LinuxQuestions.org - Emulating "rm" with a script

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Emulating "rm" with a script

Hello,

I want to emulate the "rm" function in UNIX so that I can send files to a specified folder rather than delete them completely, a bit like a recycle bin. I plan to write a script then set "rm" as an alias t my script, a quesry I have is how do I find out which options have precedence over others? I need to work with options -r, -R, -f, -v, and -i is there any difference between -r and -R?

I will be using getopts for my script once I figure out how to use it.

Cheers

Mike

There's been heaps of little scripts posted here that to just that;
move stuff to somewhere else.
As for the options: -r and -R are equivalent for rm
As for the precedence: if options contradict each other the last one
on the command-line gets the win.

Cheers,
Tink

Well, asking about precedence is useless - try it out. Note that /bin/rm, bash rm and zsh rm can behave differently. Logically (and for /bin/rm) precedence belongs to later switch. In zsh - to -f over -i (and -v is unknown).

Read man page and experiment.

Hi, the beginning of my code starts like this:

Code:

 #!/bin/bash

touch /$HOME/deleted

GARBAGE=/$HOME/deleted



while getopts rRfvi option; do

    case $option in

        r) while [ $# -gt "0" ]

          do

              mv $1 $GARBAGE

              shift

              done

        ;;

        R)

            echo "testing"

        ;;

        f)

            echo "testing"

        ;;

        v)

            echo "testing"

        ;;

        i)

            echo "testing"

        ;;

        *)

            echo -n "some error code to go here"

        ;;



  esac

done

So if a user selects allias (which will be rm) and the provides option -r and then a file as an argument the script should move the file or directory to my location stored in garbage, the problem is that the 'mv' command seems to be getting the option "-r" passed to it from case and resulting in error, can anyone help me with why this might be?

TIA

mike

Hi again,

I am making some progress, I have it set right now to read the argument after the the options, i still have a long way to go but I am on the right track I think, one thing I need to stop is everytime I run my script it gives an error that /$HOME/deleted is all ready created, how do I implement a stop so that it check first and then ingores if this evaluates as true?

Here is my code so far:

Code:

#!/bin/bash





function moveFiles () {



mv -f $OPTARG $GARBAGE

}





mkdir $HOME/deleted/

GARBAGE=$HOME/deleted/

NO_ARGS=0

SEPLIST="/t"





if [ $# -eq "$NO_ARGS" ]

then

  echo "rm: too few arguments"

  echo "Try \`rm --help\` for more information"

fi



while getopts :r:R:f:v:i option; do

    case $option in

        r)  SEPLIST=$OPTARG

            moveFiles

        ;;

        R)

            SEPLIST=$OPTARG

            moveFiles

        ;;

        f)

            echo "testing"

        ;;

        v)

            echo "testing"

        ;;

        i)

            echo "testing"

        ;;

        [?])

            echo  "invalid option -- $option"

            echo  "try \`rm --help\` for more information"

        ;;

  esac

done

i still need to add quite alot but can you answer the above question for now please, also notice the last part of case, I cant figure out why it will only ever spit out invalid option --"?" instead of the actually input from the user, is there awya round this?

Thanks
Once again.

Mike

if ![ -d "$HOME/deleted" ] ; then ... fi;
Yes, and it seems to me that you have too little quotes. Test frequently on paths like "~/a/a/a a a/a a a/a a a" in presence of "~/a/a/a" . Try once and you'll understand (or switch to zsh).

cheers.

how you mean? too little quote and aa/aaa/aaaa/ etc?

Thanks again.

Mike

Well, try... in some cases, when $OPT is "a/a/a a a", rm $OPT is working like
rm a/a/a a a
How many arguments do you see? 3? Is it what you wanted?

Quote:

Originally Posted by raskin

Well, try... in some cases, when $OPT is "a/a/a a a", rm $OPT is working like
rm a/a/a a a
How many arguments do you see? 3? Is it what you wanted?

its seems to be when I process anymore than one option then I get an error.

like if I try rm -rR file then it gives an error but if I use only one option it works fine.

thanks again for reply.

Mike

Read carefully man bash and man getopt. There are some pitfalls.

Hello, I have managed to fix getopt but I have a problem, the file argument that comes though getopts should be assigned to $1, but when I try send it to safeDelete() as below it complains that I am missing an argument, can any one explain why?

ta

Mike

Code:

#!/bin/bash program to emulate the "rm" command in UNIX.

