I am trying to import the content of a .txt file to a string in my Xcode 9 project using Swift 4. When I use the full path name it imports successfully, current code:
let filePath = URL(fileURLWithPath: "/Users/main/Documents/ClaasPDI/PDIapp/PDIapp/holdMachines.txt")
do
{
machineString = try String(contentsOf: filePath)
}
catch
{
print("MACHINE INFORMATION DID NOT IMPORT")
}
I want to be able to import the data from the local path so it can be run on other computers besides mine. My swift files and holdMachines.txt are in the same folder PDIapp but when I change the code to:
let filePath = URL(fileURLWithPath: "holdMachines.txt")
it now crashes my app and says it could not access the file.
I also tried it with a / infront of the file name (below) but that also failed.
let filePath = URL(fileURLWithPath: "/holdMachines.txt")
How can I change my code to access the file through a local file path?
Put the text file in your Xcode project and use the following code to read it into a string:
let txtFile = Bundle.main.path(forResource: "holdMachines", ofType: "txt")
do {
let contents = try? String(contentsOfFile: txtFile!, encoding: .utf8)
} catch let err {
print(err.localizedDescription)
}
Related
I'm just starting learning Swift and to teach myself I'm making a simple command line app. It will eventually connect to an online data source but initially I want to load data from a file. I've seen various guides on reading the contents of a file in Swift but none of them seem to work for me. Here is my app so far:
import Foundation
// Set the file path
let path = "/Users/username/workspace/Swift/sis/sis/data.json"
do {
// Get the contents
let contents = try String(contentsOfFile: path, encoding: .utf8)
print(contents)
}
catch let error as NSError {
print("Ooops! Something went wrong: \(error)")
}
Running it outputs:
Ooops! Something went wrong: Error Domain=NSCocoaErrorDomain Code=260 "The file “data.json” couldn’t be opened because there is no such file." UserInfo={NSFilePath=/Users/username/workspace/Swift/sis/sis/data.json, NSUnderlyingError=0x100e19a50 {Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"}}
However on the terminal:
$ ls -l /Users/username/workspace/Swift/sis/sis/data.json
-rwxrwxrwx# 1 username staff 165563 16 Jan 17:14 /Users/username/workspace/Swift/sis/sis/data.json
(yeah I relaxed the permissions somewhat just in case that was the problem)
The only slightly anomalous thing I noticed (aside from the inaccurate assertion that the file doesn't exist) was that when I copy and past the path from the XCode output into iTerm2 it puts spaces between each path component:
(pasted as an image as copying it and pasting it back into this form seems to hide the spaces - this is probably irrelevant anyway)
Any help figuring this out would be really appreciated!
I copied your code, downloaded a sample json file to my desktop, and renamed it to example_ 1.json (I included a space inside the file name).
import Foundation
// Set the file path
let path = "/Users/username/Desktop/example_ 1.json"
do {
// Get the contents
let contents = try String(contentsOfFile: path, encoding: .utf8)
print(contents)
}
catch let error as NSError {
print("Ooops! Something went wrong: \(error)")
}
It successfully printed the file. It also worked when I defined contents as a NSString.
let contents = try NSString(contentsOfFile: path,
encoding: String.Encoding.ascii.rawValue)
I am using Swift 4.2.1
you can not read if your command line app is sandboxed. what you can do is to add this file in your project and set path of file by looking the full path of file in identity inspector.
let path = "/Users/snx/EmailReplacer/EmailReplacer/shared_domains_staging.json"
do {
let data = try Data(contentsOf: URL(fileURLWithPath: path), options: .mappedIfSafe)
let jsonResult = try JSONSerialization.jsonObject(with: data, options: .mutableLeaves)
if let jsonResult = jsonResult as? Dictionary<String, AnyObject> {
print(jsonResult)
}
} catch {
print(error)
}
I’m trying to get String from txt file inside the zip file using native libcompression library. Actually I use the code from
https://github.com/mw99/DataCompression/blob/master/Sources/DataCompression.swift.
At first, I was doing:
let zip = try? Data(contentsOf: "/.../test.zip")
let tmp: Data? = zip?.unzip()
let txt: String? = String(data: tmp!, encoding: .utf8)
But how do I get the contents of zip file and how do I get data from certain txt file?
ZIP Foundation supports accessing individual entries in ZIP archives.
You have to initialize an archive by passing a file URL to the Archive initializer.
Afterwards you can access a specific entry via subscripting:
let fileManager = FileManager()
let currentWorkingPath = fileManager.currentDirectoryPath
var archiveURL = URL(fileURLWithPath: currentWorkingPath)
archiveURL.appendPathComponent("test.zip")
guard let archive = Archive(url: archiveURL, accessMode: .read) else {
return
}
guard let entry = archive["file.txt"] else {
return
}
var destinationURL = URL(fileURLWithPath: currentWorkingPath)
destinationURL.appendPathComponent("out.txt")
do {
try archive.extract(entry, to: destinationURL)
} catch {
print("Extracting entry from archive failed with error:\(error)")
}
You can also directly access the contents of entry by using the closure based API. This allows you to process the entry without writing it to the file system first:
try archive.extract(entry, consumer: { (data) in
print(data.count)
})
I have a data set of audio files in my Assets.xcassets:
I'm trying to get the path of one of those audio files like this:
let path: String = Bundle.main.path(forResource: "acoustic_grand_piano/A4", ofType: "f32")!
