad Ali Ayyubi 1

First, last number and surname are separated with tab character. However, a person may have two names. In that case, names are separated with whitespace.

I am trying to read from input file and store them in related variables.

Here is my code that successfully reads when a person has only one name.

fscanf(fp, "%d\t%s\t%s\t%d", &id, firstname, surname, &roomno)

The question is that is there any way to read the input file which may contain two first names.

Thanks in advance.

Solution

Read the line with fgets() which then saves that as a string.

Then parse the string. Save into adequate sized buffers.

Scanning with "\t", scans any number of white-space - zero or more. Use TABFMT below to scan 1 tab character.

Test results along the way.

This code uses " %n" to see that parsing reached that point and nothing more on the line.

#define LINE_N 100
char line[LINE_N];
int id, 
char firstname[LINE_N];
char surname[LINE_N];
int roomno;

if (fgets(line, sizeof line, fp)) {
  int n = 0;
  #define TABFMT "%*1[\t]"
  #define NAMEFMT "%[^\t]"
  sscanf(line, "%d" TABFMT NAMEFMT TABFMT NAMEFMT TABFMT "%d %n", 
      &id, firstname, surname, &roomno, &n);
  if (n == 0 || line[n]) {
    fprintf(stderr, "Failed to parse <%s>\n", line);
  } else {
    printf("Success: %d <%s> <%s> %d\n", id, firstname, surname, roomno);
  }
}

If the last name or first is empty, this code treats that as an error.

Alternate approach would read the line into a string and then use strcspn(), strchr() or strtok() to look for tabs to parse into the 4 sub-strings`.

The larger issue missed by OP is what to do about ill-formatted input? Error handling is often dismissed with "input will be well formed", yet in real life, bad input does happen and also is the crack the hackers look for. Defensive coding takes steps to validate input. Pedantic code would not use *scanf() at all, but instead fgets(), strcspn(), strspn(), strchr(), strtol() and test, test, test. This answer is a middle-of-the-road testing effort.