#



##Initialise trash folder

if ! [ -d "$HOME/deleted" ] ; then

mkdir $HOME/deleted

fi



##Initialise variables

NO_ARGS=0

FLAG_R=0

FLAG_F=0

FLAG_I=0

FLAG_S=0

TRASH=$HOME/deleted



##functions





function safeDelete() {

mv  $1  $TRASH

}







##getopts option handling

while getopts :rRfvi o

do        case $o in



          r|R) FLAG_R=1 ;;

            f) FLAG_F=1 ;;

            s) FLAG_S=1 ;;

            i) FLAG_I=1 ;;



esac

done

shift `expr $OPTIND - 1`





##flow control

if [ $# -eq "$NO_ARGS" ] ; then

echo "rm: too few arguments"

echo "try \`rm --help\` for more information"

fi



if [ $FLAG_R -eq 1 ] ; then

safeDelete

fi

After function call $1 is function parameter, not global. So you need to a) pass "$1" to safeDelete b) read man bash c) understand that your code will do weird things on "a a" and "a".

Hi, I came up with this script:

Code:

#!bin/bash

# program to emulate the "rm" command in UNIX.





#  CREATE TRASH FOLDER



if ! [ -d "$HOME/deleted" ] ; then

    mkdir $HOME/deleted

fi



# INITIALIZE VARIABLES



NO_ARGS=0

FLAG_R=0

FLAG_F=0

FLAG_I=0

FLAG_V=0

TRASH=$HOME/deleted





# FUNCTIONS



function errorInvalidOpt() {



    echo "rm: invalid option - $o"

    echo "try \`rm -help\` for more information"

    exit 0

}





function errorTooFew() {



  echo "rm: too few arguments"

  echo "try \`rm --help\` for more information"

}



function errorNoSuch() {



  echo "rm: cannot remove $* : no such file or directory"

}



function okDelete() {



echo -n "rm: remove $* ?"

    read ANSWER

    if [ "$ANSWER" = "y" ] ; then

    mv $@ $TRASH

fi

}



function notifyDelete() {



if  [ -f  ] ; then

  echo "removing \`$*'"

  mv $@ $TRASH



fi

}



function  okNotify() {



echo -n "rm: remove $* ?"

    read ANSWER

    if [ "$ANSWER" = "y" ] ; then

    notifyDelete $@



fi

}



function delete() {

  if ! [ -f ] ; then

  errorNoSuch;

  else

  mv  $@ $TRASH

fi

}





# GETOPTS



while getopts :rRfvi o

do    case $o in



          r|R) FLAG_R=1 ;;

            f) FLAG_F=1 ;;

            v) FLAG_V=1 ;;

            i) FLAG_I=1 ;;

            *) errorInvalidOpt



      esac

done

shift `expr $OPTIND - 1`



# FLOW CONTROL



if [ "$#" -eq "$NO_ARGS" ] ; then

  errorTooFew



elif [ $FLAG_R -eq  0 ] && [ $FLAG_F -eq 0 ] && [ $FLAG_I -eq 0 ] && [ $FLAG_V -eq 0 ] ; then

  delete $@



elif [ $FLAG_R -eq  1 ] && [ $FLAG_F -eq 1 ] && [ $FLAG_I -eq 1 ] && [ $FLAG_V -eq 1 ] ; then

  okNotify $@



elif [ $FLAG_R -eq  1 ] && [ $FLAG_F -eq 1 ] && [ $FLAG_I -eq 1 ] ; then

  okNotify $@



elif [ $FLAG_F -eq 1 ] && [ $FLAG_I -eq 1 ] && [ $FLAG_V -eq 1 ] ; then

  okNotify $@



elif [ $FLAG_R -eq  1 ] && [ $FLAG_I -eq 1 ] && [ $FLAG_V -eq 1 ] ; then

  okNotify $@



elif [ $FLAG_R -eq  1 ] && [ $FLAG_V -eq 1 ] ; then

  notifyDelete $@



elif [ $FLAG_V -eq 1 ] && [ $FLAG_I -eq 1 ] ; then

  okNotify $@



elif [ $FLAG_F -eq 1 ] && [ $FLAG_I -eq 1 ] ; then

  notifyDelete $@



elif [ $FLAG_R -eq 1 ] ; then

  delete $@



elif [ $FLAG_V -eq 1 ] ; then

  notifyDelete $@



elif [ $FLAG_I -eq 1 ] ; then

  okDelete $@



elif [ $FLAG_F -eq 1 ] ; then

  delete $@

fi

how do I get rid of all the "if then else" statements and out them in a fuction based on the options flaggged?

any help would be great, I have submitted my work and passed but I know there is an easier way that what I am doing with all them statments, I just cant figure out how.

Mike

Hi,

can anyone offer any advice on the above post?

cheers

Mike