COP 4225 Advanced Unix Programming
Project 4

Description

        In this project, you are required to write a Unix/C program myfind to find a file (find_file) under a directory (search_dir ). The syntax of myfind is

                       myfind search_dir  find_file

Note that the find_file itself cound be a directory. The exact location of search_file can be generalized as "search_dir/dir₁/dir₂/....../dir_n/find_file", where n is an non-negative integer. If more than one find_files exist, myfind should return the one with a lowest n.

 If find_file exists, the standard output of your program should give the detailed information of this file, with the following format:

                      location                                                file modes                             file size            link count                    
                      search_dir/dir₁/dir₂/....../dir_n/find_file     drwx------                           4096               1

and a subsequent "echo $?" after executing myfind should return 0.

If the file does not exist, there should be no output and a subsequent "echo $?" after executing myfind should return 1. 

If the permission of search_dir, dir_i, or find_file does not allow the command to complete, there should be no output and a subsequent "echo $?" after executing myfind should return 2.   And the program should print out "permission denied: search_dir/dir₁/dir₂/....../dir_i[/find_file]" on the standard error output, where dir_i or find_file is the first blocking node along the search.

Furthermore, in this project, a directory of search_dir or dir_i (i=1, 2, ... n-1) along the search path is defined to be an ambiguous node if it has more than one child directories. If so, no matter  whether find_file exists or not, there should be no standard output and a subsequent "echo $?" after executing myfind should return 3. And the program should print out "ambiguous: search_dir/dir₁/dir₂/....../dir_i" on the standard error output, where dir_i is the first ambiguous node along the search. That is, the program stops searching when it encounters a "subdirectory fork". 

Submission

• Due Dec 7, 2004.
• Send the myfind .c file as an email attachment to czhang AT cs dot fiu dot edu (with email title: COP 4225 Project 4).
• Bring a hard copy to the class.
• A shell script will be used to test your program. The output of your program should follow the specification exactly.

Grading

p4_a --- 1 --- 2 --- 3 --- 4
                                |
                              file

p4_b --- 1 --- 2 (unreadable)

p4_c --- 1 --- 2 --- 3 --- 4.1
                       |        |        
                   file2     4.2