Chapter 5: File I/O: Further Details

Exercise 5-1

My solution is in large_file.c.

To build and test this solution:

1. Use make large_file to compile and link the code.
2. Use ./large_file test.dat 10111222333 to test this code.
3. Use stat test.dat to verify the size

The expected response is similar to:

  File: test.dat
  Size: 10111222337	Blocks: 8          IO Block: 4096   regular file
Device: fd01h/64769d	Inode: 51643046    Links: 1
Access: (0600/-rw-------)  Uid: ( 1000/ douglas)   Gid: ( 1000/ douglas)

Exercise 5-2

My solution is in ex5_2.c.

To build and test this solution:

1. Use make ex5_2 to compile and link this code.
2. Use ./test_ex5_2.sh to test this code.

The expected output is:

Contents of test file before running exercise 5-2
Line #1
Line #2
Now positioned at 0
Now positioned at 38

Contents of test file after running exercise 5-2
Line #1
Line #2
Exercise 5-2 completed

Exercise 5-3

My solution is in atomic_append.c. The real solution can be found in atomic_append.c.

To build and test this solution:

1. Use make atomic_append to compile and link this code.
2. Use ./test_atomic_append.sh to test this code.

The expected output is:

Size of test file using O_APPEND
test.dat               2000000
Size of test file without using O_APPEND
test.lst               1000089

The size of test.lst can vary

Exercise 5-4

My solution is in ex5_4.c.

To build and test this solution:

1. Use make ex5_4 to compile and link this code.
2. Use ./ex5_4 to test this code.

The expected output should be similar to:

Original file descriptors
FD (3) points to inode #51643046
FD (4) points to inode #51643592
Duplicate file descriptors
FD (5) points to inode #51643046
FD (6) points to inode #51643592
Reallocate file descriptor
FD (5) points to inode #51643592
Failed to duplicate fd #20: Bad file descriptor
Failed to duplicate fd #20 as #19: Bad file descriptor

Exercise 5-5

My solution is in ex5_5.c.

To build and test this solution:

1. Use make ex5_5 to compile and link this code.
2. Use ./ex5_5 to test this code.

The expected output should be similar to:

Original file descriptor
FD (3) points to inode #51643046, has a status of 0X8000, and an offset of 0
Duplicate file descriptor
FD (4) points to inode #51643046, has a status of 0X8000, and an offset of 0
Both file descriptors after seeking to EOF
FD (3) points to inode #51643046, has a status of 0X8000, and an offset of 2000000
FD (4) points to inode #51643046, has a status of 0X8000, and an offset of 2000000

Exercise 5-6

My solution is in ex5_6.c. The real solution can be found in multi_descriptors.c.

To build and test this solution:

1. Use make ex5_6 to compile and link this code.
2. Use ./ex5_6 to test this code.

The expected output should be:

Now doing 1 writes
The contents, after 1 writes, are:
Hello,
Now doing 2 writes
The contents, after 2 writes, are:
Hello,world 
Now doing 3 writes
The contents, after 3 writes, are:
HELLO,world 
Now doing 4 writes
The contents, after 4 writes, are:
Giddayworld 

Exercise 5-7

My solution is in ex5_7.c. This solution uses code from t_read.c.

To build and test this solution:

1. Use make ex5_7 to compile and link this code.
2. Use ./ex5_7 to test this code.

The expected output should be:

Data: inode=51643046, x=100, str[0]='X', str[99]='X'
total bytes requested: 248; bytes written: 248
Test write succeeded
Data: inode=51643046, x=100, str[0]='X', str[99]='X'
total bytes requested: 248; bytes read: 248
Test read succeeded