C++程序  |  32行  |  449 B

/*
 * fgets.c
 *
 * This will be very slow due to the implementation of getc(),
 * but we can't afford to drain characters we don't need from
 * the input.
 */

#include <stdio.h>

char *fgets(char *s, int n, FILE * f)
{
    int ch;
    char *p = s;

    while (n > 1) {
	ch = getc(f);
	if (ch == EOF) {
	    *p = '\0';
	    return (p == s) ? NULL : s;
	}
	*p++ = ch;
	if (ch == '\n')
	    break;
	n--;
    }
    if (n)
	*p = '\0';

    return s;
}