Since ls is run twice, there's a race condition. If a directory is deleted in the meantime, a directory that should have been kept will be nuked. Similarly, if a directory is added in the meantime, a directory that should have been removed will persist.
There is no need to run ls twice. You can just use tail's ability to index releative to the beginning of the data, tail -n +10 versus tail -n 10. However, this approach still requires some arithmetic, since skipping the first x lines requires an option argument of x+1.
I wouldn't bother with tail. In my opinion, the simplest solution is to use sed:
Note that xargs does not play well with filenames containing whitespace or quotes. If such filenames occur, instead of xargs, a less efficient while-read loop would be necessary.
Regards,
Alister
What is the command to remove files that are generated 6 hours or older? The find and remove tells only how to remove if the file is one day old or more. Appreciate quick reply. Thanks (3 Replies)
Hi all,
I have an H80 that I'm migrating to 5.3 and prior to doing so it needed the firmware upgraded. I don't have copies of the old firmware that was on it since I was not the one who installed it and there were no copies to be found on the server itself. I installed the latest version and... (4 Replies)
Script help, I need to delete files that are older than 7 days. I do that automatically but I know that a cron job can do the job for me. Any help is greatly appreciated, as you can see, I am a DOS or WINDOWS guy. Little on UNIX. Thanks (3 Replies)
Hi All,
.profile has been replaced with a new one. I need to know the variables used in the older version of .profile. I have a session opened using the old .profile.
Is there a way that I can get the exact file.
I had some luck by using set command. But is there any way that I can get the... (5 Replies)
When I am trying to use below code of for loop on older version of ksh
it not working,and I just want to use only FOR loop
-----------------
for i in (1..5)
do
echo $i
done
-----------------
please suggest.it really stoping me.
FYI: i want to do this only by for loop (2 Replies)
Hi,
I am trying to downgrade the version of rsyslog to the older version (i.e) and when i issue the below command to check the packages i dont see the required package (i.e)
and when i try to install it is complaining about package not found.
Please advise on how to install the... (1 Reply)
Which older version and variant of Debian Linux ISO image should I use?
I attempted to install two versions of Debian Linux Operating System
onto my older full tower computer.
First version, V8.5.0, Amd64, xfce, 32Bit.
Second version V7.11.0, i386, 32Bit.
When trying to install... (1 Reply)
Hello, I'm running Ubuntu 18.04 and I would like to install libboost-python version 1.46. Currently I have installed version 1.65:
wakatana@local-machine:~$ dpkg -l | grep libboost-python
ii libboost-python-dev 1.65.1.0ubuntu1 amd64 ... (1 Reply)
Discussion started by: wakatana
1 Replies
LEARN ABOUT PLAN9
tail
TAIL(1) General Commands Manual TAIL(1)NAME
tail - deliver the last part of a file
SYNOPSIS
tail [ +-number[lbc][rf] ] [ file ]
tail [ -fr ] [ -n nlines ] [ -c ncharacters ] [ file ]
DESCRIPTION
Tail copies the named file to the standard output beginning at a designated place. If no file is named, the standard input is copied.
Copying begins at position +number measured from the beginning, or -number from the end of the input. Number is counted in lines, 1K
blocks or characters, according to the appended flag or Default is -10l (ten ell).
The further flag causes tail to print lines from the end of the file in reverse order; (follow) causes tail, after printing to the end, to
keep watch and print further data as it appears.
The second syntax is that promulgated by POSIX, where the numbers rather than the options are signed.
EXAMPLES
tail file
Print the last 10 lines of a file.
tail +0f file
Print a file, and continue to watch data accumulate as it grows.
sed 10q file
Print the first 10 lines of a file.
SOURCE
/sys/src/cmd/tail.c
BUGS
Tails relative to the end of the file are treasured up in a buffer, and thus are limited in length.
According to custom, option +number counts lines from 1, and counts blocks and characters from 0.
TAIL(1)