I need to create a script as per below requirement

[shikhar_1]

. Create folder structure reverse to one supplied. i.e. If “/a/b/c/d/e/f” is supplied as argument to script it will create “/f/e/d/c/b/a” folder in file-system.
• Folder path to be passed to script as argument
• Add validation in script, if no arguments are supplied and for invalid argument values.
• Use functions in script (or different script files) to modularize code

Appreciating your response.

[VK2COT · Accepted solution]

Hello,

I hope this is not a school assignment :)

Just to give you a helping hand, here is the start in plain Shell:

#!/bin/sh

PATH=/bin:/usr/bin:/sbin; export PATH
MYCOMM="$(basename $0)"

helpfile () {
echo "USAGE: $MYCOMM revpath"
echo "EXAMPLE: $MYCOMM /a/b/c/d/e/f"
}

if [ $# -ne 1 ]
then
helpfile
exit 1
fi

MYPATH=$1
MYREVPATH="$(echo $MYPATH | rev)"

print "RESULT $MYREVPATH"

When run, it would do this:

# my.sh /a/b/c/d/e/f
RESULT f/e/d/c/b/a/

If you do not provide an argument:

# my.sh
USAGE: my.sh revpath
EXAMPLE: my.sh /a/b/c/d/e/f

You can extend the script in many ways.

Cheers,

VK2COT

[Richard Hepworth]

Hi,

Using perl this should do what you require:

#!/usr/bin/perl

use strict;
use warnings;
use File::Path;


my $dir = shift || die "You must specify a directory\n";
my @dirs = split('/', $dir);
my @rev_dirs = reverse(@dirs);
my $result = join('/', @rev_dirs);

mkpath("/${result}") or die "Cannot create ${result}: $!";

[shikhar_1]

Thanks for your reply.

My requirement is that directory should be created also like in reverse order.f/e/d/c/b/a/ through script only.

[shikhar_1]

And pls sxplain the script also if possible..

[shikhar_1]

Pls explain this line
MYCOMM="$(basename $0)"

[Richard Hepworth]

Shikhar,

The perl script above will create the directory in reverse order.
mkpath is used to make sure that the directory tree is created recursively.
The lines above that basically create an array of the specified paths without the '/', then reverses it, then joins it back together with '/'

# ./mkpath.pl /a/b/c
# ll -d /c/b/a
drwxr-x--- 2 root sys 96 Feb 15 08:25 /c/b/a

regards,

Richard

[shikhar_1]

Hi, I dont need perl language. I need only in shell scripting.

[Dennis Handly]

>I don't need perl language. I need only in shell scripting.

The reason you use perl because it is easier and more powerful than the shell.

To use the shell you could put the directory components in an array and then write them out in reverse order.
I suppose you could just use recursion with basename(1) and dirname(1).
function one_component {
if [ "$1" = "/" ]; then echo; return; fi
base=$(basename $1)
dir=$(dirname $1)
echo "/$base\c"
one_component $dir
}

Note: rev(1) won't work for more than 1 char component names.

[Jean-Luc Oudart]

Hi

using awk (as indicated the shell solution would not work for directory names > 1 char with rev.

I assume you already check the validity and numbers of parameters to your script:
....
echo $1 | awk -F/ '{
split($0,tab);
for(i=NF;i>0;i--) printf("/%s",tab[i]);
printf("\n");
}'

Et voila !

Regards
Jean-Luc

[James R. Ferguson]

Hi:

> Hi, I dont need perl language. I need only in shell scripting.

And, you don't need a hammer to drive a nail, either. You can use the butt end of a screwdriver, though it's harder to accomplish the task.

...JRF...