Shell Script to move oldest file from one directory to another directory

Question

I am new to shell scripting. I am seeking solution for it. I should have maintain the 10 files in my directory, Incase any number of file is added to this directory. I just want to move the oldest file to other directory. I gave naming Work for my directory and regular_archieve for another directory. I have tried this,

work = /home/balaji/work
regular_archieve = /home/balaji/regular_archieve
cd $work
for i in 'ls -t | sed -e '1,10d' | xargs -d '\n' rm -f'
do
 mv $i $regular_archieve
done

if [ls -t | wc -1 > 10 | mv /home/balaji/regular-archieve]
 then
   echo "more than 10 n files"
fi

mv $(ls -t /home/balaji/work | sed -e '1,10d' | tail - 1) /home/balaji/regular_archieve

But I am not able to move to file to another directory.

I am receiving this error,

mv: cannot stat 'file' : No such file or directory

Answer 1

It's never a good idea to use the output of ls for anything except viewing in a terminal. See Why not parse ls (and what to do instead)?. Instead, use find:

find /home/balaji/work/ -type f -printf '%C@\t%p\0' |
  sort -z -k1,1 -r -n |
  cut -z -f2 |
  head -z -n 10 | 
  xargs -0r echo mv -t /home/balaji/regular_archive/

This requires the GNU versions of find, sort, cut, tail, and xargs (or, at least other versions of them that support the -z option for NUL record separators).

• find uses -printf '%C@\t%p\0' to list the last-changed timestamps (%C@, in seconds since the epoch 1970-01-01 00:00:00) and filenames (%p) of all regular files. The fields are separated by a single tab (\t), and each record is separated by a NUL character (\0)
• the output of find is piped into sort to reverse sort (-r) the files numerically (-n) on the first field only (-k 1,1) -- i.e. by the timestamp.
• sort's output is piped into cut to delete the timestamp field (we no longer need it after we've finished sorting)
• cut's output is piped into head to get the first ten entries
• and finally, head's output is piped into xargs to run the mv command. This uses the GNU -t extension to mv, so that the target directory can be specified before the filenames.

Actually, this runs echo mv rather than mv, so it's a dry-run. Get rid of the echo when you're sure it's going to do what you want.

Note: This will work with any filenames, no matter what weird and annoying characters they might have in them (e.g. spaces, newlines, shell metacharacters, etc). Also, The file command has many other options which can be used to refine the search criteria.

---

If you have an old version of GNU coreutils (i.e. < version 8.25), neither cut nor head nor tail will have -z options. You can use awk instead. e.g.

find /home/balaji/work/ -type f -printf '%C@\t%p\0' |
  sort -z -k1,1 -r -n |
  awk -F '\t' 'BEGIN {RS=ORS="\0"}; NR<=10 { $1=""; $0=$0; $1=$1 ; print }' |
  xargs -0r echo mv -t /home/balaji/regular_archive/

Alternatively, you could use perl instead of awk:

 perl -F'\t' -0lane 'if ($. <= 10) {delete $F[0]; print @F}'

Answer 2

I found the another answer for the problem. The best to use find command instead of using ls command. It would help to find the oldest file and can use mv command to move to another directory.

mv $(find /home/balaji/work/ -type f -printf '%T+ %p\n' | sort | head -1) /home/balaji/regular_archieve

find – Search for files in a directory hierarchy.

/home/balaji/work/ – Search location.

/home/balaji/regular_archieve/ – Target location.

type -f – Searches only the regular files.

-printf ‘%T+ %p\n’ – Prints the file’s last modification date and time in separated by + symbol. (Eg. 2015-07-22+13:42:40.0000000000). Here, %p indicates the file name. \n indicates new line.

sort | head -n 1 – The sort command sorts the output and sends the output to head command to display the oldest file. Here, -n 1 indicates only one file i.e oldest file.

Answer 3

I'm going to ignore the obvious syntax errors in your code, and assume that you want to keep the ten most recently modified files in the ~/work directory. I'm also going to assume that you have the zsh shell available.

The following zsh shell script would move all but the ten most recently modified files from ~/work to ~/regular_archieve.

#!/bin/zsh

mv -i $HOME/work/*(.om[11,-1]) $HOME/regular_archieve

The single command in the script leaves the ten most recently modified files in ~/work, and moves the rest to ~/regular_archieve. It does this using mv and by the help of a zsh-specific globbing pattern. The pattern *(.om[11,-1]) will expand to the regular files that needs to be moved (no directories will be matched). It's the om that sorts the files by modification timestamp, and [11,-1] that picks out filename 11 through to the oldest file in this sorted list. The dot at the start of the glob qualifier .om[11,-1] makes the glob only match regular files.

If you may have many thousands of files in the directory, this may generate an "argument list too long" error. In that case, move the files individually using a loop:

#!/bin/zsh

for pathname in $HOME/work/*(.om[11,-1]); do
    mv -i $pathname $HOME/regular_archieve
done