C Primer Plus（第六版）13.11 编程练习 第1题

#include <stdio.h>

#include <stdlib.h>

// 13.10-4.txt

int main()

{

int ch;

FILE *fp;

unsigned long count = 0;

char file_name[30];

char str[30];

printf("文件名:\n");

scanf("%s",file_name);

if ((fp = fopen(file_name, "a+")) == NULL)

{

printf("Can't open %s\n", file_name);

exit(EXIT_FAILURE);

}

printf("需要添加的信息(ctrl+z结束):");

while(scanf("%s",str) != EOF)

{

fprintf(fp, "%s", str);

}

fseek(fp, 0L, SEEK_SET);

while ((ch = getc(fp)) != EOF)

{

putc(ch,stdout);

count++;

}

fclose(fp);

printf("\nFile %s has %lu characters\n", file_name, count);

return 0;

}