Like Don Cragun suggested, you would need to specify a field separator for sort which in this case would probably be an underscore ( _ )
The number in this case appears to consist of two parts:
8 numbers for date, and the rest of the numbers for sequence.
If that is correct that would mean something like:
It is probably best to make sure the field number is not influenced by underscores in the path name, so:
So then the sort would become:
One thing to keep in mind is that if there are too many files in $FILES then ls would break because the total line length would be exceeded...
The contents of pipe1 are:
And the contents of pipe2 are:
What I am attempting to do is identify the newest file and delete any other than this, which I think is working using the combination of
and
.
I'm sorry, but this just is not possible. The head -1 should print the 1st line in pipe2. But:
does not appear in pipe2 nor in pipe1!
But, whether it is there or not, the -k option and its option argument (whether it is 4n or 4,4n have absolutely no effect in this pipeline since sort is given input that only contains one field.
The files in pipe1 and pipe2 are in alphabetic and (assuming the last part of the name before the .CSV is the date in YYYYMMDDhhmm[ss] format) in date order with file1 in increasing order and file2 in reverse order.
Note that if the commands:
do what you want, the commands:
or equivalently:
will do the same thing in the shell just using rm without needing to call ls twice, sort, head, grep, or xargs.
Note also that if
is present with the files listed in file1 and file2, all of the files shown in file1 and file2 will be removed just leaving
.
Last edited by Don Cragun; 01-21-2013 at 11:01 AM..
Reason: Change *.CSV* to the list actually used in the original scripts
Thank you Don & Scrutinizer, it's has been very valuable. Is there a way to do the above but base the surviving file on the created date, not alphabetically?
Last edited by jimbojames; 01-21-2013 at 05:50 PM..
Hi Folks,
I am struggling to understand nawk command which was used by another developer.
Can you please explain what each character or string is doing here below:
if ; then (3 Replies)
I tried to use sort utility and typed sort --help, read one of lines; its -k option, and part of it:
I am really not getting it
Anyone do me a useful favor to save me out of my ignorance ?
Please use correct tags as required by forum rules! (1 Reply)
Hi All
I ran a script in Linux.
In the script i have lines like
&& echo "Failed: Missing ${CM_ENV_FILE} \n" && return 1
. ${CM_ENV_FILE}
Where CM_ENV_FILE = /data/ds/dpr_ebicm_uat//etl/cm3_0/entities/BBME/parameters/cm.env
But its taking this path... (1 Reply)
can anyone please tell me what does this expression means , i am under probation and need some explanation :)
$AUDIT_DIR -type f -mtime +$AUDIT_EXPIRE \ -exec rm {} > /dev/null 2>&1 \;
AUDIT_DIR="/var/log/"
AUDIT_EXPIRE='30'
Please use code tags! (4 Replies)
sed '$!N; /^\(.*\)\n\1$/!P; D'
i found this file which removes duplicates irrespective for sorted or unsorted file. keep first occurance and remove the further occurances.
can any1 explain how this is working..
i need to remove duplicates following file. duplicate criteria is not the... (3 Replies)
Hi to all.
I'm trying to sort this with the Unix command sort.
user1:12345678:3.5:2.5:8:1:2:3
user2:12345679:4.5:3.5:8:1:3:2
user3:12345687:5.5:2.5:6:1:3:2
user4:12345670:5.5:2.5:5:3:2:1
user5:12345671:2.5:5.5:7:2:3:1
I need to get this:
user3:12345687:5.5:2.5:6:1:3:2... (7 Replies)
Hello everyone,
I found this command line in a website:
perl -pi.bak -we's/\z/Your new line\n/ if $. == 2;' your_text_file.txt
With this command line you can insert a new line anywhere you want in a text without overwriting what's in it.
-p causes perl to assume a loop around your... (4 Replies)
Hi,
Could you please explain me the below statement -- phrase wise.
sed -e :a -e '$q;N;'$cnt',$D;ba' abc.txt > xyz.txt
if suppose $cnt contains value: 10
it copies last 9 lines of abc.txt to xyz.txt
why it is copying last 9 rather than 10.
and also what is ba and $D over there in... (4 Replies)