[SOLVED] ln -s sub directories bash script..

atmos1234 · 05-28-2012, 05:35 AM

Hi all,

i use this function in my script. The problem i have it doesn't pick up sub directories. Can someone tell me what im doing wrong by example? It works exactly how it should with files.. I tried some stuff but it cant get it to work.

Code:

function _recurselink {

target="/tempcomplete"
source="/home/complete"  

    if [[ ! -d "$target"/"$1" ]]
        then
       
    mkdir -p "$target"/"${1// /.}"
    fi
        for item in "$source"/"$1"/*
        do

                if [[ -f "$item" ]]
                   then
                      ln -s "$item" "$target"/"${1// /.}"
                fi
                     if [[ -d "$item" ]]
                        then
                          _recurselink "$item"
                     fi
        done
}

grail · 05-28-2012, 06:18 AM

Try placing set -xv at the start of your script and look at the output to see where your code is coming unstuck.

colucix · 05-28-2012, 08:30 AM

One problem can be that since the first iteration, the argument of _recurselink is an absolute path since item is

Code:

"$source"/"$1"/something

as assigned by the for loop. At this point the full path of the source is added again and any test of existence of files or directories fails. For example, if you call the function with testdir the item at the first recursion becomes:

Code:

/home/complete//home/complete/testdir

this directory obviously doesn't exist and the function terminates gracefully.

colucix · 05-28-2012, 08:41 AM

Unless this is a programming exercise or compatibility with other *nix systems is required, an alternative is a single cp command with the proper options:

Code:

cp -Rs /home/complete /tempcomplete

where the -s option tells to link files symbolically instead of copying. The directory structure is preserved and recursion is performed by the option -R. Notice that the absolute path of the source is mandatory, otherwise symbolic links cannot be created, since relative paths are referred to your current working directory and not to the destination.

atmos1234 · 05-28-2012, 08:42 AM

Quote:

Originally Posted by colucix

One problem can be that since the first iteration, the argument of _recurselink is an absolute path since item is

Code:

"$source"/"$1"/something

as assigned by the for loop. At this point the full path of the source is added again and any test of existence of files or directories fails. For example, if you call the function with testdir the item at the first recursion becomes:

Code:

/home/complete//home/complete/testdir

this directory obviously doesn't exist and the function terminates gracefully.

Yes, this is what happens.. But if i remove $source then nothing happens..
Do you know How can i solve this? I need it for files but also for files in a subdirectory.

Thank you for taking the time to explain.

colucix · 05-28-2012, 09:33 AM

I noticed you posted almost at the same time of my add-on and maybe you missed my last post about the cp alternative. Is it suitable for you?

colucix · 05-28-2012, 09:53 AM

Anyway, here is a working recursive function:

Code:

function _recurselink {
  mkdir -p "${2// /.}"
  for item in "$1"/*
  do
    if [[ -f "$item" ]]
    then
      ln -s "$item" "${2// /.}"
    fi
    if [[ -d "$item" ]]
    then
      _recurselink "$item" "$2/${item##*/}"
    fi
  done
}

It is independent from the actual path (notice it does not define source or target) and you have to call it with two arguments, the source directory (absolute path) and the target directory, exactly the same as the suggested cp command:

Code:

_recurselink /home/complete /tempcomplete

Also notice that using the -p option of mkdir makes the test for the existence of the directory not necessary.

atmos1234 · 05-28-2012, 01:09 PM

Works great!! I never would thought of this.. Thank alot!