[eesmith]

Strings can point anywhere in the malloc'ed region:

  char buffer[] = "railroad";
  char *s = buffer;
  char *t = buffer + 4;
  printf("mult: %ld\n", strlen(s) * strlen(t));

Suppose I read 100 bytes, formatted as "{name}\t{rank}\t{serial number}\t" using variable length parts.

I can read the data into a single string buffer, replace the commas with NULs, and set up strings pointing to the middle of the buffer;

   typedef struct {char buf[101], char *name, char *rank, char *serialno} person;

   /* 100 bytes formatted as: name\trank\tserial no\t. */
   int read_data(FILE *f, person *p) {
     char *s;
     if (fread(p->buf, 1, 100, f) != 100) return -1;
     p->buf[100] = 0;
     p->name = p->buf;
     if ((s = strchr(p->buf, '\t') == NULL) return -2;
     *s = 0;
     p->rank = s+1;
     if ((s = strchr(s+1, '\t') == NULL)) return -2;
     *s = 0;
     p->serialno = s+1;
     if ((s = strchr(s+1, '\t') == NULL)) return -2;
     *s = 0;
     return 0;
   }

   person subject;
   if (read_data(stdin, &subject)) fail("cannot read.");
   print("Hello %s %s.\n", subject.rank, subject.name);
   ...

Even better, the protocol might have NUL characters already in the code, expecting C strings to point to the correct start.