Question

I am trying to make a bash script that moves a file or directory from source directory to destination directory and puts a symlink to it into source directory.

So, <source_path> can be a file or directory, <destination_dir_path> is the directory where I want the original moved to.

Sample usage:

$ mvln /source_dir/file.txt /destination_dir/
OR
$ mvln /source_dir/dir_I_want_to_move/ /destination_dir/

This is what I have managed to put together, but it does not work properly.
It works only if source is a directory, otherwise mv returns an error:

mv: unable to rename `/source_dir/some_file.txt': Not a directory

And the directory is not moved into destination_directory but only its contents are moved.

#!/bin/bash

SCRIPT_NAME='mvln'
USAGE_STRING='usage: '$SCRIPT_NAME' <source_path> <destination_dir_path>'

# Show usage and exit with status
show_usage_and_exit () {
    echo $USAGE_STRING
    exit 1
}

# ERROR file does not exist
no_file () {
    echo $SCRIPT_NAME': '$1': No such file or directory'
    exit 2
}

# Check syntax
if [ $# -ne 2 ]; then
    show_usage_and_exit
fi

# Check file existence
if [ ! -e "$1" ]; then
    no_file $1
fi

# Get paths
source_path=$1
destination_path=$2

# Check that destination ends with a slash
[[ $destination_path != */ ]] && destination_path="$destination_path"/

# Move source
mv "$source_path" "$destination_path"

# Get original path
original_path=$destination_path$(basename $source_path)

# Create symlink in source dir
ln -s "$original_path" "${source_path%/}"

Can some one please help?

Answer 1

The problem is that $destination_path refers to a directory that doesn’t exist. Something like this:

mv /path/to/file.txt /path/to/non/existent/directory/

returns an error, and

mv /path/to/directory/ /path/to/non/existent/directory/

will rename /path/to/directory/ to /path/to/non/existent/directory/ (provided that /path/to/non/existent/ is an existent directory, just without a subfolder named directory).

If you are expecting that $destination_path doesn’t already exist, then you can add a mkdir command:

mkdir "$destination_path"
mv "$source_path" "$destination_path"

if you’re expecting that it might not exist, then you can add it conditionally:

[[ -d "$destination_path" ]] || mkdir "$destination_path"
mv "$source_path" "$destination_path"

and if you’re expecting that it does exist, then you have some debugging to do!

(By the way, depending on your exact situation, you might find mkdir -p to be helpful. It recursively creates a directory and all necessary parent directories, and it doesn’t mind if the directory already exists.)