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:
Code:
FILENAME=$(ls ${DEST_LOCATION}/${FILES} | sort -r -k 4n | head -1)
ls ${DEST_LOCATION}/${FILES} | grep -v ${FILENAME} | xargs rm -rf"
do what you want, the commands:
Code:
last=""
for i in ${DEST_LOCATION}/${FILES}
do if [ "$last" != "" ]
then rm "$last"
fi
last="$i"
done
or equivalently:
Code:
last="";for i in ${DEST_LOCATION}/${FILES};do if [ "$last" != "" ];then rm "$last";fi;last="$i";done
will do the same thing in the shell just using rm without needing to call ls twice, sort, head, grep, or xargs.
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
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. ${CM_ENV_FILE}
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$AUDIT_DIR -type f -mtime +$AUDIT_EXPIRE \ -exec rm {} > /dev/null 2>&1 \;
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sed '$!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..
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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:
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Hello everyone,
I found this command line in a website:
perl -pi.bak -we's/\z/Your new line\n/ if $. == 2;' your_text_file.txt
With this command line you can insert a new line anywhere you want in a text without overwriting what's in it.
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Hi,
Could you please explain me the below statement -- phrase wise.
sed -e :a -e '$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.
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