Screen Saver（屏幕保护设置）mac os

1. 在终端更改屏幕保护设置（这个命令要切换到用户态使用）

//不过这个似乎只能设置系统里有的时间才能生效，以s为单位
defaults -currentHost write com.apple.screensaver idleTime 60
defaults -currentHost read com.apple.screensaver idleTime//必须read，不然只有重启才能生效

参考：https://light0457.github.io/2016/08/13/ShadowsocksAutoGrabber/

2. 可以从代码中对相应文件下的对应参数进行调整，重启Mac后，屏保相应参数则会对应更新。
   文件地址：

~/Library/Preferences/ByHost/com.apple.screensaver.××××××.plist

相关参数：

idleTime 等待时间：指定时间（以秒为单位）后，则会显示屏保程序，设定为0时，则不显示屏保

原文链接：[https://www.cnblogs.com/innovator/p/3958358.html]https://www.cnblogs.com/innovator/p/3958358.html]

3.更改从屏保或睡眠中唤醒是否需要密码，且多久后需要密码

 if([systemVersion compare:version] == NSOrderedAscending) {//小于10.13版本
        NSString *askForPassword = @"1";
        NSString *str1 = @"defaults -currentHost write com.apple.screensaver askForPassword -int ";
        str1 = [str1 stringByAppendingString:askForPassword];
        NSString *command1 = [NSString stringWithFormat:@"su - %@ -c \"%@\"", userName, str1];
        NSArray *arguments1 = [NSArray arrayWithObjects:@"-c", command1, nil];
        NSTask *task1 = [[NSTask alloc] init];
        [task1 setLaunchPath:@"/bin/sh"];
        [task1 setArguments:arguments1];
        [task1 launch];
        [task1 waitUntilExit];
        int st1 = [task1 terminationStatus];
        
        NSString *askForPasswordDelay = @"1";
        NSString *str2 = @"defaults -currentHost write com.apple.screensaver askForPasswordDelay -int ";
        str2 = [str2 stringByAppendingString:askForPasswordDelay];
        NSString *command2 = [NSString stringWithFormat:@"su - %@ -c \"%@\"", userName, str2];
        NSArray *arguments2 = [NSArray arrayWithObjects:@"-c", command2, nil];
        NSTask *task2 = [[NSTask alloc] init];
        [task2 setLaunchPath:@"/bin/sh"];
        [task2 setArguments:arguments2];
        [task2 launch];
        [task2 waitUntilExit];
        int st2 = [task2 terminationStatus];
        if (st1 == 0 && st2 == 0) {
            return YES;
        } else {
            return NO;
        }
        
    }else {
        NSString *isNeedPwd = @"true";
        NSString *command3 = @"osascript -e 'tell application \"System Events\" to set require password to wake of security preferences to ";
        command3 = [command3 stringByAppendingString:isNeedPwd];
        command3 = [command3 stringByAppendingString:@"'"];
        NSArray *arguments3 = [NSArray arrayWithObjects:@"-c", command3, nil];
        NSTask *task3 = [[NSTask alloc] init];
        [task3 setLaunchPath:@"/bin/sh"];
        [task3 setArguments:arguments3];
        [task3 launch];
        [task3 waitUntilExit];
        int st3 = [task3 terminationStatus];
        if (st3 == 0) {
            return YES;
        } else {
            return NO;
        }
        
    }

4.http://blog.sina.com.cn/s/blog_8343bc050102v57l.html