7.1 File System Introduction
7.1.1 file
File types: regular files, directories, files, links, files, device file, pipe file
File permissions: rwx
Access: file owner, file owner group of users with other users
7.1.2 inode
7.1.3 File System
Tree hierarchy of the system, ultimately comes down to the root file directory / on
7.2 based on file descriptor IO operations
7.2.1 Create a file, open and close
Create create 1 file
2 file open open
(File operations are not guarantee of success, so the file the operation should be carried out to detect if the error to terminate the program)
Close close 3 files
7.2.2 file read and write operations write read
Positioning lseek 7.2.3 file
Other operations 7.3 files
7.3.1 modify file attributes
1 modify file permissions
Change file owner chown fchown
(When the file operation, call chown use the path to the file name, file descriptor when the file is opened when calling fchown)
only the root user can use
Access chmod fchmod change file
2 other properties to modify the file
Rename rename
Modify the file length truncate ftruncate
Other operations 7.3.2 files
1 dup and dup2 copy the file descriptor
2 stat、fstat、lstat
stat: by pathname to access files, fstat access files through the file descriptor
When accessing a stat symbolic link file to track the end of the connection. lstat function returns only information the link itself
3 fsync all data will be stored in the buffer to be written to the file descriptor fd refresh file to be written
4 flock lock or unlock
5 fcntl view or set of files some information
6 select effective means of dealing with a plurality of file descriptors
Operation 7.4 Special files
7.4.1 Operation catalog file
Creating a directory file deletion mkdir rmdir
2 file opening and closing opendir closedir
Read readdir 3 directory file system calls to read a file directory
7.4.2 Operation of linked files
1 hard link operation
Create a link link (only root can create a link to the new file directory file)
Remove link unlink (inode link the counter is decremented)
2 symbolic links
Create symlink
Open and read the name: readlink
Operation 7.4.3 Pipeline file
pipe usually used in conjunction with fork \ dup2 \ execve and other functions used in conjunction with other programs to create a pipeline to be redirected IO's
7.4.4 Device File
/dev
Reproduced in: https: //my.oschina.net/u/204616/blog/544983