How do I access the fileModificationDate
NSString *docsDir = [NSHomeDirectory() stringByAppendingPathComponent:
#"TempiPad"];
NSFileManager *localFileManager=[[NSFileManager alloc] init];
NSDirectoryEnumerator *dirEnum =
[localFileManager enumeratorAtPath:docsDir];
NSString *file;
// List all files in docsDir
while (file = [dirEnum nextObject]) {
NSLog(#"File = %#",file);
NSError *attributesError = nil;
NSDictionary *fileAttributes = [[NSFileManager defaultManager] attributesOfItemAtPath:file error:&attributesError];
NSString *fileModificationDate = [fileAttributes objectForKey:NSFileModificationDate];
NSLog(#"ModDate = %#",fileModificationDate);
}
}
This just outputs (null). Eventually I will want to compare the fileModificationDate for two files, so how will I do that?
IIRC, you need to append the filename to the directory path; something like:
while (file = [dirEnum nextObject]) {
NSLog(#"File = %#",file);
NSError *attributesError = nil;
file = [docsDir stringByAppendingPathComponent:file];
NSDictionary *fileAttributes = [[NSFileManager defaultManager] attributesOfItemAtPath:file error:&attributesError];
NSDate *fileModificationDate = [fileAttributes objectForKey:NSFileModificationDate];
NSLog(#"ModDate = %#",fileModificationDate);
}
}
And, as more tension said, NSFileModificationDate is an NSDate, not an NSString.
NSFileModificationDate returns an NSDate instance, not an NSString. See:
NSFileModificationDate
Related
My json file look like this:
{
"images": [
"straight up kick.png",
"women kick.png",
"Taekwondo Kanji vertical.png",
"face kick3.png",
"flexibility.png",
"Punch.png",
"hook kick.png",
"front kick 2.png"
]
}
i am reading above json programmatically like below:
NSString *path = [[NSBundle mainBundle] pathForResource:#"generated" ofType:#"json"];
NSData *data = [NSData dataWithContentsOfFile:path];
NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
NSMutableArray * jsonimages = [dict objectForKey:#"images"];
NSLog(#"images %#", jsonimages);
i want to add more items to array named as jsonimages by writing to json file programmatically.
Json file name is generated.json.
Any help would be appreciated.
- (void)writeStringToFile:(NSString*)aString {
// Build the path, and create if needed.
NSString* filePath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString* fileName = #"generated.json";
NSString* fileAtPath = [filePath stringByAppendingPathComponent:fileName];
if (![[NSFileManager defaultManager] fileExistsAtPath:fileAtPath]) {
[[NSFileManager defaultManager] createFileAtPath:fileAtPath contents:nil attributes:nil];
}
// The main act...
[[aString dataUsingEncoding:NSUTF8StringEncoding] writeToFile:fileAtPath atomically:NO];
}
- (NSString*)readStringFromFile {
// Build the path...
NSString* filePath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString* fileName = #"generated.json";
NSString* fileAtPath = [filePath stringByAppendingPathComponent:fileName];
// The main act...
return [[NSString alloc] initWithData:[NSData dataWithContentsOfFile:fileAtPath] encoding:NSUTF8StringEncoding];
}
Hi I want to save an image to a directory, I pass the NSData and do what I think will save the file in a directory I create but the problem is that it doesn't save. This is what I have so far. Why doesn't the initWithContentsOfURL:encoding:error: work, it returns null but the other method I used works? The main problem is WRITETOURL which returns a 0 which i think means that the information wasn't stored properly, any tips?
