Objective-c: Use of Nsfilemanager

In the Foundation framework in Objective-c, file operations are implemented by the Nsfilemanager class.

Here's an example of how to create a file, write to a file, and read the contents of a file:

require 'ripl'
require 'ripl / shell_commands'
require 'ripl / color_result'
require 'ripl / color_streams'
require 'ripl / commands'
require 'ripl / rocket'

#Set output color
Ripl.config [: color_streams_stdout] =: light_blue
Ripl.config [: color_streams_stderr] =: light_red

#Definition prompt symbol
Ripl.config [: prompt] = lambda {"[# {Ripl.shell.line.to_s}] cmd>"}

# Define plugins, load files, etc ...

class Dodolook
 def help
 puts "xiaomi noops blog"
 end
 def name
 "wilbur"
 end
end
dodo = Dodolook.new

verison = "1.0.3"
Ripl.start: binding => dodo.instance_eval {binding}
-(void) testFileCreate
{
    NSFileManager * fileManager = [NSFileManager defaultManager];
    NSString * filePath = [NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
    filePath = [filePath stringByAppendingPathComponent: @ "new.txt"];
    NSLog (@ "filePath =% @", filePath);
    // determine if the file exists
    if (! [fileManager fileExistsAtPath: filePath]) {
        // If the file does not exist, create a new file
        [fileManager createFileAtPath: filePath contents: nil attributes: nil];
    }
    // Write content to the file, implemented by file handle, NSFileHandle
    NSFileHandle * fileHandle = [NSFileHandle fileHandleForWritingAtPath: filePath];
    NSString * content = @ "hey, brother.This is a test.";
    NSData * contentData = [content dataUsingEncoding: NSUTF8StringEncoding];
    [fileHandle writeData: contentData];
    // close the file
    [fileHandle closeFile];
    
    // read the contents of the file
    fileHandle = [NSFileHandle fileHandleForReadingAtPath: filePath];
    NSData * readData = [fileHandle readDataToEndOfFile];
    // data to NSString
    NSString * readStr = [[NSString alloc] initWithData: readData encoding: NSUTF8StringEncoding];
    NSLog (@ "readStr =% @", readStr);
    [fileHandle closeFile];
    // Read the file directly as NSString
    NSString * contentStr = [NSString stringWithContentsOfFile: filePath encoding: NSUTF8StringEncoding error: nil];
    NSLog (@ "contentStr =% @", contentStr);
}...

Some general operations of files, such as copying files, deleting files, moving files, and so on:

-(void) testFileOperation
{
    // get the temporary directory
    NSString * tempPath = NSTemporaryDirectory ();
    NSLog (@ "tempPath =% @", tempPath);
    // last level directory
    NSLog (@ "last =% @", [tempPath lastPathComponent]);
    // Add a level directory at the end, the original directory is unchanged, and a new directory string is returned
    NSLog (@ "add last =% @", [tempPath stringByAppendingPathComponent: @ "add"]);
    // Delete the last directory, the original directory is unchanged, and return a new directory string
    NSLog (@ "del last =% @", [tempPath stringByDeletingLastPathComponent]);
    NSString * filePath = [tempPath stringByAppendingPathComponent: @ "test.txt"];
    NSLog (@ "filePath =% @", filePath);
    // extension, output as txt
    NSLog (@ "extension =% @", [filePath pathExtension]);
    NSFileManager * manager = [NSFileManager defaultManager];
    if (! [manager fileExistsAtPath: filePath]) {
        [manager createFileAtPath: filePath contents: nil attributes: nil];
    }
    
    NSString * newPath = [tempPath stringByAppendingPathComponent: @ "newtest.txt"];
    // copy the file
    [manager copyItemAtPath: filePath toPath: newPath error: nil];
    if ([manager fileExistsAtPath: newPath]) {
        NSLog (@ "copy success");
    }
    // Delete Files
    [manager removeItemAtPath: newPath error: nil];
    if (! [manager fileExistsAtPath: newPath]) {
        NSLog (@ "remove success");
    }
    
    // whether the file is readable
    if ([manager isReadableFileAtPath: filePath]) {
        NSLog (@ "readable");
    }
    // whether the file is writable
    if ([manager isWritableFileAtPath: filePath]) {
        NSLog (@ "writeable");
    }
} 

Objective-c: Use of Nsfilemanager