Reading text file with NSString:stringWithContentsOfFile?
NSString *txtFilePath = [[NSBundle mainBundle] pathForResource:#"\help" ofType:#"txt"];
NSString *txtFileContents = [NSString stringWithContentsOfFile:txtFilePath encoding:NSUTF8StringEncoding error:NULL];
NSLog(#"File: %#",txtFileContents);
I get "null" as the result. How do I know what path to specify?
thanks
(I placed the file just under "Groups and Files" ... so not sure if I need to specify a path or just the file name. Maybe there is something else wrong ???
I think the backslash in your path is confusing things. Try this:
NSString *txtFilePath = [[NSBundle mainBundle] pathForResource:#"/help" ofType:#"txt"];
Also, as noted in the comments, you need to use the Build Phase of your project to copy the "help.txt" file.
Try this. What you want is the path to help.txt but you have to split it up into its name and extension for the method to work.
NSString *txtFilePath = [[NSBundle mainBundle] pathForResource: #"help" ofType: #"txt"];
It also wouldn't hurt to specify NULL instead of nil for the error argument. This is because nil represents objects whereas NULL represents pointers.
Here's a common file that I include in a ton of my projects (.h first, followed by .m):
I name this one FileHelpers.h:
#import <UIKit/UIKit.h>
NSString *pathInDocumentDirectory(NSString *fileName);
I name this one (of course) FileHelpers.m:
#include "FileHelpers.h"
NSString *pathInDocumentDirectory(NSString *fileName)
{
// Get list of document directories in sandbox
NSArray *documentDirectories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
// Get one and only one document directory from that list
NSString *documentDirectory = [documentDirectories objectAtIndex:0];
// Append passed in file name to that directory, return it
return [documentDirectory stringByAppendingPathComponent:fileName];
} // pathInDocumentDirectory
As an aside, I have to admit that I didn't come up with this solution myself, but it's been so long that I've used it that I can't remember now where I got it. If anyone knows, please feel free to attribute the appropriate credit!
Related
Can anyone help me to find what's wrong with my code while reading file from desktop
NSString *filename=#"~/Users/user12345/Desktop/Sample/Data.txt";
NSString *fileString=[NSString stringWithContentsOfFile:filename encoding:NSUTF8StringEncoding error:nil];
NSArray *namesArray=[fileString componentsSeparatedByString:#"\n"];
for(NSString *names in namesArray)
{
NSLog(#"names:%#",names);
}
If you want to use the tilde – which represents /User/<currentUser>/ – you have to ...expandingTildeInPath and remove /Users/user12345
NSString *filename = [#"~/Desktop/Sample/Data.txt" stringByExpandingTildeInPath];
that makes the path independent of the current user name, otherwise remove the tilde:
NSString *filename = #"/Users/user12345/Desktop/Sample/Data.txt";
Caveat: If your app is sandboxed the path does not point to the visible desktop.
NSString *filename=#"~/Users/user12345/Desktop/Sample/Data.txt";
The ~ used in a path is a convention which means your home directory, but it doesn't work in all contexts (e.g. when used in -stringWithContentsOfFile:`) and you've supplied an absolute path anyway. Remove it from the front of your path
NSString *filename=#"/Users/user12345/Desktop/Sample/Data.txt";
and it should work as long as the file does actually exist at that path.
Basically, I'm writing a video file to the Application Support directory and then saving it's path:
NSString *guid = [[NSUUID new] UUIDString];
NSString *outputFile = [NSString stringWithFormat:#"video_%#.mp4", guid];
NSString *outputDirectory = [NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *tempPath = [outputDirectory stringByAppendingPathComponent:outputFile];
NSURL *fileURL = [NSURL fileURLWithPath:tempPath]
// code to write a video to fileURL
I save the string path itself by calling [fileURL path];
Now later when I try to create an AVAssetItem from it, I can't actually get it to play.
EDIT:
Ok, so it seems the issue is the space in Application Support. I tried saving the file to just the Library directory and it worked fine.
So the question becomes, how can I play a video I save in the Application Support directory. I wasn't able to create a valid NSURL without escaping the space (when I tried it would return a nil NSURL) but it seems that the space/escaping doesn't allow it to play correctly.
Assume the NSURL to NSString conversion is required (unless it really should be avoided).
Also, side note, but if anyone could give some insight as to why this question was down voted so I can improve the quality of my questions, that would be appreciated. I don't understand?
While I am not informed enough to opine about whether this would change if I had used matt's recommended methods: URLForDirectory:inDomain:appropriateForURL:create:error: and URLByAppendingPathComponent: the actual issue here isn't converting an NSURL to NSString
It's that I'm saving the full URL ([fileURL path]). This is because the [NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES) objectAtIndex:0]; dynamically changes and the full path won't always point me to the appropriate file.
Instead I need to save just the name of my file (in my case I needed to persist outputFile) and then later dynamically build the the full path when I need it.
The same exact process:
NSString *outputDirectory = [NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *tempPath = [outputDirectory stringByAppendingPathComponent:outputFile];
NSURL *fileURL = [NSURL fileURLWithPath:tempPath];
worked just fine.
TLDR: Saving a full path doesn't work
Im trying to find a file with NSFileManager. The file exists but my path is never correct no matter how its phrased. The code I'm using is below. Why is NSFileManager not finding the file?
NSString *myFile = #"file1658.pdf";
NSFileManager *fileManager = [NSFileManager defaultManager];
if ([fileManager fileExistsAtPath:myFile]) {
NSLog(#"good");
}
MyFile is not a full path (e.g., "/Users/Joe/Documents/file1658.pdf"), so NSFileManager is looking for it in the current working directory. You can see what that is with -[NSFileManager currentDirectoryPath].
