Unix Systems Programming: Lab 2 - Stat, Make & file I/O

Purpose and Rationale

Resources

FAQ (submission instructions and other useful stuff)

If you are not on piazza, go to the course syllabus and register.

Lecture 2 is the primary source for this lab.

All work should be done on a machine in the department's Linux cluster. You can refer to ssh for more information on how to log into a remote machine.

Marks Distribution

NOTE:  If your code does not compile, it cannot be graded, and you will receive a 0 for that portion of the lab.

LAB 2

• EXERCISE 1: Implement the stat command in C. Write a C program called my_stat that implements the default behavior of the UNIX stat command.  Your output should exactly match the default output of the stat command on the cluster.  For instance:
  
  File: "/usr/bin/stat"
  Size: 7212          Blocks: 16         IO Block: 4096   Regular File
  Device: 303h/771d    Inode: 311082      Links: 1   
  Access: (0755/-rwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
  Access: Wed Jul 10 23:00:30 2002
  Modify: Wed Aug  8 10:49:41 2001
  Change: Thu Apr  4 12:34:28 2002
  
  Hint: "man stat" and "man 2 stat".  Again, the output of your stat program with the option should match the output of the original stat program.  For those of you using Molay's text, you will find his discussion on the stat call on pages 82ff quite helpful in using the stat call and formatting the output correctly.

  For extra credit (5 points): Implement handling of any one of the following two flags:
  -L (follow Links)
  -c --format (implement a subset of 5 of the formatting options (your choice which 5))

  DELIVERABLES: your source file(s) (e.g., mystat.c), a makefile, and a README as described below in Deliverables

• EXERCISE 2: Implement a simplified version of the UNIX program "cp" , which copies one file to another. Call the file filecopy.c.  This version copies only files, it does not permit the second argument to be a directory. We also ignore all options in command "filecopy".

  Please follow these steps:

  • Read the chapters in the Kerrisk text as per the syllabus.
  • Read and understand these examples: read.c and write.c; (man 2 read; man 2 write if necessary)
  • Use Low-level File Access functions such as creat, open, read, write, close, etc.) to implement this command
  • You must handle the situation when the second argument is the same as the first, i.e., you should not allow a file to be copied over itself.  Handle this situation intelligently.
  • Acctually, you only need to integrate above examples and add only serveral lines.

  DELIVERABLES: your source file(s) (e.g., filecopy.c), a makefile, and a README as described below in Deliverables

Deliverables

Carefully follow the steps below.

1. Please create subdirectories ex1 and ex2, and place each exercise's materials in its respective directory as described below:
   
   
   • Directory ex1 will include at least three files.
     • Source code files: You may organize your files anyway you like.
     • Makefile: it must build your executable named mystat when we type make on the command line.
     • README : This file must include the correct command line syntax (including the available option in you do the bonus), a brief explanation of your command (including the extra functionality if you do the bonus) and the transcript of one example of your command in the default mode (if you are doing the bonus option, submit a second example showing your option at work.)
       
       
   • Directory ex2 will include at least three files.
     • Source code files: You may organize your files anyway you like.
     • Makefile: it must build your executable name filecopy when we type make on the command line.
     • README : This file must include the correct command line syntax of filecopy and a brief explanation of what it does. There is no need to send a transcript of it in action.
       
       
     • When you are finished with your directory you will create a compressed archive file using tar (this utility stores your directory as a single file, then compresses its size.)
              tar -czvf   username.lab2.tgz   username.lab2
       
     
     
     • You will email your file to our TA as an attachment. He will send an acknowledgement that your assignment has been received.
       

       To	Nicholas Flees (nickflees@uchicago.edu)
       Attachment	username.lab2.tgz
       Subject	CSPP51081-lab2

---