编译器练习：将C程序中的注释中的小写字母转换为大写字母

/*filename:notes.c
programed by:alex shoal
edit date:2009-2-9
revision:1
****************
reference:
"compiler construction principles and practice"
page 42~43 DFA design
****************
*/
#include <stdio.h>
#include <stdlib.h> // ANSI C exit() prototype
int is_lowercase(int);
int is_uppercase(int);

int main(int argc, char *argv[])

{

int ch; // place to store each character as read
int state=0;
FILE *fp; // "file pointer"
if (argc != 2){
printf("Usage: %s filename/n", argv[0]);
exit(1);
}
if ((fp = fopen(argv[1], "r")) == NULL){
printf("Can't open %s/n", argv[1]);
exit(1);
}

while (((ch = getc(fp)) != EOF)){
switch(state){
case 0:{ if(ch=='/') state=1; break; }
case 1:{ switch(ch){
case '*': state=2;break;
case '/': state=4;break;
default : state=0;break;
}
break;
}
case 2:{ if(ch=='*') state=3;break; }
case 3:{ if(ch=='/') state=0;else state=2;}
case 4:{ if(ch==10 ) state=0;} //if ch == '/n', exit
}
if(is_lowercase(ch)==1&&(state==2||state==4))
putc(ch-32,stdout);
else putc(ch,stdout);
}
fclose(fp);
return 0;
}

int is_lowercase(int ch){
if (ch>=97&&ch<=122)
return 1;
else return 0;
}

int is_uppercase(int ch){
if (ch>=65&&ch<=90)
return 1;
else return 0;
}