How to split filename from file extension in Swift?
IosStringSwiftIos Problem Overview
Given the name of a file in the bundle, I want load the file into my Swift app. So I need to use this method:
let soundURL = NSBundle.mainBundle().URLForResource(fname, withExtension: ext)
For whatever reason, the method needs the filename separated from the file extension. Fine, it's easy enough to separate the two in most languages. But so far I'm not finding it to be so in Swift.
So here is what I have:
var rt: String.Index = fileName.rangeOfString(".", options:NSStringCompareOptions.BackwardsSearch)
var fname: String = fileName .substringToIndex(rt)
var ext = fileName.substringFromIndex(rt)
If I don't include the typing on the first line, I get errors on the two subsequent lines. With it, I'm getting an error on the first line:
Cannot convert the expression's type '(UnicodeScalarLiteralConvertible, options: NSStringCompareOptions)' to type 'UnicodeScalarLiteralConvertible'
How can I split the filename from the extension? Is there some elegant way to do this?
I was all excited about Swift because it seemed like a much more elegant language than Objective C. But now I'm finding that it has its own cumbersomeness.
Second attempt: I decided to make my own string-search method:
func rfind(haystack: String, needle: Character) -> Int {
var a = Array(haystack)
for var i = a.count - 1; i >= 0; i-- {
println(a[i])
if a[i] == needle {
println(i)
return i;
}
}
return -1
}
But now I get an error on the line var rt: String.Index = rfind(fileName, needle: ".")
:
'Int' is not convertible to 'String.Index'
Without the cast, I get an error on the two subsequent lines.
Can anyone help me to split this filename and extension?
Ios Solutions
Solution 1 - Ios
Swift 5.0 update:
As pointed out in the comment, you can use this.
let filename: NSString = "bottom_bar.png"
let pathExtention = filename.pathExtension
let pathPrefix = filename.deletingPathExtension
Solution 2 - Ios
This is with Swift 2, Xcode 7: If you have the filename with the extension already on it, then you can pass the full filename in as the first parameter and a blank string as the second parameter:
let soundURL = NSBundle.mainBundle()
.URLForResource("soundfile.ext", withExtension: "")
Alternatively nil as the extension parameter also works.
If you have a URL, and you want to get the name of the file itself for some reason, then you can do this:
soundURL.URLByDeletingPathExtension?.lastPathComponent
Swift 4
let soundURL = NSBundle.mainBundle().URLForResource("soundfile.ext", withExtension: "")
soundURL.deletingPathExtension().lastPathComponent
Solution 3 - Ios
Works in Swift 5. Adding these behaviors to String
class:
extension String {
func fileName() -> String {
return URL(fileURLWithPath: self).deletingPathExtension().lastPathComponent
}
func fileExtension() -> String {
return URL(fileURLWithPath: self).pathExtension
}
}
Example:
let file = "image.png"
let fileNameWithoutExtension = file.fileName()
let fileExtension = file.fileExtension()
Solution 4 - Ios
Solution Swift 4
This solution will work for all instances and does not depend on manually parsing the string.
let path = "/Some/Random/Path/To/This.Strange.File.txt"
let fileName = URL(fileURLWithPath: path).deletingPathExtension().lastPathComponent
Swift.print(fileName)
The resulting output will be
This.Strange.File
Solution 5 - Ios
In Swift 2.1 String.pathExtension is not available anymore. Instead you need to determine it through NSURL conversion:
NSURL(fileURLWithPath: filePath).pathExtension
Solution 6 - Ios
In Swift you can change to NSString
to get extension faster:
extension String {
func getPathExtension() -> String {
return (self as NSString).pathExtension
}
}
Solution 7 - Ios
Latest Swift 4.2 works like this:
extension String {
func fileName() -> String {
return URL(fileURLWithPath: self).deletingPathExtension().lastPathComponent
}
func fileExtension() -> String {
return URL(fileURLWithPath: self).pathExtension
}
}
Solution 8 - Ios
In Swift 2.1, it seems that the current way to do this is:
let filename = fileURL.URLByDeletingPathExtension?.lastPathComponent
let extension = fileURL.pathExtension
Solution 9 - Ios
SWIFT 3.x Shortest Native Solution
let fileName:NSString = "the_file_name.mp3"
let onlyName = fileName.deletingPathExtension
let onlyExt = fileName.pathExtension
No extension or any extra stuff (I've tested. based on @gabbler solution for Swift 2)
Solution 10 - Ios
Strings in Swift can definitely by tricky. If you want a pure Swift method, here's how I would do it:
- Use
find
to find the last occurrence of a"."
in thereverse
of the string - Use
advance
to get the correct index of the"."
in the original string - Use
String
'ssubscript
function that takes anIntervalType
to get the strings - Package this all up in a function that returns an optional tuple of the name and extension
Something like this:
func splitFilename(str: String) -> (name: String, ext: String)? {
if let rDotIdx = find(reverse(str), ".") {
let dotIdx = advance(str.endIndex, -rDotIdx)
let fname = str[str.startIndex..<advance(dotIdx, -1)]
let ext = str[dotIdx..<str.endIndex]
return (fname, ext)
}
return nil
}
Which would be used like:
let str = "/Users/me/Documents/Something.something/text.txt"
if let split = splitFilename(str) {
println(split.name)
println(split.ext)
}
Which outputs:
/Users/me/Documents/Something.something/text
txt
Or, just use the already available NSString
methods like pathExtension
and stringByDeletingPathExtension
.
