接上一篇文件管理博文.我们可以用NSPathUtilities.h中包含的NSString函数和分类扩展来以兼容的方式处理路径.下面凡是有系统编程经验的童鞋都知道是啥意思了:

#import <Foundation/Foundation.h>

#define msg(...) NSLog(__VA_ARGS__)

int main(int argc, char *argv[]){
	@autoreleasepool {
		NSString *short_name = @"love.m";
		NSArray *componets;

		NSString *tmp_dir = NSTemporaryDirectory();
		msg(@"tmp_dir : %@",tmp_dir);

		NSString *full_name = [tmp_dir stringByAppendingPathComponent:short_name];
		msg(@"full_name : %@",full_name);

		NSString *ext_name = [full_name pathExtension];
		msg(@"ext_name : %@",ext_name);

		NSString *home_dir = NSHomeDirectory();
		msg(@"home_dir : %@",home_dir);

		componets = [@"/usr/local/src/linux/xxx.img" pathComponents];
		msg(@"every components : %@",componets);

		NSString *path = [@"~/src/objc_src/love.m" stringByExpandingTildeInPath];
		msg(@"expand path : %@",path);

		path = [path stringByStandardizingPath];
		msg(@"expand_way2 path : %@",path);

		msg(@"user:%@ , full_user:%@",NSUserName(),NSFullUserName());

		//last is longer...
		NSArray *list = NSSearchPathForDirectoriesInDomains(NSApplicationDirectory,\
			NSUserDomainMask,YES);
		msg(@"%@",list);

		list = NSSearchPathForDirectoriesInDomains(NSApplicationDirectory,\
			NSSystemDomainMask|NSLocalDomainMask|NSNetworkDomainMask,YES);
		msg(@"%@",list);

		NSString *full_path = [list objectAtIndex:0];
		full_path = [full_path stringByAppendingPathComponent:@"love.m"];
		msg(@"%@",full_path);
	}
	return 0;
}

以上代码含义都很清楚就不一一解释了,值得说明的是最后一个函数NSSearchPathForDirectoriesInDomains,如果第二个参数为多个单体枚举的聚集,则结果会是一个数组,代码说的很清楚了,上运行结果:

wisy@wisy-ThinkPad-X61:~/src/objc_src$ ./f
2014-07-02 15:00:14.756 f[12608] tmp_dir : /tmp/GNUstepSecure1000
2014-07-02 15:00:14.758 f[12608] full_name : /tmp/GNUstepSecure1000/love.m
2014-07-02 15:00:14.758 f[12608] ext_name : m
2014-07-02 15:00:14.759 f[12608] home_dir : /home/wisy
2014-07-02 15:00:14.759 f[12608] every components : ("/", usr, local, src, linux, "xxx.img")
2014-07-02 15:00:14.759 f[12608] expand path : /home/wisy/src/objc_src/love.m
2014-07-02 15:00:14.759 f[12608] expand_way2 path : /home/wisy/src/objc_src/love.m
2014-07-02 15:00:14.759 f[12608] user:wisy , full_user:wisy,,,
2014-07-02 15:00:14.759 f[12608] ("/home/wisy/GNUstep/Applications")
2014-07-02 15:00:14.759 f[12608] ("/usr/local/lib/GNUstep/Applications", "/usr/lib/GNUstep/Applications")
2014-07-02 15:00:14.759 f[12608] /usr/local/lib/GNUstep/Applications/love.m

接下来好玩的来鸟,何曾几时本猫都对入侵其他进程有着变态的偏执狂欲望(这在本猫的其他博文中略有体现),虽然下面代码只是查询本进程的信息,但不积跬步,何以致千里,我们慢慢来吧:

#import <Foundation/Foundation.h>

#define msg(...) NSLog(__VA_ARGS__)

int main(int argc, char *argv[]){
	@autoreleasepool {
		NSProcessInfo *proc = [NSProcessInfo processInfo];
		NSArray *args = [proc arguments];

		//msg(@"all_infos : %@",proc);
		msg(@"args : %@",args);

		NSDictionary *env = [proc environment];
		msg(@"env : %@",env);

		msg(@"pid : %d",[proc processIdentifier]);
		msg(@"process name :%@",[proc processName]);
		msg(@"hostname : %@",[proc hostName]);
		msg(@"OS type : %d",(unsigned)[proc operatingSystem]);
		msg(@"OS name : %@",[proc operatingSystemName]);
		msg(@"rand string : %@",[proc globallyUniqueString]);
		msg(@"OS ver : %@",[proc operatingSystemVersionString]);
	}
	return 0;
}

