I have a function which, given a filename and directory path, checks if the directory already contains a file with the same name and if so returns an amended filename (by appending a number after the first part of the filename). (The get_filenames() function is a CodeIgniter helper function which creates an array of all the filenames in the specified directory.)
When I try to print out the returned result of the function call, I get nothing; but if I print $new_filename in the else{} statement of the function itself, then simply call the function (rather than printing it's value), it works!
I need to return the value in the function, not print it, as I actually need to assign the result to a variable for further processing. (In the example below I've just printed the result of the function call to demonstrate the point.)
The function:
function avoid_conflicting_filenames($old_filename, $new_filename, $dir, $count)
{
$num = '';
if ($count > 0):
$num = $count;
endif;
$filename_arr = explode('.', $old_filename, -1);
$new_filename = $filename_arr[0] . $num . '.' . $filename_arr[1];
if (in_array($new_filename, get_filenames($dir))):
$count++;
avoid_conflicting_filenames($old_filename, $new_filename, $dir, $count);
else:
return $new_filename;
endif;
}
And where I call the function:
print avoid_conflicting_filenames('file.jpg', '', 'path/to/file', 0);
This has been driving me insane for the past day, so any help would be greatly appreciated! Thanks.
Replace this:
avoid_conflicting_filenames($old_filename, $new_filename, $dir, $count);
With this:
return avoid_conflicting_filenames($old_filename, $new_filename, $dir, $count);
You're not thinking about it recursively. You have to return the function's return value.
Past that, what's up with the if syntax? I tolerate it inside templates, but for code? ew.
If I'm understanding the code correctly, you could also rewrite this function to avoid recursion like so:
function avoid_conflicting_filenames($old_filename, $new_filename, $dir) {
$num = 0;
$files = get_filenames($dir);
$filename_arr = explode('.', $old_filename, -1);
do {
$new_filename = $filename_arr[0] . $num . '.' . $filename_arr[1];
$num++;
} while(in_array($new_filename, $files));
return $new_filename;
}
I think this is nicer and a little bit easier to get, but it's up to you...
Change your code to:
function avoid_conflicting_filenames($old_filename, $new_filename, $dir, $count)
{
$num = '';
if ($count > 0):
$num = $count;
endif;
$filename_arr = explode('.', $old_filename, -1);
$new_filename = $filename_arr[0] . $num . '.' . $filename_arr[1];
if (in_array($new_filename, get_filenames($dir))):
$count++;
return avoid_conflicting_filenames($old_filename, $new_filename, $dir, $count);
else:
return $new_filename;
endif;
}
You forgotten the return statment when calling avoid_conflicting_filenames inside of avoid_conflicting_filenames.
You're running the function recursively. You will need to pass the result on to the "parent" instance of the function:
if (in_array($new_filename, get_filenames($dir))):
$count++;
// Note "return" statement below.
return avoid_conflicting_filenames($old_filename, $new_filename, $dir, $count);
else:
return $new_filename;
endif;
If the first branch in your second if is taken the function never encounters a return statement.
Change it to read:
if (in_array($new_filename, get_filenames($dir))):
$count++;
//Added return
return avoid_conflicting_filenames($old_filename, $new_filename, $dir, $count);
else:
return $new_filename;
endif;
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