[SOLVED] copy with appended timestamp

solidbulk · 08-31-2022, 12:43 AM

I am trying to create a .sh file that will copy a file and append the timestamp right before the extension.

I am trying the following.

#!/bin/bash
cp -p /home/oracle/Desktop/folder_1/movefile.txt /home/oracle/Desktop/folder_2/movefile{,"-$(date +"%Y%m%d%H%M%S")"}.txt

the error I am seeing when I run from the terminal is

bash archive.sh
cp: target ‘/home/oracle/Desktop/folder_2/movefile-20220831014047.txt’ is not a directory

any help or pointers will be appreciated.

pan64 · 08-31-2022, 02:32 AM

use set -xv before executing this command and you will see how is it interpreted by the shell.
And you will see your command is expanded into 5 parts (something like this):

Code:

cp                                                        # the command itself
-p                                                        # a flag
/home/oracle/Desktop/folder_1/movefile.txt                # first argument
/home/oracle/Desktop/folder_2/movefile.txt                # second argument
/home/oracle/Desktop/folder_2/movefile-20220831014047.txt # third

Keith Hedger · 08-31-2022, 05:21 AM

remove the curly braces eg

Code:

cp -p a/b/c/xxx.txt "a/b/xxx-$(date +"%Y%m%d%H%M%S").txt"
keithhedger@LFSInitDev [ /tmp ]$ ls a/b
c  xxx-20220831111919.txt

michaelk · 08-31-2022, 08:45 AM

To elaborate on the previous posts.

Code:

/path/movefile{,"-$(date +"%Y%m%d%H%M%S")"}.txt

The {} is called brace expansion. As an example a{b,c}d will expand to
abd and acd

Or in your case a{,c}d expands to
ad and acd
i.e.
/home/oracle/Desktop/folder_2/movefile.txt
and
/home/oracle/Desktop/folder_2/movefile-20220831014047.txt

which does not produce the intended results. In your case brace expansion is not necessary and you can just combine a command substitution i.e. $() together in a fixed string normally without needing anything else as in post #3.

solidbulk · 09-04-2022, 12:01 AM

pan64 Thanks for the tip that will help me see what is going on.
Keith Hedger That's the fix thank you.
michaelk Thanks for the clarification.

Thank you .