从键盘输入一串字符,写进文件a.txt中,将其中小写字母转化为大写字母,然后输出到文件b.txt中保存,输入字符串以!结尾
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
int main()
{
char str[100];
FILE *fp;
int i=0;
fp=fopen("a.txt","w");
if(fp==NULL)
{
printf("error!");
exit(0);/*#include<stdlib.h>*/
}
gets(str);
while(str[i]!='!')
{
if(str[i]>='a'&&str[i]<='z')
str[i]-=32;
i++;
fputs(str,fp);
}
fclose(fp);
fp=fopen("b.txt","w");
fgets(str,strlen(str)+1,fp);
fclose(fp);
return 0;
}