Solution 11 - Ios
Swift 5
URL(string: filePath)?.pathExtension
Solution 12 - Ios
Swift 5 with code sugar
extension String {
var fileName: String {
URL(fileURLWithPath: self).deletingPathExtension().lastPathComponent
}
var fileExtension: String{
URL(fileURLWithPath: self).pathExtension
}
}
Solution 13 - Ios
Swift 5
URL.deletingPathExtension().lastPathComponent
Solution 14 - Ios
Try this for a simple Swift 4 solution
extension String {
func stripExtension(_ extensionSeperator: Character = ".") -> String {
let selfReversed = self.reversed()
guard let extensionPosition = selfReversed.index(of: extensionSeperator) else { return self }
return String(self[..<self.index(before: (extensionPosition.base.samePosition(in: self)!))])
}
}
print("hello.there.world".stripExtension())
// prints "hello.there"
Solution 15 - Ios
Swift 3.0
let sourcePath = NSURL(string: fnName)?.pathExtension
let pathPrefix = fnName.replacingOccurrences(of: "." + sourcePath!, with: "")
Solution 16 - Ios
Swift 3.x extended solution:
extension String {
func lastPathComponent(withExtension: Bool = true) -> String {
let lpc = self.nsString.lastPathComponent
return withExtension ? lpc : lpc.nsString.deletingPathExtension
}
var nsString: NSString {
return NSString(string: self)
}
}
let path = "/very/long/path/to/filename_v123.456.plist"
let filename = path.lastPathComponent(withExtension: false)
filename constant now contains "filename_v123.456"
Solution 17 - Ios
A better way (or at least an alternative in Swift 2.0) is to use the String pathComponents property. This splits the pathname into an array of strings. e.g
if let pathComponents = filePath.pathComponents {
if let last = pathComponents.last {
print(" The last component is \(last)") // This would be the extension
// Getting the last but one component is a bit harder
// Note the edge case of a string with no delimiters!
}
}
// Otherwise you're out of luck, this wasn't a path name!
Solution 18 - Ios
They got rid of pathExtension for whatever reason.
let str = "Hello/this/is/a/filepath/file.ext"
let l = str.componentsSeparatedByString("/")
let file = l.last?.componentsSeparatedByString(".")[0]
let ext = l.last?.componentsSeparatedByString(".")[1]
Solution 19 - Ios
A cleaned up answer for Swift 4 with an extension off of PHAsset
:
import Photos
extension PHAsset {
var originalFilename: String? {
if #available(iOS 9.0, *),
let resource = PHAssetResource.assetResources(for: self).first {
return resource.originalFilename
}
return value(forKey: "filename") as? String
}
}
As noted in XCode, the originalFilename is the name of the asset at the time it was created or imported.
Solution 20 - Ios
Maybe I'm getting too late for this but a solution that worked for me and consider quite simple is using the #file
compiler directive. Here is an example where I have a class FixtureManager
, defined in FixtureManager.swift
inside the /Tests/MyProjectTests/Fixturesdirectory. This works both in Xcode and with
swift test`
import Foundation
final class FixtureManager {
static let fixturesDirectory = URL(fileURLWithPath: #file).deletingLastPathComponent()
func loadFixture(in fixturePath: String) throws -> Data {
return try Data(contentsOf: fixtureUrl(for: fixturePath))
}
func fixtureUrl(for fixturePath: String) -> URL {
return FixtureManager.fixturesDirectory.appendingPathComponent(fixturePath)
}
func save<T: Encodable>(object: T, in fixturePath: String) throws {
let data = try JSONEncoder().encode(object)
try data.write(to: fixtureUrl(for: fixturePath))
}
func loadFixture<T: Decodable>(in fixturePath: String, as decodableType: T.Type) throws -> T {
let data = try loadFixture(in: fixturePath)
return try JSONDecoder().decode(decodableType, from: data)
}
}
Solution 21 - Ios
Creates unique "file name" form url including two previous folders
func createFileNameFromURL (colorUrl: URL) -> String {
var arrayFolders = colorUrl.pathComponents
// -3 because last element from url is "file name" and 2 previous are folders on server
let indx = arrayFolders.count - 3
var fileName = ""
switch indx{
case 0...:
fileName = arrayFolders[indx] + arrayFolders[indx+1] + arrayFolders[indx+2]
case -1:
fileName = arrayFolders[indx+1] + arrayFolders[indx+2]
case -2:
fileName = arrayFolders[indx+2]
default:
break
}
return fileName
}