Question

Hello, please help with the following, you're tasked with writing a shell script named “rpsm.sh”. The script reports and prints (to stdout) selected storage management information. Think of it as “RePort Storage Management”.

The easy way to describe what the script needs to do is to look at what it should display in the case where you provide incorrect parameters, or in the case where you provide “-h” for help:

Usage: ./rpsm.sh <options>< directory>

Reports selected information about specified directory tree.

Options:

-h Print this help message, i.e., “Usage: ./rpsm.sh … … (except -h and -v)”

-v Print script version information, i.e., 1.0

-u Find and list all files (just file names) with setuid set, all owners

-g Find and list all files (just file names) with setgid set, all owners

-w Find and list all files (just file names) that are world-writable

-b Find and list all files (just file names) whose size is at least 10M

-d Report directory disk usage

-i Report information about the file system

-a All of the above (except -h and -v)

There are files which match these criteria on the machine loki.ist.school.edu in the directory /home/user/CYBR. It might be easier to test your script against this directory instead of “/” for example because it will be much faster and you will not get a bunch of “permission denied” messages.

Grading rubrics:

Most of the options above are self-explanatory, but some are not, so let me provide examples for the latter case. The “-d” option should produce sorted output just like (may be more, not exactly the same as) the following. Hint: look at “du” command. Pay attention to the calculation in the last line regarding the total usage: 76 = 4+8+12+24+24 (we just need to consider all directories listed here).

user@loki:~$ ./rpsm.sh -d /home/anyuser/CYBR/files

4          /home/anyuser/CYBR/files/Perms

8          /home/anyuser/CYBR/files/EnvDemo

12        /home/anyuser/CYBR/files/BigFiles

24        /home/anyuser/CYBR/files/SomeSetgids

24        /home/anyuser/CYBR/files/SomeSetuids

76        /home/anyuser/CYBR/files

The “-i” option shows me information about the file system holding the directory I am asking about. (Hint: look at the “df” command.) It does not give me all of the information but it should look just like the following. You control the spaces or tabs between two columns, but should make it read clearly.

user@loki:~$ ./rpsm.sh -i /home/ user/CYBR

Filesystem                               Type                Use%               Mounted on

prog.ist.school.edu:/home nfs4                 52%                 /home

Again, you will want to figure out how to get the information and then also how to cut it up. Here’s another example regarding the combination of two options -i and then -d:

user@loki:~$ ./rpsm.sh -id /etc

Filesystem                                           Type                Use%               Mounted on

/dev/mapper/loki-root                         ext4                 28%                 /

4          /etc/apache2/sites-enabled

4          /etc/apparmor.d/disable

4          /etc/apparmor.d/force-complain

4          /etc/apparmor.d/tunables/multiarch.d

4          /etc/apparmor/init/network-interface-security

<more…>

You’ll note that the output for “-id” versus “-di” would be different because of the order of the command line arguments. Also note that you need to handle “-”, for instance “-id” as the same as “-i -d”. We have already covered “getopts” in this class - use it!

And “./rpsm.sh -i -d ~” is equivalent to “./rpsm.sh -id ~”, “./rpsm.sh -d -i ~” is equivalent to “./rpsm.sh -di ~”.

Answer 1

Please find the following script to find the output for given options.

Note: I have added some headers for the output to get more clarity when we use -a option

Script:

version=1.0
displayUsage()
{
echo "Usage: ./rpsm.sh <options>< directory>"
echo "Reports selected information about specified directory tree."
echo ""
echo "Options:"
echo "-h Print this help message."
echo "-v Print script version information, i.e., 1.0"
echo "-u Find and list all files (just file names) with setuid set, all owners"
echo "-g Find and list all files (just file names) with setgid set, all owners"
echo "-w Find and list all files (just file names) that are world-writable"
echo "-b Find and list all files (just file names) whose size is at least 10M"
echo "-d Report directory disk usage"
echo "-i Report information about the file system"
echo "-a All of the above (except -h and -v)"
echo ""
}

