thanks for your reply. "it fails" means the file was created but was empty.I realized that the file d:\\a.jpg doesn't exist there before the program runs,now i created it then execute the program,it successed. however,i can't understand my book says "a" will create a file when the file doesn't exist,campare with "w",:confused:why it produces different result?

I wrote the code below to copy a picture,and why it will fail if i change the mode of fdest to "ab"? "ab" means write and add to file,isn't it?what's the difference?

#include<stdlib.h>
#include<stdio.h>

#define MAX 1024
int
main(int argc,int **argv){

FILE \*fsource,\*fdest;
size\_t in;
int buf\[MAX\];
fsource = fopen("F:\\\\a.jpg.rar","rb");
fdest = fopen("D:\\\\a.jpg","wb");
if(fsource == NULL || fdest == NULL)
	perror("open error");

while((in = fread(buf,sizeof(int),MAX,fsource)) != 0){
	fwrite(buf,sizeof(int),in,fdest);
	fflush(fdest);
}

fclose(fsource);
fclose(fdest);

return EXIT\_SUCCESS;

}

modified on Saturday, October 17, 2009 5:49 AM

It can't be discribed in a word,maybe the book named Learning Perl will help you ;)

well,everybody,I said C~~maybe you should tell me something likes GTK library,any others?I know GTK only... ;P ;P

I'm a rookie to C and i'm looking for some libraries to learn,something likes the C++ STL or Boost ,does any1 can tell me some of them?Thanks a lot Eric