;; This buffer is for text that is not saved, and for Lisp evaluation.
;; To create a file, visit it with C-x C-f and enter text in its buffer.

   abc    def  	     ghi   -- three fields

abc;;;def -- four fields, middle two empty
;abc;	  -- three fields, outer ones empty


strtok(3) <string.h>

// whitespace separated fields
for (char *field = strtok(input, " \t"); field; field = strtok(NULL, " \t")) {
    // handle each field
}

strsep(3) <string.h>

// hard delimiters
char *field = input;
for (char *ip = input; true; ++ip) {
    if (*ip == '\0' || *ip == '\n') {
       // print chars field up to up
       break;
    }
    if (*ip == delim) {
       // print chars field up to ip
       field = ip + 1;
    }
}

char *field = NULL;
char delims[2] = { delim, '\0' };
while ((field = strsep(&input, delims)) != NULL) {
      // output field
}