Very Computer

Is there a good script to maintain the earliest and latest dated files and
delete the others?  As I edit my files, I automatically create
a unique backup named with the date and time.  Thanks for any pointers.

-rwx-- 1 eric ipusers  893 Apr 19 16:43 ..login.960419.16:43~.gz*  KEEP
-rwx-- 1 eric ipusers  890 Apr 20 11:46 ..login.960420.11:46~.gz*  KILL
-rwx-- 1 eric ipusers 1151 Apr 20 11:58 ..login.960420.11:58~.gz*  KILL
-rwx-- 1 eric ipusers 1158 Apr 20 12:03 ..login.960420.12:03~.gz*  KILL
-rwx-- 1 eric ipusers 1193 Apr 20 12:10 ..login.960420.12:10~.gz*  KILL
-rwx-- 1 eric ipusers 1193 Apr 22 17:02 ..login.960422.17:02~.gz*  KILL
-rwx-- 1 eric ipusers 1196 Apr 26 15:51 ..login.960426.15:51~.gz*  KEEP

--

--

 > Is there a good script to maintain the earliest and latest
 > dated files and delete the others?  As I edit my files, I
 > automatically create a unique backup named with the date and
 > time.  Thanks for any pointers.

 > -rwx-- 1 eric ipusers  893 Apr 19 16:43 ..login.960419.16:43~.gz*  KEEP
 > -rwx-- 1 eric ipusers  890 Apr 20 11:46 ..login.960420.11:46~.gz*  KILL
 > -rwx-- 1 eric ipusers 1151 Apr 20 11:58 ..login.960420.11:58~.gz*  KILL
 > -rwx-- 1 eric ipusers 1158 Apr 20 12:03 ..login.960420.12:03~.gz*  KILL
 > -rwx-- 1 eric ipusers 1193 Apr 20 12:10 ..login.960420.12:10~.gz*  KILL
 > -rwx-- 1 eric ipusers 1193 Apr 22 17:02 ..login.960422.17:02~.gz*  KILL
 > -rwx-- 1 eric ipusers 1196 Apr 26 15:51 ..login.960426.15:51~.gz*  KEEP

    # rmbackups - remove unused backup files
    : ${BackupDir:=`pwd`}

    n=`ls -t "$BackupDir" | wc -l`
    n=`expr ${n:-0} - 1`
    [ $n -gt 1 ] &&
        ls -t "$BackupDir" | sed -n "2,${n}p" | xargs rm

Be careful - this example actually deletes files. It does not
care for the name of the backup file, only for the time of the
last modification ("ls -t").

Heiner
--
     -------------------------------------------------------------

   / BinTec Communications      / mine, not BinTec's --       /
  / Willstaetter Str. 30 ------- ...even if they should be ;-)/

------------------------------------------------------------

: Is there a good script to maintain the earliest and latest dated files and
: delete the others?  As I edit my files, I automatically create
: a unique backup named with the date and time.  Thanks for any pointers.
: -rwx-- 1 eric ipusers  893 Apr 19 16:43 ..login.960419.16:43~.gz*  KEEP
: -rwx-- 1 eric ipusers  890 Apr 20 11:46 ..login.960420.11:46~.gz*  KILL
: -rwx-- 1 eric ipusers 1151 Apr 20 11:58 ..login.960420.11:58~.gz*  KILL
: -rwx-- 1 eric ipusers 1158 Apr 20 12:03 ..login.960420.12:03~.gz*  KILL
: -rwx-- 1 eric ipusers 1193 Apr 20 12:10 ..login.960420.12:10~.gz*  KILL
: -rwx-- 1 eric ipusers 1193 Apr 22 17:02 ..login.960422.17:02~.gz*  KILL
: -rwx-- 1 eric ipusers 1196 Apr 26 15:51 ..login.960426.15:51~.gz*  KEEP

This will print out the "rm" commands to use, for the case of the
specific files labelled above. Enclose in an "eval" builtin to then
execute these commands (make sure to backslash characters having
significance to the shell, like the dollar sign below). The fundamental
idea is demonstrated below and making into a robust script is "left as
an exercise to the student."

ls -t ..login.9604* | sed -n '
1d
$d
s/^/rm -f /p'

-Brian
--
   ,---.     ,---.     ,---.     ,---.     ,---.     ,---.     ,---.  
  /  _  \   /  _  \   /  _  \   /  _  \   /  _  \   /  _  \   /  _  \  

__,'   `.___,'   `.___,'   `.___,'   `.___,'   `.___,'   `.___,'   `.__

    cd ${BackupDir:-.} &&
    ls -t | sed -e '1d' -e '$d' | xargs rm -f delete_me

(Pet peeve: why isn't there an option to xargs to tell it not to execute
the command if it receives no input?)
--

UniSoft Limited, London, England.

|> (Pet peeve: why isn't there an option to xargs to tell it not to execute
|> the command if it receives no input?)

Use GNU xargs (-r --no-run-if-empty).
--
Andreas Schwab                                      "And now for something