Author: Robin

文件输入流

NSMutableData *data = [NSMutableData new];
        NSInputStream *inputStream = [NSInputStream inputStreamWithFileAtPath:@"/Users/dengfang/111.txt"];
        [inputStream open];
         NSLog(@"数据读取中...");
        while(1){
            uint8_t buf[1024];
            NSInteger readLength = [inputStream read:buf maxLength:1024];
            if (readLength > 0) {
                [data appendBytes:buf length:readLength];
            } else {
                NSLog(@"未读取到数据");
                break;
            }
        }
        NSLog(@"%@" ,[data base64EncodedStringWithOptions:nil]);
    }

文件输出流

NSOutputStream *ouputStream = [NSOutputStream outputStreamToFileAtPath:@"/Users/dengfang/222.txt" append:false];
[ouputStream open];
[ouputStream write:data.bytes maxLength:data.length];
[ouputStream close];

NSThread 为objective-c 的多线程对象

#import "Saler.h"

@implementation Saler

-(Saler*) init{
    self = [super init];
    NSLog(@"init saler");
    self.ticket = [NSNumber numberWithInt:20];
    return self;
}

-(void) startSale{
    NSThread *thread = [NSThread new];
    self->thread = thread;
    [thread initWithTarget:self selector:@selector(run) object:nil];
//该访问指明调用self.run 方法作为线程运行代码 
    [thread start];
}

-(void) run{
    NSLog(@"running");
}

@end

main 函数

#import <Foundation/Foundation.h>
#import "Saler.h"

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        Saler* saler1 = [Saler new];
        Saler* saler2 = [Saler new];
        [saler1 startSale];
        [saler2 startSale];
        NSLog(@"starting");
    }
    
   
    
    return 0;
}

console output

2023-04-02 20:58:33.568419+0800 CMD[2079:186178] init saler
2023-04-02 20:58:33.568662+0800 CMD[2079:186178] init saler
2023-04-02 20:58:33.569828+0800 CMD[2079:186178] starting
2023-04-02 20:58:33.570763+0800 CMD[2079:186233] running
2023-04-02 20:58:33.570776+0800 CMD[2079:186234] running
Program ended with exit code: 0

NSDate

NSDate *date = [NSDate new];  //默认为当前日期
//NSDate *date = [NSDate date];  //调用date方法也可以
NSLog(@"print date is %@",date);

dateFormat 格式化输出

   NSDateFormatter *formatter = [NSDateFormatter new];
        
   formatter.dateFormat = @"yyyy-MM-dd HH:mm:ss z";
        
   //[formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss z"];
   
   NSString *str = [formatter stringFromDate:date];
        
   NSLog(@"print date is %@",str);

dateFormat 反格式化

NSString *dateString = @"2023-04-02 11:33:04";
        
NSDateFormatter *formatter = [NSDateFormatter new];
        
[formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
        
NSDate *date = [formatter dateFromString:dateString];
        
NSLog(@"print date is %@",date);

objective-c有自己封装的集合类 字符串类 和 数字类 大多数有不可变和可变之分

NSData 二进制byte数组

NSValue C语言基本数据类型 结构体 的NS封装

NSString /NSMutableString 字符串类

NSNumber 基本数字类

NSDecimalNumber 高精度数字类

NSArray/NSMutableArray 数组

NSDictionary/NSMutableDictionary 字典

NSSet/NSMutableSet 无序集合

https://blog.csdn.net/pishum/article/details/125152886

解决苹果开发者账户 逾期问题 (xcode不允许编译)

苹果官方文档

https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/Introduction/Introduction.html

NSLog 控制台输出

NSLog(NSString *format, …)

objective-c 文件系统依赖NSFileManager

objective-c file对象 为NSFileHandle

NSFileManager 返回的文件路径对象都是NSString

fileManager.currentDirectoryPath; //返回当前进程目录

BOOL isSuccess = [fileManager createFileAtPath:path contents:nil attributes:nil]; // 创建文件

 BOOL isDirectorySuccess = [fileManager createDirectoryAtPath:directory withIntermediateDirectories:true attributes:nil error:nil]; //创建文件夹