But I get a EXC_BAD_INSTRUCTION. I tried to look on the internet but I don't find anything on Data Sets.
How can I get the content of one of these files?
Thanks!
Try this:
Manually put your files into a folder, named anything you want.
Append ".bundle" to the folder to create a bundle. You'll get a warning, accept it. Congrats, you've just created your first bundle! :-)
Manually drag that folder into your app.
Get at your files by using the following code....
public func returnFile(_ named:String) -> String {
let path: String = Bundle.main.path(forResource: "myAudioFiles", ofType: "bundle")! + "/" + name + ".f32"
do {
return try String(contentsOfFile: path)
}
catch let error as NSError {
return error.description
}
}
Now, my files are text files of CIKernel code. Since your's are audio files you may need to change the String return to something else.
EDIT:
In my case I'm using a framework, as I wish to share these files/images with extensions and other apps. If you are working in such a set up, here's the unaltered code:
public func returnFile(_ resource:String, _ fileName:String, _ fileType:String) -> String {
let identifier = "com.companyname.appname" // replace with framework bundle identifier
let fileBundle = Bundle.init(identifier: identifier)
let filePath = (fileBundle?.path(forResource: resource, ofType: "bundle"))! + "/" + fileName + "." + fileType
do {
return try String(contentsOfFile: filePath)
}
catch let error as NSError {
return error.description
}
}
I need to preload SQLite files from my bundle's resources into the application support directory. I want to make sure the correct files are there vs. the empty files that Core Data puts there by default. To do this, I'm using FileManager.default.contentsEqual; however, this always returns false.
I tried testing with a playground, but the copy there is creating alias files, still resulting in a false comparison.
In the app, the files do copy over with the same name and size. The dates are different: the copies have the current date/time rather than the original's timestamps. Using contentsEqual, though, I wouldn't think that matters.
Update: diff at the command line shows the files are the same...
What am I missing?
Here's the code from the playground, which is virtually the same as my app code:
// get the URL for the application support directory
let appSupportDir: URL = try!
FileManager.default.url(for: FileManager.SearchPathDirectory.applicationSupportDirectory,
in: FileManager.SearchPathDomainMask.userDomainMask,
appropriateFor: nil, create: true)
// get the source URLs for the preload files
let sqliteFileBundleURL: URL = Bundle.main.url(forResource: "My_DB", withExtension: "sqlite")!
let sqliteShmFileBundleURL: URL = Bundle.main.url(forResource: "My_DB", withExtension: "sqlite-shm")!
let sqliteWalFileBundleURL: URL = Bundle.main.url(forResource: "My_DB", withExtension: "sqlite-wal")!
// create target URLs for copy to application support directory
let sqliteFileAppSptURL: URL = appSupportDir.appendingPathComponent("My_DB.sqlite")
let sqliteShmFileAppSptURL: URL = appSupportDir.appendingPathComponent("My_DB.sqlite-shm")
let sqliteWalFileAppSptURL: URL = appSupportDir.appendingPathComponent("My_DB.sqlite-wal")
// remove the files if they already exist at the target (for test - app doesn't do this)
do {
let filesFound: [URL] = try FileManager.default.contentsOfDirectory(at: appSupportDir,
includingPropertiesForKeys: nil,
options: .skipsHiddenFiles)
if !filesFound.isEmpty {
for fileURL in filesFound {
try FileManager.default.removeItem(at: fileURL)
}
print("Removed \(filesFound.count) files without error.")
