Objective-C:启用/禁用文件读取(chmod ar)

Question

使用Objective-C,如何为所有用户提供/获取读取文件的权限？

我需要的东西,具有相同的效果chmod a-r和chmod a+r.

谢谢!

Answer 1

您是否也熟悉chmod 755 file更改权限的方法？使用八进制数？

NSMutableDictionary *dict = [[NSMutableDictionary alloc] init]; 

//Prefixing zero is octal.
int readPermission = 04;
int writePermission = 02;
int executePermission = 01;

//End multiplication is to shift digits left.
int owner = (readPermission | writePermission | executePermission) * (8 * 8);   //7
int group = (readPermission)                                       * (8);       //4 
int other = (executePermission);                                                //1

int permissions = owner + group + other;  //0741

[dict setObject:[NSNumber numberWithInt:permissions] forKey:NSFilePosixPermissions]; 

NSError *error = nil;
[[NSFileManager defaultManager] setAttributes:dict ofItemAtPath:[file path] error:&error];