BOOL isRemoveSuccess = [fileManager removeItemAtPath:path error:nil];//删除文件或者文件夹

以下是读写文件文件 和文件对象操作

NSString 对应字符串

NSData 对应byte数组

NSFileHandle 对应文件对象

 NSString *homePath  = NSHomeDirectory( );
 NSString *sourcePath = [homePath stringByAppendingPathConmpone:@"testfile.text"];   
             
 NSFileHandle *fielHandle = [NSFileHandle fileHandleForUpdatingAtPath:sourcePath];   //创建文件对象
                    
 [fileHandle seekToEndOfFile];  将节点跳到文件的末尾  
        
 NSString *str = @"追加的数据"   
                
 NSData* stringData  = [str  dataUsingEncoding:NSUTF8StringEncoding];  
        
 [fileHandle writeData:stringData]; //追加写入NSData数据       
 [fileHandle closeFile]; //关闭文件对象

通过fileManager 在创建文件时写入NSData

NSString *content = @"content2";
NSData *data = [content dataUsingEncoding:NSUTF8StringEncoding];
        BOOL isSuccess = [fileManager createFileAtPath:path contents:data attributes:nil];
        if (isSuccess) {
            NSLog(@"file created");
        }else{
            NSLog(@"file not created");
        }

通过NSMutableString 写入文件

   NSMutableString *content = [NSMutableString new];
        [content appendString:@"helloworld"];
        NSString *homePath = NSHomeDirectory();
        NSString *path = [homePath stringByAppendingPathComponent: @"myfile.txt"];

        BOOL isWriteSuccess = [content writeToFile:path atomically:true encoding:NSUTF8StringEncoding error:nil];
        if (isWriteSuccess) {
            NSLog(@"content writed");
        }else{
            NSLog(@"content not writed");
        }

通过NSData 写入文件

        NSString *content = @"helloworldNSdata2";
        NSString *homePath = NSHomeDirectory();
        NSString *path = [homePath stringByAppendingPathComponent: @"myfile.txt"];

        NSData *data = [content dataUsingEncoding:NSUTF8StringEncoding];
        
        BOOL isWriteSuccess = [data writeToFile:path atomically:true];
        if (isWriteSuccess) {
            NSLog(@"content writed");
        }else{
            NSLog(@"content not writed");
        }
      

以下是流操作 NSInputStream和NSOutputStream

用文件流说明流章节比较复杂 下个章节单独说明

objective-c 没有定义自己标准输入流 输出流 异常流

需要依赖C语言的stdio

objective-c 可以完美运行C语言代码(惊呆了)

#import <Foundation/Foundation.h>
#include <stdio.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        char name[100];
        NSLog(@"Please enter the name you wish to search for ");
        scanf("%s", name);
        printf("name : %s\n",name);

        //NSString *name2 = [NSString stringWithFormat:@"%s" , name];
        NSString *name2 = [NSString stringWithCString:name encoding:NSUTF8StringEncoding]; //转化 char[] 为NSString
        NSLog(@"name2 : %@" , name2);
        
        fprintf(stdout,"abc123\n");//标准输出流输出
        fprintf(stderr,"abc123\n");//标准异常流输出
    
    }
    return 0;
}

NSProcessInfo *proc = [NSProcessInfo processInfo];

获取当前进程对象

以下是一些进程参数

        NSProcessInfo *proc = [NSProcessInfo processInfo];

        NSArray *args = [proc arguments];

        NSLog(@”args : %@” , args);

        NSDictionary *env = [proc environment];

        NSLog(@”env : %@” , env);

        int pid = [proc processIdentifier];

        NSLog(@”pid : %d” , pid);

        NSString *processName = [proc processName];

        NSLog(@”processName : %@” , processName);

        NSString *hostName = [proc hostName];

        NSLog(@”hostName : %@” , hostName);

子进程管理 通过NSTask 调用shell 启动子进程

        NSTask *task = [NSTask new];
        
        task.launchPath = @"/bin/pwd";
        task.currentDirectoryPath = NSHomeDirectory();
        //NSFileHandle *output = task.standardOutput;
        //NSFileHandle *input = task.standardInput;
        [task launch];//执行 且子进程会重定向标准输出流到主进程
        [task waitUntilExit];
        NSLog(@"end");