Thread: Simple Error?

Code:

#include <stdio.h>

int main ()
{
  FILE * pFile;
  if( rename( "C:/test2", "C:/test1" ) != 0 )
    rename( "C:/test1", "C:/test2" );
    pFile = fopen ("C:/test1","w+");
    fputs ("1 2",pFile);
    fclose (pFile);
    puts( "Done." )
  else
    remove( "C:/test1" );
    rename( "C:/test2", "C:/test1" );
    puts( "Done." );
  return 0;

Compiling under PellesC, there are three build errors and I have no idea as to why...

error #2001: Syntax error: found 'else' - expecting ';'.
error #2157: Unrecognized statement.
error #2001: Syntax error: found 'remove' - expecting ';'.

Does anyone mind telling me where I went wrong in the syntax usage or pointing me in the correct direction? According to the two books I've read I have done nothing wrong so I'm stumped. Sorry to bother you all.

Thanks in advance.

Thank you very much zacs7, the code worked perfectly. I didn't know there needed to be to be braces between the if statements, I'm too used to pseudo :P

I now have a secondary error however, the program's initial part in which it renames the initial file is to see if it the file which is being renamed in-fact exists, this however doesn't seem to trigger an error and to my knowledge the rename function shouldn't give you "0" as a response if it fails to find the file which is to be renamed. Does anyone know how to combat this?

The return value of rename() is zero upon success, non-zero on error.
Kurt

Originally Posted by ZuK

The return value of rename() is zero upon success, non-zero on error.
Kurt

I just saw my mistake before I refreshed this thread :P Thank you very much however, you're all quite a lovely & helpful bunch.

Take care & my regards

Code:

	if(fopen("C:/test2", "r") != 0)

Don't unterstand what you try to do, but this fopen() call is not a good idea. You never store the returnvalue so you have no way to close the file, and I think you cannot rename an open file.
Kurt

Originally Posted by ZuK

Code:

	if(fopen("C:/test2", "r") != 0)

Don't unterstand what you try to do, but this fopen() call is not a good idea. You never store the returnvalue so you have no way to close the file, and I think you cannot rename an open file.
Kurt

Either way, it would end up going one way or another even though it wouldn't execute the renaming function. So before I can even consider that, I must get past the original IF statements.

Originally Posted by int3

Either way, it would end up going one way or another even though it wouldn't execute the renaming function. So before I can even consider that, I must get past the original IF statements.

fopen() returns nonzero on success.
your code is like

Code:

if ( open "test2" succeedes )
   rename "test1" to "test2"

Kurt

Originally Posted by ZuK

fopen() returns nonzero on success.
your code is like

Code:

if ( open "test2" succeedes )
   rename "test1" to "test2"

Kurt

I inverted the IF conditions and I still get the same issue.

Originally Posted by int3

I inverted the IF conditions and I still get the same issue.

Abd what is the issue ? ( and don't say it doesn't work )
Kurt

Originally Posted by ZuK

Abd what is the issue ? ( and don't say it doesn't work )
Kurt

The program initially looks to see if a backup of the file in question exists;

Code:

if(fopen("C:/test2", "r") != 0)

If one doesn't then a backup is made and a new one is made with certain text;

Code:

rename("C:/test1", "C:/test2");
pFile = fopen("C:/test1", "w+");
fputs("1 2", pFile);
fclose(pFile);
puts("Done.");

If a backup does exist then the backup is deleted & the original is restored;

Code:

remove( "C:/test1" );
rename( "C:/test2", "C:/test1" );
puts( "Done." );

I understand that your code is either like this

Code:

if(fopen("C:/test2", "r") != 0) {
        // test2 is open now
	rename("C:/test1", "C:/test2"); // this will fail ( cannot rename open file )
	pFile = fopen("C:/test1", "w+");
	fputs("1 2", pFile);
	fclose(pFile);
	puts("Done.");
} 
else {
        // test2 doesn't exist
	remove( "C:/test1" );        
	rename( "C:/test2", "C:/test1" ); // will fail because test2 doesn't exist
	puts( "Done." );
}

or like this

Code:

if(fopen("C:/test2", "r") == 0) {
        // test2 doesn't exist
	rename("C:/test1", "C:/test2"); 
	pFile = fopen("C:/test1", "w+"); // will fail because test1 has just be renamed to test2
	fputs("1 2", pFile);
	fclose(pFile);
	puts("Done.");
} 
else {
        // test2 is open
	remove( "C:/test1" );        
	rename( "C:/test2", "C:/test1" );// this will fail ( cannot rename open file )
	puts( "Done." );
}

if your actual version is different. post it.
Kurt

I posted the actual copy a few posts ago (#7)

http://cboard.cprogramming.com/showp...12&postcount=7

I'm already aware of the issues that I will have, I just can't seem to get past the initial IF sequence where it checks to see if the file even exists.