Objective C Reading Complete File To String - ios

Question

I'm trying to make a file manager for iOS (my code has an exploit built in so it works).
The main code for my application is written in Swift and the code for running the exploit and reading files is written in Objecive-C.
This is the code I'm currently using in Objective-C:
NSString* readFile(NSString* file) {
char* buffer;
long lSize;
char* convertedFileName = [file UTF8String];
char* newFileName = deleteLastChar(convertedFileName); >> removes last / from path
char ch;
FILE *fp=fopen(newFileName, "r");
fseek( fp , 0L , SEEK_END);
lSize = ftell( fp );
rewind( fp );
buffer = calloc( 1, lSize+1 );
if( !buffer ) fclose(fp),fputs("memory alloc fails",stderr),exit(1);
if( 1!=fread( buffer , lSize, 1 , fp) )
fclose(fp),free(buffer),fputs("entire read fails",stderr),exit(1);
printf(buffer);
fclose(fp);
return [[NSString alloc] initWithUTF8String:buffer];
}
And this is the code for Swift:
func openFile(file: String) {
let fileContents = readFile(file)
print(fileContents) >> outputs nil
}
This is an example of a file I'm trying to open (plist file):
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>canvas_height</key>
<integer>1136</integer>
<key>canvas_width</key>
<integer>640</integer>
</dict>
</plist>
This is what the printf in the Objective-C code returns:
bplist00\322]canvas_height\canvas_width\240\332
(+
And Swift says the string is nil
The file is being read but there is still something wrong. Any ideas on how to fix this or a better way to handle this?