NSFileManager *fm = [[NSFileManager alloc] init];
NSArray * directoryPaths = [fm URLsForDirectory:NSCachesDirectory inDomains:NSUserDomainMask];
NSLog(#"%#", directoryPaths);
NSURL* dirPath = nil;
dirPath = [[directoryPaths objectAtIndex:0] URLByAppendingPathComponent:[NSString stringWithFormat:#"photos.jpeg"]];
NSError* theError = nil;
[fm createDirectoryAtURL:dirPath withIntermediateDirectories:YES attributes:nil error:&theError];
UIImage* photoToStore = [UIImage imageWithData:photoToSave];
NSString *pathContainingPhoto = [[NSString alloc] initWithFormat:#"%#.jpeg", UIImageJPEGRepresentation(photoToStore, 1.0)];
NSError *error = nil;
BOOL OK = [pathContainingPhoto writeToURL:dirPath atomically:YES encoding:NSUTF8StringEncoding error:&error];
NSLog(#"OK = %d", OK); //Returns 0
NSLog(#"%#", dirPath);
//WHY DOESNT THIS VERSION WORK?
// NSString *pathToFile = [[NSString alloc] initWithContentsOfURL:dirPath encoding:NSUTF8StringEncoding error:&error];
NSLog(#"%#", pathToFile);
NSString* pathToFile = [NSString stringWithContentsOfURL:dirPath encoding:nil error:nil];
NSArray *dirContents = [fm contentsOfDirectoryAtPath:pathToFile error:nil];
NSLog(#"%#", dirContents);
Do like this and int count in .h file and set its intial value count = 0; in viewDidLoad:
NSString *stringPath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)objectAtIndex:0]stringByAppendingPathComponent:[NSString stringWithFormat:#"Image_%d.png",count];
error = nil;
if (![[NSFileManager defaultManager] fileExistsAtPath:stringPath]) // removing item it already exuts
{
[[NSFileManager defaultManager] removeItemAtPath:stringPath error:&error];
}
if(photoToSave) // nsdata of image that u have
{
[photoToSave writeToFile:stringPath atomically:YES];
}
count++; // maintaining count of images
my iPad app has a small download facility, for which I want to append the data using an NSFileHandle. The problem is the creation call only returns null file handles. What could be the problem? Here is the three lines of code that are supposed to create my file handle:
NSString *applicationDocumentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
self.finalPath = [applicationDocumentsDirectory stringByAppendingPathComponent: self.fileName];
NSFileHandle *output = [NSFileHandle fileHandleForWritingAtPath:self.finalPath];
I checked the file path, and I could see nothing wrong.
TYIA
fileHandleForWritingAtPath is not a “creation” call. The documentation explicitly states: “Return Value: The initialized file handle, or nil if no file exists at path” (emphasis added). If you wish to create the file if it does not exist, you’d have to use something like this:
NSFileHandle *output = [NSFileHandle fileHandleForWritingAtPath:self.finalPath];
if(output == nil) {
[[NSFileManager defaultManager] createFileAtPath:self.finalPath contents:nil attributes:nil];
output = [NSFileHandle fileHandleForWritingAtPath:self.finalPath];
}
If you want to append to the file if it already exists, use something like [output seekToEndOfFile]. Your complete code would then look as follows:
NSString *applicationDocumentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
self.finalPath = [applicationDocumentsDirectory stringByAppendingPathComponent: self.fileName];
NSFileHandle *output = [NSFileHandle fileHandleForWritingAtPath:self.finalPath];
if(output == nil) {
[[NSFileManager defaultManager] createFileAtPath:self.finalPath contents:nil attributes:nil];
output = [NSFileHandle fileHandleForWritingAtPath:self.finalPath];
} else {
[output seekToEndOfFile];
}
Get documents directory path
+(NSURL *)getDocumentsDirectoryPath
{
return [[[NSFileManager defaultManager]URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask]lastObject];
