Question

writting a c program that does the following:

• Use Descriptor I/O operations to open the file specified as a command line argument and read at least one byte from the sequence of bytes before Hard Coded Pause Point 1. Use file system operations to remove the i-node entry for the file opened in between Hard Coded Pause Point 1 and Hard Coded Pause Point 2. You may assume the file specified on the command line will have an on disk reference count of 1. Close Descriptor 1/0 operations to the open file after Hard Coded Pause Point 2. Note: To correctly test this portion of the implementation you should perform the operations in (run your program from) a section of the file system that is not an NFS (Network File System); in a department UNIX lab environment your home directory and all subdirectories) are an NFS section of the file system. The /tmp/directory on any department environment is not an NFS section of the file system; /tmp/ is typically not an NFS section on any UNIX system. Any user can create files in /tmp/, the temporary directory Note: If you are successful, the file that you specified as a command line argument will no longer be in the file system on disk. You should test this feature with that in mind.

example output

Answer 1

• Open and Read file

#include<stdio.h>
#include<fcntl.h>

int main()
{
   char c;
   int fd1 = Open("file1.txt", O_RDONLY, 0);
   Read(fd1, &c, 1);
   printf("c = % c\n", c);
   exit(0);
}

• Close File

#include<stdio.h>
#include<fcntl.h>
int main()
{
  
   int fd1 = open("file.txt", O_RDONLY, 0);
   close(fd1);
}

• Remove file

#include<stdio.h>

int main()
{
if (remove("file1.txt") == 0)
   printf("Deleted successfully");
else
   printf("Unable to delete the file");

return 0;
}