The most common file read/write

Read/write operations on common files, as shown in the following example:

# Include <stdio. h>
# Include <fcntl. h>
# Include <unistd. h>
# Include <stdlib. h>
# Include <sys/STAT. h>

Int main (){

Char Buf [10];
Int N, FD;
Struct stat file_stat;

Stat ("test", & file_stat );
Printf ("file device number: % d \ n", (INT) file_stat.st_dev );
Printf ("node: % d \ n", (INT) file_stat.st_ino );
Printf ("folder type: % d \ n", (INT) file_stat.st_mode );
Printf ("Number of hard links: % d \ n", (INT) file_stat.st_nlink );
Return 0;

/**
* Read from the standard input by reading the file and write it back to the standard output.
*/
N = read (stdin_fileno, Buf, 10 );
If (n <0 ){
Perror ("read error ");
Exit (1 );
}
Write (stdout_fileno, Buf, N );

/**
* Create an object
*/
FD = open ("test", o_creat, s_irwxu );
Close (FD );

/**
* Write characters to files
*/
FD = open ("test", o_wronly );
N = write (FD, Buf, sizeof (BUF ));
Close (FD );

/**
* Open a common file to read characters
*/
FD = open ("test", o_rdonly );
N = read (FD, Buf, sizeof (BUF ));
Printf ("% s \ n", Buf );
Close (FD );

/**
* Location of the relocation operation
*/
FD = open ("test", o_wronly );
N = lseek (FD, 10, seek_set );
N = write (FD, Buf, sizeof (BUF ));
Close (FD );

/**
* Truncate the file (variable length is also available)
*/
FD = open ("test", o_rdwr );
N = ftruncate (FD, 14 );
Close (FD );

Return 0;
}