You need to either include the full path to the file as part of myFile, or set the proper working directory with -[NSFileManager changeCurrentDirectoryPath:].
// If myFile is in "/Users/joe/Documents"...
[fileManager changeCurrentDirectoryPath:#"/Users/joe/Documents"];
if ([fileManager fileExistsAtPath:myFile]) {
NSLog(#"good");
}
Apple tries hard to get you to put your files in sensible places. The file my exist, but you will have to either give the full path, e.g. /Users/user2759189/file1658.pdf or specify what folder it is in by other means.
App bundle
If the file is in your app bundle (for example, you have added it using "Add files to [project]" in XCode) you can get its path by something like:
NSString *myFile = [[NSBundle mainBundle] pathForResource:#"file1658" ofType:#"pdf"];
Search paths
You can look for user documents in a civilised manner by using the foundation function NSSearchPathForDirectoriesInDomains and some built in constants. If the file is in the user's Documents folder, for example, you can use something like:
NSString *documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *myFile = [documentsPath stringByAppendingPathComponent:#"file1658.pdf"];
I've looked at quite a few of the related questions and cannot find a similar problem or a solution so my apologies if there is a duplicate out there somewhere.
Anyway, I'm trying to generate a file's NSURL to use with an NSXMLDocument. I have the following components:
const NSString * PROJECT_DIR = #"~/SP\\ BB/";
const NSString * STRINGS_FILE = #"Localizable.strings";
and construct the URL like so:
NSURL * stringsURL = [NSURL fileURLWithPath:[[NSString stringWithFormat:#"%#%#",PROJECT_DIR,STRINGS_FILE] stringByExpandingTildeInPath]];
however, the resulting path in the NSURL is:
file://localhost/Users/timothyborrowdale/SP2B/Localizable.strings
I have tried changing the PROJECT_DIR to
#"~/SP BB/"
#"~/SP\\\\ BB/" (changes to SP엀2B)
#"~/SP%20BB/"
#"~/SP\%20BB/"
with the same problem. I also tried typing out the file url completely and using [NSURL URLWithString:]
I have also tried using stringByAddingPercentEscapesUsingEncoding with both NSUTF8Encoding and NSASCCIEncoding and these have the same issue.
The NSString displays properly before being passed to NSURL or stringByAddingPercentEscapesUsingEncoding but has the problem once outputted from either.
Try this:
NSString *fnam = [#"Localizable" stringByAppendingPathExtension:#"strings"];
NSArray *parts = [NSArray arrayWithPathComponents:#"~", #"SP BB", fnam, (void *)nil];
NSString *path = [[NSString pathWithComponents:parts] stringByStandardizingPath];
NSURL *furl = [NSURL fileURLWithPath:path];
Foundation has a host of platform-independent, path-related methods. Prefer those over hard-coding path extension separators (often ".") and path component separators (often "/" or "\").
Try abandoning stringWithFormat: (never the right answer for stapling paths together) and stringByExpandingTildeInPath and using NSHomeDirectory() and stringByAppendingPathComponent: instead.
#"~/SP\\ BB/" (changes to SP엀2B)
How did you arrive at that conclusion?
I'm using a text file to save the changes made by a user on a list (the reason that I'm doing this is so that I can upload the text file to a PC later on, and from there insert it into an Excel spreadsheet). I have 3 data structures: A NSMutableArray of keys, and a NSMutableDictionary who's key values are MSMutableArrays of NSStrings.
I iterate through these data structures and compile a file string that looks much like this:
(Key);(value)\t(value)\t(value):\n(Key);(value).. .so on.
SO, onto the actual question: When I attempt to save it, it fails. I'm 99% sure this is because of the file path that I'm using, but I wanted backup to check this out. Code follows:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
NSString *filePath = [paths objectAtIndex:0];
NSString *fileString = [NSString stringWithString:[self toFileString]];
if(![fileString writeToFile:filePath atomically:YES encoding:NSUTF8StringEncoding error:NULL]){
NSLog(#"File save failed");
} else {
// do stuff
}
(Code above is re-copied, since the actual code is on a different computer. It compiles, so ignore spelling errors?)
I tried using NSError, but I got bogged down in documentation and figured I might as well ask SO while trying to figure out how to properly use NSError (might be a little bit of an idiot, sorry).
99% sure it's the NSArray *paths line that's tripping it up, but I don't know how else to get the documents directory.
Edit: Problem solved, and one final question: If I save it to the App's document directory, where can I go after I close the app to see if it saved properly? If it works like I think it does, isn't it sandboxed in with the app's installation on the simulator? (i.e. no way of checking it)
NSLog() that filePath string. I think you're trying to write to the directory itself, not to a file.
Try this instead:
filePath = [[paths objectAtIndex:0]stringByAppendingPathComponent:#"myfile.txt"];
What is the file name you want to save? The method
NSArray *paths = NSSearchPathForDirectoriesInDomains(...);
NSString *filePath = [paths objectAtIndex:0];
...
if(![fileString writeToFile:filePath ...
means you are saving the string into a file path which has the same name as a folder. This will of course fail. Please give it a name, e.g.
NSString* fileName = [filePath stringByAppendingPathComponent:#"file.txt"];
if(![fileString writeToFile:fileName ...
and try again.
BTW, to use NSError:
NSError* theError = nil;
if(![fileString writeToFile:fileName ... error:&theError]) {
// ^^^^^^^^^
NSLog(#"Failed with reason %#", theError);
// theError is autoreleased.
}