option_u()
{
   echo "list all files (just file names) with setuid set, all owners"
   find $1 -type f -perm +4000
   echo ""
}
option_g()
{
   echo "list all files (just file names) with setgid set, all owners"
   find $1 -type f -perm +2000
   echo ""
}
option_w()
{
echo "list all files (just file names) that are world-writable"
find $1 -type f -perm -o+w
   echo ""
}
option_b()
{
   echo "list all files (just file names) whose size is at least 10M"
   find $1 -type f -size +10485759
   echo ""
}
option_d()
{
echo "Report directory disk usage"
du $1
   echo ""
}

option_i()
{
   echo "Report information about the file system"
   df $1
   echo ""
}

option_a()
{
option_u $1
option_g $1
option_w $1
option_b $1
option_d $1
option_i $1

   echo ""
}
if [ $# -eq 1 ]
then
if [ "$1" == "-h" ]
then
     echo "Usage: ./rpsm.sh … … (except -h and -v)"
     exit
elif [ $1 == "-v" ]
then
     echo $version
     exit
else
     displayUsage
     exit
fi
fi

if [ $# -lt 2 ]
then
   displayUsage
   exit
fi

arg=${@:$#}

avalue=$arg

while getopts 'hvugwbdia:' OPTION; do
case "$OPTION" in
    h)
      displayUsage
      exit
      ;;

    v)
      echo $version
      exit
      ;;

    u)
      option_u $avalue
      ;;
    g)
      option_g $avalue

      ;;
    w)
      option_w $avalue
      ;;
    b)
      option_b $avalue

      ;;
    d)
      option_d $avalue

      ;;
    i)
      option_i $avalue

      ;;
    a)
      option_a $avalue

      ;;
    ?)
      displayUsage
      exit 1
      ;;
esac
done
shift "$(($OPTIND -1))"

Output:

User1> ./rpsm.sh -a
Usage: ./rpsm.sh <options>< directory>
Reports selected information about specified directory tree.

Options:
-h Print this help message.
-v Print script version information, i.e., 1.0
-u Find and list all files (just file names) with setuid set, all owners
-g Find and list all files (just file names) with setgid set, all owners
-w Find and list all files (just file names) that are world-writable
-b Find and list all files (just file names) whose size is at least 10M
-d Report directory disk usage
-i Report information about the file system
-a All of the above (except -h and -v)

User1> ./rpsm.sh -a .
list all files (just file names) with setuid set, all owners
./log

list all files (just file names) with setgid set, all owners
./log

list all files (just file names) that are world-writable
./sleep_kill.sh

list all files (just file names) whose size is at least 10M

Report directory disk usage
43252   .

Report information about the file system
Filesystem     1K-blocks     Used Available Use% Mounted on
/dev/sb2       94882804 70061400 24821404 74% /disk/wsg

User1> ./rpsm.sh -di /users/gop/
Report directory disk usage
402932 /users/gop/

Report information about the file system
Filesystem            1K-blocks       Used Available Use% Mounted on
sw.americusa.net:/disk/data/users/gop
                     2113655744 1980220160 111960768 95% /users/gop

User1>./rpsm.sh -h
Usage: ./rpsm.sh … … (except -h and -v)
User1>./rpsm.sh -v
1.0
User1>./rpsm.sh -di .
Report directory disk usage
43252   .

Report information about the file system
Filesystem     1K-blocks     Used Available Use% Mounted on
/dev/sb2       94882804 70061400 24821404 74% /disk/wsg

User1>./rpsm.sh -id .
Report information about the file system
Filesystem     1K-blocks     Used Available Use% Mounted on
/dev/sb2       94882804 70061400 24821404 74% /disk/wsg

Report directory disk usage
43252   .

User1>./rpsm.sh -a .
list all files (just file names) with setuid set, all owners
./log

list all files (just file names) with setgid set, all owners
./log

list all files (just file names) that are world-writable
./sleep_kill.sh

list all files (just file names) whose size is at least 10M

Report directory disk usage
43252   .

Report information about the file system
Filesystem     1K-blocks     Used Available Use% Mounted on
/dev/sdb2       94882804 70061400 24821404 74% /disk/wsg