Issue with mv command in a script

Question

This must be a very simple issue to solve, but I am stuck (not a UNIX pro). I need to move a gz to a target directory, but I get a No such file or directory.

NOW=$(date +"%Y-%m-%d-%T")

DEST="~/scripts/backup"
SQL_DUMP="db_dump_$NOW.sql.gz"
echo "$SQL_DUMP"

drush sql-dump | gzip -9 > $SQL_DUMP
mv -t $DEST $SQL_DUMP

The sql.gz is created properly, only the last command does not work. How should I use it? Thanks.

Answer 1

The problem is not with your mv command.

Tilde expansion is the name for what the shell does when it replaces the ~ character with the user's home directory, e.g. /home/username. It is possible to tell the shell to not do this by quoting the tilde character. This is exactly what you have done in

DEST="~/scripts/backup"

You have assigned to DEST the string ~/scripts/backup. This directory does not actually exist. Two solutions:

• Don't quote the ~ character:

  DEST=~/scripts/backup
  

• Use $HOME instead:

  DEST="$HOME/scripts/backup"
  

A final debugging tip

Put set -x at the top of your script to turn on the xtrace option. If you had done that you would have seen that the mv command was using the wrong directory, ~/scripts/backup instead of /home/yourname/scripts/backup.

Answer 2

Read mv manual

SYNOPSIS
    mv [SOURCE] [DEST]

And you may want to check if $DEST already exist:

if [ -d ${DEST} ]; then
    do something
fi

If not, use mkdir with -p as parameter to make parent directories.

...
else
    mkdir -p ${DEST}
fi