从资料流中读取一个单词的函数getword()的返回值为什么要这么设计
从文件流中读取一个单词的函数getword()的返回值为什么要这么设计？
Now for the function getword. We have written a more general getword than is necessary for this program, but it is not complicated. getword fetches the next ``word'' from the input, where a word is either a string of letters and digits beginning with a letter, or a single non−white space character. The function value is the first character of the word, or EOF for end of file, or the character itself if it is not alphabetic.
这是书上的代码：
我再贴上书上的主调函数吧：
Now for the function getword. We have written a more general getword than is necessary for this program, but it is not complicated. getword fetches the next ``word'' from the input, where a word is either a string of letters and digits beginning with a letter, or a single non−white space character. The function value is the first character of the word, or EOF for end of file, or the character itself if it is not alphabetic.
这是书上的代码：
// 返回值为什么要这么设计？
/* getword: get next word or character from input */
int getword(char *word, int lim)
{
int c, getch(void);
void ungetch(int);
char *w = word;
while (isspace(c = getch()))
;
if (c != EOF)
*w++ = c;
if (!isalpha(c))
{
*w = '\0';
return c;
}
for ( ; −−lim > 0; w++)
if (!isalnum(*w = getch()))
{
ungetch(*w);
break;
}
*w = '\0';
return word[0];
}
我再贴上书上的主调函数吧：
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#define MAXWORD 100
int getword(char *, int);
int binsearch(char *, struct key *, int);
/* count C keywords */
main()
{
int n;
char word[MAXWORD];
while (getword(word, MAXWORD) != EOF)
if (isalpha(word[0]))
if ((n = binsearch(word, keytab, NKEYS)) >= 0)