}
}
catch {
print("Error:\n\(error)")
}
// copy the files to the application support directory
do {
try FileManager.default.copyItem(at: sqliteFileBundleURL, to: sqliteFileAppSptURL)
try FileManager.default.copyItem(at: sqliteShmFileBundleURL, to: sqliteShmFileAppSptURL)
try FileManager.default.copyItem(at: sqliteWalFileBundleURL, to: sqliteWalFileAppSptURL)
}
catch {
print("Error: \(error)")
}
// compare the copied target files to their source using contentsEqual
let sqliteFileCopied: Bool =
FileManager.default.contentsEqual(atPath: sqliteFileBundleURL.absoluteString, andPath: sqliteFileAppSptURL.absoluteString)
let sqliteShmFileCopied: Bool =
FileManager.default.contentsEqual(atPath: sqliteShmFileBundleURL.absoluteString, andPath: sqliteShmFileAppSptURL.absoluteString)
let sqliteWalFileCopied: Bool =
FileManager.default.contentsEqual(atPath: sqliteWalFileBundleURL.absoluteString, andPath: sqliteWalFileAppSptURL.absoluteString)
Aha! When using FileManager, one should be using path rather than absoluteString to convert a URL to a String:
// compare the copied target files to their source using contentsEqual
let sqliteFileCopied: Bool =
FileManager.default.contentsEqual(atPath: sqliteFileBundleURL.path, andPath: sqliteFileAppSptURL.path)
let sqliteShmFileCopied: Bool =
FileManager.default.contentsEqual(atPath: sqliteShmFileBundleURL.path, andPath: sqliteShmFileAppSptURL.path)
let sqliteWalFileCopied: Bool =
FileManager.default.contentsEqual(atPath: sqliteWalFileBundleURL.path, andPath: sqliteWalFileAppSptURL.path)
The difference between the two is that path generates a file system-type path:
/var/folders/kb/y2d_vrl133d1b04_5kc3kw880000gn/T/com.apple.dt.Xcode.pg/resources/238FF955-236A-42FC-B6EA-9A74FC52F235/My_DB.sqlite
whereas absoluteString generates a browser-friendly path:
file:///var/folders/kb/y2d_vrl133d1b04_5kc3kw880000gn/T/com.apple.dt.Xcode.pg/resources/238FF955-236A-42FC-B6EA-9A74FC52F235/My_DB.sqlite
Note: path also works in the playground with the alias files.
I'm trying to learn the new Swift programming language. It looks great, but I'm having a difficult time doing something as simple as reading the content of a local .txt file.
I have tried the few examples I could find through Google, but they give compile errors, like this answer here: Read and write data from text file
If I tweak the code a bit, it works, but can only read from a special location within the project.
Why isn't it just as simple to read a .txt file with Swift as it is with for instance Ruby? And how would I go about reading the content of a file located at ~/file.txt?
Thnx
If you have a tilde in your path you can try this:
let location = "~/file.txt".stringByExpandingTildeInPath
let fileContent = NSString(contentsOfFile: location, encoding: NSUTF8StringEncoding, error: nil)
otherwise just use this:
let location = "/Users/you/Desktop/test.txt"
let fileContent = NSString(contentsOfFile: location, encoding: NSUTF8StringEncoding, error: nil)
This gives you a string representation of the file, which I assumed is what you want.
You can use NSData(contentsOfFile: location) to get a binary representation, but you would normally do that for, say, music files and not a text file.
Update: With Xcode 7 and Swift 2 this doesn't work anymore. You can now use
let location = NSString(string:"~/file.txt").stringByExpandingTildeInPath
let fileContent = try? NSString(contentsOfFile: location, encoding: NSUTF8StringEncoding)
let file = "/Users/user/Documents/text.txt"
let path=URL(fileURLWithPath: file)
let text=try? String(contentsOf: path)
This would work:
let path = "~/file.txt"
let expandedPath = path.stringByExpandingTildeInPath
let data: NSData? = NSData(contentsOfFile: expandedPath)
if let fileData = data {
let content = NSString(data: fileData, encoding:NSUTF8StringEncoding) as String
}
Note that data may be nil, so you should check for that.
EDIT:
Don't forget conditional unwrapping - looks much nicer ;)
Relative path tip:
Instead of doing this:
NSString("~/file.txt").stringByExpandingTildeInPath
You can do this:
"\(NSHomeDirectory())/file.txt"
You may find this tool useful to not only read from file in Swift but also parse it simultaneously: https://github.com/shoumikhin/StreamScanner
Just specify the file path and data delimiters like this (see readme for more options):
import StreamScanner
if let input = NSFileHandle(forReadingAtPath: "/file/path")
{
let scanner = StreamScanner(source: input, delimiters: NSCharacterSet(charactersInString: ":\n")) //separate data by colons and newlines
while let field: String = scanner.read()
{
//use field
}
}
Hope, this helps.
Using the answer by Atomix, this will work in Swift 4:
let location = NSString(string: "~/test.txt").expandingTildeInPath
let fileContent = try? NSString(contentsOfFile: location, encoding: String.Encoding.utf8.rawValue)
This worked for me in Swift 2.1, XCode7 to get the location and print the contents of CSV. ( you can create a simple CSV in Text Wrangler)
override func viewDidLoad() {
super.viewDidLoad()
let location = NSString(string:"/Users/*Myusername*/Documents/myCSVfile.csv")
let fileContent = try? NSString(contentsOfFile: location as String, encoding: NSUTF8StringEncoding)
print(fileContent)
}
Swift 4:
let filePath = "/Users/UserName/Desktop/FolderName/FileName.txt"
let fullPath = NSString(string: filePath).expandingTildeInPath
do
{
let fileContent = try NSString(contentsOfFile: fullPath, encoding: String.Encoding.utf8.rawValue)
print(fileContent)
}
catch
{
print(error)
}
filename doesn't need to have scheme like file://, and can be relative like ../docs/test.txt.
Remember to catch any error thrown, or rethrow.
let url = URL(fileURLWithPath: filename)
let contents = try String(contentsOf: url, encoding: .utf8)