CODEWITHSUNDEEP
cocoastringnsstringfilenames
cocoafan
cocoafan

Reputation: 4894

How to make an NSString path (file name) safe

I'm using very tricky fighting methods :) to make a string like Fi?le*/ Name safe for using as a file name like File_Name. I'm sure there is a cocoa way to convert it. And I'm sure the best place to ask is here :)

Thank you!

Upvotes: 44

Views: 17010

Answers (8)

NSGodMode
NSGodMode

Reputation: 627

I used jhones answer but improved for iOS. because ' causes paths to become invalid. and I removed . too just to avoid wired filetypes being generated.

Now if a file name contains "sam's" becomes it "sams", fixed the problem I was encountering

+ (NSString *)_sanitizeFileNameString:(NSString *)fileName {
    NSCharacterSet* illegalFileNameCharacters = [NSCharacterSet characterSetWithCharactersInString:@"/\\?%*|\"<'.>"];
    return [[fileName componentsSeparatedByCharactersInSet:illegalFileNameCharacters] componentsJoinedByString:@""];
}

Upvotes: 0

Charlton Provatas
Charlton Provatas

Reputation: 2274

Solution in Swift 4

extension String {
    var sanitizedFileName: String {
        return components(separatedBy: .init(charactersIn: "/\:\?%*|\"<>")).joined()
    }
}

Usage:

"https://myurl.com".sanitizedFileName // = httpsmyurl.com

Upvotes: 5

SeanR
SeanR

Reputation: 7979

I iterated on johnboiles's answer, converting to Swift, and writing it as an extension:

extension String {
    var stringForFilePath: String {
        // characterSet contains all illegal characters on OS X and Windows
        let characterSet = NSCharacterSet(charactersInString: "\"\\/?<>:*|")
        // replace "-" with character of choice
        return componentsSeparatedByCharactersInSet(characterSet).joinWithSeparator("-")
    }
}

Illegal character set referenced from here.

Upvotes: 4

Anton Tropashko
Anton Tropashko

Reputation: 5806

And of course there's got to be a swift2 guy with an arbitrary hate list (stolen from other answers). That guy is me:

func sanitizedString(string : String) -> String {
    // put anything you dislike in that set ;-)
    let invalidFsChars = NSCharacterSet(charactersInString: "/* <>?%|")
    let components = string.componentsSeparatedByCharactersInSet(invalidFsChars)
    return components.joinWithSeparator("")
}

Upvotes: 2

tyljohnny
tyljohnny

Reputation: 41

NSURL *fileURL = [NSURL fileURLWithPath:yourFilePath isDirectory:NO];

if (fileURL) {

    NSError *error;

    fileURL = [NSURL URLByResolvingAliasFileAtURL:fileURL options:(NSURLBookmarkResolutionWithoutUI | NSURLBookmarkResolutionWithoutMounting) error:&error];

}

Before Transfer:

/Users/XXX/Desktop/~!@#$%^&*()_+`-={}|"<>?[]\;',.: {}<>:^ .png

After Transfer:

file:///Users/johnny/Desktop/~!@%23$%25%5E&*()_+%60-=%7B%7D%7C%22%3C%3E%3F%5B%5D%5C%3B',.:%20%20%7B%7D%3C%3E%5C:%5E%20.png

Upvotes: 4

johnboiles
johnboiles

Reputation: 3524

This will remove all invalid characters anywhere in the filename based on Ismail's invalid character set (I have not verified how complete his set is).

- (NSString *)_sanitizeFileNameString:(NSString *)fileName {
    NSCharacterSet* illegalFileNameCharacters = [NSCharacterSet characterSetWithCharactersInString:@"/\\?%*|\"<>"];
    return [[fileName componentsSeparatedByCharactersInSet:illegalFileNameCharacters] componentsJoinedByString:@""];
}

Credit goes to Peter N Lewis for the idea to use componentsSeparatedByCharactersInSet:
NSString - Convert to pure alphabet only (i.e. remove accents+punctuation)

Upvotes: 68

Ismail Degani
Ismail Degani

Reputation: 887

According to wikipedia, the most common characters that should be excluded from filenames are:

/\?%*|"<>

http://en.wikipedia.org/wiki/Filename

Given that, and since the invertedSet operation in the alternate solution can be intensive, to me the below is a cleaner approach:

NSCharacterSet *invalidFsChars = [NSCharacterSet characterSetWithCharactersInString:@"/\\?%*|\"<>"];
NSString *scrubbed = [originalStr stringByTrimmingCharactersInSet:invalidFsChars];

This way you can still allow filenames that have dash, etc.

Upvotes: -3

Peter Hosey
Peter Hosey

Reputation: 96333

Unless you're explicitly running the shell or implicitly running the shell by using a function such as popen or system, there's no reason to escape anything but the pathname separator.

You may also want to enforce that the filename does not begin with a full stop (which would cause Finder to hide the file) and probably should also enforce that it is not empty and is fewer than NAME_MAX characters* long.

*syslimits.h says bytes, but if you go through File Manager, it's characters. I'm not sure which is right for Cocoa.

Upvotes: 18

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