Naming a tar file with date - linux

Question

I want to name a tar file with the date, but what i try isn't working, see the code below for better explanation, and what a i have to do?
date=$( date +%Y-%m-%d_%H:%M:%S )
tar -czf ${imageName-$date}.tar.gz ${imageBasename} 2>>$ERRORLOG
The image name is a variable that stores a name of an image, like: win-ser-rdp
I had tried too:
tar -czf ${imageName}:${date}.tar.gz ${imageBasename} 2>>$ERRORLOG
Didn't work out too :(
Thanks to all the help :D

Answer 1

The problem is the : in the file name, which is treated specially by GNU tar.
On my own system, where I have a directory named foo, I get this:
$ tar zcf foo:42.tar.gz foo
tar (child): Cannot connect to foo: resolve failed
tar: Child returned status 128
tar: Error is not recoverable: exiting now
$
There doesn't seem to be any way to escape the : character -- but you can inhibit the special interpretation with the --force-local option (thanks to Daniel Serodio for pointing this out).
Colon characters in file names, though they're legal, are typically a bad idea anyway. For example, you probably wouldn't be able to access the file via scp.
Here's the relevant section from the GNU tar manual (info tar and go to section 6.1):
To specify an archive file on a device attached to a remote machine,
use the following:
--file=hostname:/dev/file-name
tar will set up the remote connection, if possible, and prompt you for
a username and password. If you use --file=#hostname:/dev/file-name,
tar will attempt to set up the remote connection using your username
as the username on the remote machine.
When I make file names that include a timestamp, I usually use YYYY-MM-DD-HHMMSS
$(date +%F-%H%M%S)
or you can use YYYY-MM-DD_HH_MM_SS if you prefer
$(date +%F-%H_%M_%S)

Answer 2

Your filenames and variables are incorrect:
${imageName-$date}
Should be
${imageName}${date}
and
${imageName}:${date}.tar.gz
is going to be interpreted as an NFS location because of the : in the name, e.g. server:filename. Replace the : with a - or other non-special character.

Answer 3

try avoiding all colons in the tarfilename, as this will make tar attempt to output to a remote file:
date=$( date +%Y%m%d_%H%M%S )
tar -czf ${imageName}-${date}.tar.gz ${imageBasename} 2>>${ERRORLOG}