运行结果如下:

wisy@wisy-ThinkPad-X61:~/src/objc_src$ ./f 11 22 33 "aa bb cc"
2014-07-02 15:26:34.711 f[12767] args : ("./f", 11, 22, 33, "aa bb cc")
2014-07-02 15:26:34.713 f[12767] env : {"CLUTTER_IM_MODULE" = xim; COLORTERM = "gnome-terminal"; "DBUS_SESSION_BUS_ADDRESS" = 
"unix:abstract=/tmp/dbus-obtBgG4wMe"; "DEFAULTS_PATH" = "/usr/share/gconf/xfce.default.path"; "DESKTOP_SESSION" = xfce; 
DISPLAY = ":0.0"; GDMSESSION = xfce; "GDM_LANG" = "zh_CN"; "GLADE_CATALOG_PATH" = ":"; "GLADE_MODULE_PATH" = ":";
 "GLADE_PIXMAP_PATH" = ":"; "GNOME_KEYRING_CONTROL" = "/run/user/1000/keyring-1BJWxI"; "GNOME_KEYRING_PID" = 1714; 
"GTK_IM_MODULE" = fcitx; "GTK_MODULES" = "overlay-scrollbar:unity-gtk-module"; HOME = "/home/wisy"; "IM_CONFIG_PHASE" = 1;
 INSTANCE = ""; JOB = dbus; LANG = "zh_CN.UTF-8"; LANGUAGE = "zh_CN:zh"; LESSCLOSE = "/usr/bin/lesspipe %s %s";
 LESSOPEN = "| /usr/bin/lesspipe %s"; LOGNAME = wisy; "LS_COLORS" = "rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;300;36:/"; 
"UBUNTU_MENUPROXY" = 1; "UPSTART_EVENTS" = "started xsession"; "UPSTART_INSTANCE" = ""; "UPSTART_JOB" = startxfce4; 
"UPSTART_SESSION" = "unix:abstract=/com/ubuntu/upstart-session/1000/1717"; USER = wisy; "VTE_VERSION" = 3409; 
WINDOWID = 62914568; XAUTHORITY = "/home/wisy/.Xauthority"; "XDG_CONFIG_DIRS" = "/etc/xdg/xdg-xfce:/usr/share/upstart/xdg:/etc/xdg:/etc/xdg";
 "XDG_CURRENT_DESKTOP" = XFCE; "XDG_DATA_DIRS" = "/usr/share/xfce:/usr/share/xfce4:/usr/local/share/:/usr/share/:/usr/share";
 "XDG_GREETER_DATA_DIR" = "/var/lib/lightdm-data/wisy"; "XDG_MENU_PREFIX" = "xfce-"; "XDG_RUNTIME_DIR" = "/run/user/1000"; 
"XDG_SEAT" = seat0; "XDG_SEAT_PATH" = "/org/freedesktop/DisplayManager/Seat0"; "XDG_SESSION_ID" = c2; "XDG_SESSION_PATH" = 
"/org/freedesktop/DisplayManager/Session0"; "XDG_VTNR" = 7; XMODIFIERS = "@im=fcitx"; "_" = "./f";(太长截取一部分!) }
2014-07-02 15:26:34.714 f[12767] pid : 12767
2014-07-02 15:26:34.714 f[12767] process name :f
2014-07-02 15:26:34.715 f[12767] hostname : wisy-ThinkPad-X61
2014-07-02 15:26:34.715 f[12767] OS type : 100
2014-07-02 15:26:34.715 f[12767] OS name : GSGNULinuxOperatingSystem
2014-07-02 15:26:34.715 f[12767] rand string : wisy-ThinkPad-X61_31df_1963ebaa_0
2014-07-02 15:26:34.715 f[12767] OS ver : 3.13.0-24-generic

第三种文件拷贝方式，我们使用了NSFileHandle类，该类功能的一个简单流程就是：

1 打开文件 

2 对打开得文件执行I/O操作

3 关闭文件

#import <Foundation/Foundation.h>

#define msg(...) NSLog(__VA_ARGS__)

int main(int argc,char *argv[])
{
	@autoreleasepool{
		NSFileHandle *in_file,*out_file;
		NSData *buf;

		in_file = [NSFileHandle fileHandleForReadingAtPath:@"x.db"];
		if(in_file == nil){
			msg(@"open in_file failed");
			return 1;
		}

		[[NSFileManager defaultManager] createFileAtPath:@"out.db" \
			contents:nil attributes:nil];
		out_file = [NSFileHandle fileHandleForWritingAtPath:@"out.db"];
		if(out_file == nil){
			msg(@"open out_file failed");
			return 2;
		}

		//可能包含数据，先截断。
		[out_file truncateFileAtOffset:0];
		buf = [in_file readDataToEndOfFile];
		[out_file writeData:buf];

		[in_file closeFile];
		[out_file closeFile];

		msg(@"%@",[NSString stringWithContentsOfFile:@"out.db" \
			encoding:NSUTF8StringEncoding error:NULL]);
	}
	return 0;
}

NSURL类可以从网页上读取对象，这个前面有一个例子，这里不再展开说了，自己度娘哦。

最后还有一个NSBundle类，我简单看了下，类似于windows中的对程序中资源文件的定位操作，不过os x和ios资源的自包含特性更强一些；在ios中进程都在沙盒中运行读取的/目录统统都是虚拟出来的，否则全乱套鸟。貌似扯多鸟...