CS 332/532 – 1G- Systems Programming
HW 3
Deadline:
11/01/2020 Sunday 11:59pm
Objectives
To implement a
search
program in C program using system calls for files and
directories.
Description
Find is a popular UNIX command that traverses a file hierarchy and performs various
functions on each file in the hierarchy. The goal of this project is to implement a
program similar called
search
that supports the following functionality:
1. The program should take the directory name from where to start the file traversal as a
command-line argument and print the file hierarchy starting with the directory that is
provided by the command-line argument.
2. If the program is executed without any arguments, the program should print the file
hierarchy starting with the current directory where the program is executed. If there are no
directories in the current directory only files are listed one per line.
3. If there are other directories in the current directory then the directory name is first
displayed on a separate line and then the files in that directory are listed one-per-line with
one-tab indentation.
4. If a file is a symbolic link then the program should display the symbolic link name and in
parentheses the file name the link points to.
5. The program should also support four command-line options:
1. -S
This should list all files in the file hierarchy and print the file size next to the filename in
parenthesis.
2. -s
This should list all files in the file hierarchy with file size greater than or equal to the
value specified.
3. -f
This should list all files in the file hierarchy whose file name or directory name contains
the substring specified in the string pattern option.
4. e "" For each file that matches the search criteria the UNIX command specified with arguments must be executed.
6. The program should support not only each of these options separately but also any
combination of these options. For example: -S, -s 1024, -f jpg, -S -s 1024, -S -f jpg, -s
1024 -f jpg, -S -s 1024 -f jpg, -S -f jpg -s 1024.
7. If both -s and -f options are specified then the program should list only those files that
match both criteria. The order of the options should not matter.
Guidelines and Hints
1. The program must use function pointers similar to Figure 4.22 in the text book to
implement the functionality described above. You can use the logic and structure from
Figure 4.22 as the starting point to implement this program (make sure to go over the
program in Figure 4.22 and understand all the steps performed). However, please note that
your final program must compile and execute without any dependencies on the source
code provided by the text book. You can find a simple example on how to use function
pointers in the funcptr.c file
2. You can use the
getopt
function to process the command-line options. See
man 3
getopt
for more details and an example on how to use
getopt
function.
3. You should use a Makefile to compile and build this project and make sure to submit the
Makefile along with the rest of the source code.
4. You should upload all the source code, Makefile, and a README.txt file to Canvas. Please
do not upload any object files or executable files.
Program Documentation and Testing
1. Use appropriate names for variables and functions.
2. Use a Makefile to compile your program.
3. Include meaningful comments to indicate various operations performed by the program.
4. Programs must include the following header information within comments:
/*
Name:
BlazerId:
Project #:
To compile:
To run:
*/
5. Test your program with the sample test cases provided as well as your own test cases.
6. You can include any comments you may have about testing in the README.txt file.
Examples
Command
|
Description
|
$ ./search
|
List all files in the current directory where the program is executed.
|
$ ./search ../programs
|
List all files in the directory ../programs (relative to the current directory)
|
$./search /home/UAB/puri/CS332/programs
|
List all files in the directory /home/UAB/puri/CS332/programs (absolute path)
|
$./search -S ../programs
|
List all files in the directory ../programs along with the file size
|
$./search -s 1024
|
List all files with size >= 1024 bytes in the current directory
|
$./search -s 1024 ../programs
|
List all files with size >= 1024 bytes in the ../programs (relative to the current directory)
|
$./search -f jpg
|
List all files that have the substring “jpg” in their filename or directory name in the current directory
|
$./search -f jpg -s 1024
|
List all files that have the substring “jpg” in their filename or directory name with size >= 1024 in the current directory
|
$./search -s 1024 -f jpg
|
List all files with size >= 1024 and have the substring “jpg” in their filename or directory name in the current directory
|
$./search -S -s 1024 -f jpg
|
List all files with size >= 1024 and have the substring “jpg” in their filename or directory name in the current directory and include the file size next to the filename
|
$./search -s 1024 -e "ls -l"
|
List all files with size >= 1024 bytes in the current directory and execute the command "ls -l" on each file (ignore directories)
|
$./search -s 1024 -e "wc -l"
|
List all files that have the substring “jpg” in their filename or directory name with size >= 1024 in the current directory and execute the command "wc -l" on each file (ignore directories)
|
Sample Input and Output:
If you have the following directory structure as shown by the output of "ls -lR"
command:
Submission Guidelines
• Use best software engineering practices to design and implement this homework.
The next homework will extend the functionality provided by this program.
• Use functions and organize these functions in multiple files if necessary.
• Use a Makefile to compile and build the multiple files.
• Document you code and include instructions for compiling and executing the
program in the README.txt file.
• Test your program and describe how you tested this program in the README.txt file.
• To submit this homework :
o upload all the source files and documentation to Canvas.