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

int get_word(char *buf, int buf_size, FILE *fp)
{ int len;
int ch;

while ((ch = getc(fp)) != EOF && !isalnum(ch)); /*←この !isalnum(ch) ってどういう意味ですか？*/
if (ch == EOF)
return EOF;
len = 0;
do {
buf[len] = ch;
len++;
if (len >= buf_size) {
fprintf(stderr, "word too long.\n");
exit(1); }
} while ((ch = getc(fp)) != EOF && isalnum(ch));
buf[len] = '\0';
return len; }

int main(void)
{ char buf[256];
while (get_word(buf, 256, stdin) != EOF) {
printf("<<%s>>\n", buf); }
return 0;
}