}
Save text to end of the file
if file doesnt exist create it and write data
+(void)saveText:(NSString *)textTobeSaved atPath:(NSString*)fileName
{
NSString *filePath = [NSString stringWithFormat:#"%#.text",fileName];
NSString *path = [[self getDocumentsDirectoryPath].path
stringByAppendingPathComponent:filePath];
NSFileHandle *fileHandler = [NSFileHandle fileHandleForWritingAtPath:path];
if(fileHandler == nil) {
[[NSFileManager defaultManager] createFileAtPath:path contents:nil attributes:nil];
fileHandler = [NSFileHandle fileHandleForWritingAtPath:path];
} else {
textTobeSaved = [NSString stringWithFormat:#"\n-----------------------\n %#",textTobeSaved];
[fileHandler seekToEndOfFile];
}
[fileHandler writeData:[textTobeSaved dataUsingEncoding:NSUTF8StringEncoding]];
[fileHandler closeFile];
}
get text from file with specified filename
+(NSString *)getTextFromFilePath:(NSString *)fileName
{
NSString *filePath = [NSString stringWithFormat:#"%#.text",fileName];
NSString *path = [[self getDocumentsDirectoryPath].path
stringByAppendingPathComponent:filePath];
NSLog(#"%#",path);
if(path!=nil)
{
NSString *savedString = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
return savedString;
}else{
return #"";
}
}
Delete file
+(void)deleteFile:(NSString *)fileName
{
NSString *filePath = [NSString stringWithFormat:#"%#.text",fileName];
NSString *path = [[self getDocumentsDirectoryPath].path
stringByAppendingPathComponent:filePath];
NSFileHandle *fileHandler = [NSFileHandle fileHandleForWritingAtPath:path];
if(fileHandler != nil) {
[[NSFileManager defaultManager]removeItemAtPath:path error:nil];
}
}
I'm currently using NSFileManager setAttributes to change the permission of a directory. My problem is that it doesn't appear to do so recursively. Is there any way to force it to do so?
I don't think there's a built-in method to do this, but it shouldn't be hard to do something like:
NSString *path = #"/The/root/directory";
NSDictionary *attributes; // Assume that this is already setup
NSFileManager *fileManager = [NSFileManager defaultManager];
NSArray *subPaths = [fileManager subpathsAtPath:path];
for (NSString *aPath in subPaths) {
BOOL isDirectory;
[fileManager fileExistsAtPath:aPath isDirectory:&isDirectory];
if (isDirectory) {
// Change the permissions on the directory here
NSError *error = nil;
[fileManager setAttributes:attributes ofItemAtPath:aPath error:&error];
if (error) {
// Handle the error
}
}
}
This is untested, but should give you a starting point.
NSString *path = #"/User/user/aPath";
NSFileManager *manager = [[[NSFileManager alloc] init] autorelease];
if ([manager fileExistsAtPath: path]) {
NSDictionary *attrib = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:0], NSFileGroupOwnerAccountID,
[NSNumber numberWithInt:0], NSFileOwnerAccountID,
#"root", NSFileGroupOwnerAccountName,
#"root", NSFileOwnerAccountName, nil ];
NSError *error = nil;
[manager setAttributes:attrib ofItemAtPath:path error:&error];
NSDirectoryEnumerator *dirEnum = [manager enumeratorAtPath: path];
NSString *file;
while (file = [dirEnum nextObject]) {
[manager setAttributes:attrib ofItemAtPath:[path stringByAppendingPathComponent:file] error:&error];
}
}
How would I rename a file, keeping the file in the same directory?
I have a string containing a full path to a file, and a string containing a the new filename (and no path), for example:
NSString *old_filepath = #"/Volumes/blah/myfilewithrubbishname.avi";
NSString *new_filename = #"My Correctly Named File.avi";
I know about NSFileManager's movePath:toPath:handler: method, but I cannot workout how to construct the new file's path..
