原地址：http://www.cnblogs.com/U-tansuo/p/ios_basis_info.html

1、获取设备类型  （Iphone/ipad 几？）

#import "sys/utsname.h"

-(NSString*)getDeviceVersion
{
    struct utsname systemInfo;
    uname(&systemInfo);
    NSString *deviceString = [NSString stringWithCString:systemInfo.machine encoding:NSUTF8StringEncoding];
    return deviceString;
}

2、获取系统时间

NSDate* date = [NSDate date];  
    NSDateFormatter* formatter = [[[NSDateFormatter alloc] init] autorelease];
    [formatter setDateFormat:@"yyyy-MM-dd HH:MM:SS"];
    [formatter stringFromDate:date];

3、获取应用版本 手机系统版本信息

UIDevice* uiDevice = [UIDevice currentDevice];  
    NSBundle* nsBundle = [NSBundle mainBundle];
    NSDictionary *infoDictionary = [nsBundle infoDictionary];
    NSString* crashInfo = [NSString stringWithFormat:@"Identifier:%@\nVersion:%@\nOS Version:%@     %@\nDate/Time:%@\nHardware Model:%@",
                        [nsBundle bundleIdentifier],
                        [infoDictionary objectForKey:@"CFBundleVersion"],
                        [uiDevice systemName],
                        [uiDevice systemVersion],
                        [self GetOnlyTime],
                        [self deviceString] ];

4、获取应用程序目录

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
    NSString *cacheDir = [paths objectAtIndex: 0];

5、创建应用程序内部文件夹

NSFileManager *fm = [NSFileManager defaultManager];
        NSDictionary *attributes = [NSDictionary dictionaryWithObject: [NSNumber numberWithUnsignedLong: 0755] forKey: NSFilePosixPermissions];
        if(![fm fileExistsAtPath:"文件路径"]){
            
            [fm createDirectoryAtPath:"文件路径"withIntermediateDirectories:YES attributes:attributes error:NULL];
        }

6、获取某个文件夹下所有文件 及删除以某后缀名结尾文件

NSFileManager *fm = [NSFileManager defaultManager];
    NSArray *contents = [fm contentsOfDirectoryAtPath:path error:NULL];
    NSEnumerator *e = [contents objectEnumerator];
    NSString *filename;
    while ((filename = [e nextObject])) {
        NSLog(@"file Name = %@",filename);
        if ([[filename pathExtension] isEqualToString:@"txt"]||[[filename pathExtension] isEqualToString:@"plcrash"]) { 
           [path stringByAppendingPathComponent:filename];
        } 
    }