第 13 章 文件输入/输出 （标准I/O）

 1 /*--------------------------
 2     count.c -- 使用标准 I/O
 3 --------------------------*/
 4 
 5 #include <stdio.h>
 6 #include <stdlib.h>        //提供 exit() 函数原型
 7 
 8 int main(int argc, char *argv[])
 9 {
10     int ch;        //读取文件时，储存每个字符的地方
11     FILE *fp;    //文件指针
12     unsigned long count = 0;
13 
14     if (argc != 2)
15     {
16         printf("Usage: %s filename\n", argv[0]);
17         exit(EXIT_FAILURE);
18     }
19 
20     if (NULL == (fp = fopen(argv[1], "r")))
21     {
22         printf("Can't open %s\n", argv[1]);
23         exit(EXIT_FAILURE);
24     }
25 
26     while (EOF != (ch = getc(fp)))
27     {
28         putc(ch, stdout);        //同 putchar(ch)
29         ++count;
30     }
31 
32     fclose(fp);
33     printf("File %s has %lu characters\n", argv[1], count);
34 
35     return 0;
36 }