Basically I'm looking for the equivalent to the following Python code:
>>> import os
>>> old_filepath = "/Volumes/blah/myfilewithrubbishname.avi"
>>> new_filename = "My Correctly Named File.avi"
>>> dirname = os.path.split(old_filepath)[0]
>>> new_filepath = os.path.join(dirname, new_filename)
>>> print new_filepath
/Volumes/blah/My Correctly Named File.avi
>>> os.rename(old_filepath, new_filepath)
NSFileManager and NSWorkspace both have file manipulation methods, but NSFileManager's - (BOOL)movePath:(NSString *)source toPath:(NSString *)destination handler:(id)handler is probably your best bet. Use NSString's path manipulation methods to get the file and folder names right. For example,
NSString *newPath = [[oldPath stringByDeletingLastPathComponent] stringByAppendingPathComponent:newFilename];
[[NSFileManager defaultManager] movePath:oldPath toPath:newPath handler:nil];
Both classes are explained pretty well in the docs, but leave a comment if there's anything you don't understand.
It's worth noting that moving a file to itself will fail. I had a method that replaced spaces with underscores and made the file name lowercase and renamed the file to the new name. Files with only one word in the name would fail the rename as the new name would be identical on a case-insensitive file system.
The way I resolved this was to do a two step rename, first renaming the file to a temporary name and then renaming it to the intended name.
Some pseudocode explaining this:
NSString *source = #"/FILE.txt";
NSString *newName = [[source lastPathComponent] lowercaseString];
NSString *target = [[oldPath stringByDeletingLastPathComponent] stringByAppendingPathComponent:newName];
[[NSFileManager defaultManager] movePath:source toPath:target error:nil]; // <-- FAILS
The solution:
NSString *source = #"/FILE.txt";
NSString *newName = [[source lastPathComponent] lowercaseString];
NSString *temp = [[oldPath stringByDeletingLastPathComponent] stringByAppendingPathComponent:[NSString stringWithFormat:#"%#-temp", newName]];
NSString *target = [[oldPath stringByDeletingLastPathComponent] stringByAppendingPathComponent:newName];
[[NSFileManager defaultManager] movePath:source toPath:temp error:nil];
[[NSFileManager defaultManager] movePath:temp toPath:target error:nil];
I just wanted to make this easier to understand for a newbie. Here's all the code:
NSString *oldPath = #"/Users/brock/Desktop/OriginalFile.png";
NSString *newFilename = #"NewFileName.png";
NSString *newPath = [[oldPath stringByDeletingLastPathComponent] stringByAppendingPathComponent:newFilename];
[[NSFileManager defaultManager] movePath:oldPath toPath:newPath handler:nil];
NSLog( #"File renamed to %#", newFilename );
here's a more recent example for iOS, the NSFileManager method is a little different:
NSString *newFilename = [NSString stringWithFormat:#"%#.m4a", newRecording.title];
NSString *newPath = [[newRecording.localPath stringByDeletingLastPathComponent] stringByAppendingPathComponent:newFilename];
[[NSFileManager defaultManager] moveItemAtPath:newRecording.localPath toPath:newPath error:nil];
For the icing on top, a category on NSFileManager:
#implementation NSFileManager (FileManipulations)
- (void)changeFileNamesInDirectory:(NSString *)directory changeBlock:(NSString * (^) (NSString *fileName))block
{
NSString *inputDirectory = directory;
NSFileManager *fileManager = [NSFileManager new];
NSArray *fileNames = [fileManager contentsOfDirectoryAtPath:inputDirectory error:nil];
for (NSString *fileName in fileNames) {
NSString *newFileName = block(fileName);
NSString *oldPath = [NSString stringWithFormat:#"%#/%#", inputDirectory, oldFileName];
// move to temp path so case changes can happen
NSString *tempPath = [NSString stringWithFormat:#"%#-tempName", oldPath];
NSString *newPath = [[oldPath stringByDeletingLastPathComponent] stringByAppendingPathComponent:newFileName];
NSError *error = nil;
[fileManager moveItemAtPath:oldPath toPath:tempPath error:&error];
if (error) {
NSLog(#"%#", [error localizedDescription]);
return;
}
[fileManager moveItemAtPath:tempPath toPath:newPath error:&error];
if (error) {
NSLog(#"%#", [error localizedDescription]);
}
}
}
#end