Linux File time attribute inode

Linux File time attribute inode-general Linux technology-Linux programming and kernel information, the following is a detailed description. Inode of a file contains three time attributes:

Time of last access: for example, for file read Operations

Time of last modification: such as file write operations

Time of last change: modifies an attribute of a file, such as the execution permission.

A soft connection can span the file system. A hard connection can only be created in one file system. the soft connection is equivalent to a pointer, or an alias. The hard connection is directly mapped to the hard disk storage area, and shares the space on the hard disk with the original files. therefore, if you operate a hard-connected file, it is equivalent to directly operating the data on the hard disk.

Unix manages hard disks through inode. Each inode contains various information about files: Owner, permissions, and data distribution on disks. however, inode does not contain the file name. The inode information corresponding to the file is stored in the directory file. A record in each directory file contains the inode number corresponding to the file name, therefore, the directory file is equivalent to the inoing table between the file name and inode. for hard connections, multiple file names correspond to one inode, which is a many-to-one ing. For inode, it does not care about which file corresponds to it, but it records how many files correspond to it. if a file corresponding to it is deleted, the record value will be reduced by one. When it is reduced to 0, the corresponding inode resource will be released. Therefore, if a file has a hard connection, if you delete this file, the system does not actually delete it.