I have a string "abc" and I am greping it in 15 files in my directory in shell. When I grep "abc" in my 15 files than it returns me the whole line of the files in which its present like this:
abc 0.2 9.0 abc 0.01 8.0 abc 0.06 9.4 abc 0.02 8.7 Now I want this output to be sorted in ascending order according to the second column.
So I wrote the command like this:
grep "abc" *.txt | sort -nr -t_ -k2 but the above command is not working and I don't know why.
Your command is not working because you don't have underscores separating the columns; further, you wanted the data ascending but you told it to sort in reverse (descending) order. Use:
grep "abc" *.txt | sort -n -k 2 Or:
grep "abc" *.txt | sort -k 2n Note that if there are multiple files, your grep output will be prefixed with a file name. You will have to decide whether that matters. It only screws things up if there are spaces in any of the file names. The -h option to grep suppresses the file names.
I suggest to delete -t_ parameter, because as I see you use spaces as separator, not underscore. After that it works for me:
$ cat t | sort -n -k2 abc 0.01 8.0 abc 0.02 8.7 abc 0.06 9.4 abc 0.2 9.0 Updated: and yes, as @jonathan-leffler said you also should omit -r option for sorting in ascending order.
You can replace your entire script, including the call to grep, with one call to awk
awk '/abc/{a[$2,i++]=$0}END{l=asorti(a,b);for(i=1;i<=l;i++)print a[b[i]]}' *.txt $ ls *.txt four.txt one.txt three.txt two.txt $ cat *.txt abc 0.02 8.3 foo abc 0.06 9.4 bar blah blah abc 0.2 9.0 blah abc 0.01 8.0 blah abc 0.02 8.7 blah blah $ awk '/abc/{a[$2,i++]=$0}END{l=asorti(a,b);for(i=1;i<=l;i++)print a[b[i]]}' *.txt abc 0.01 8.0 abc 0.02 8.3 abc 0.02 8.7 abc 0.06 9.4 abc 0.2 9.0 
asorti() is a GNU awk extension; since the question is tagged Linux, this is not a major issue. (2) The assignment a[$2] = $0 means that you are only saving unique values from the second column, not all lines that match.
a[$2], fixed.First problem: you've used -t_ to specify the field separator, but the output doesn't contain _ characters.
Next problem: the -k option has two arguments, start field and end field. By omitting the end field, you get end_of_line by default.
I'd suggest writing it like this:
grep "abc" *.txt | sort -nr -k2,2 
-k2 as a shorthand for -k2,2. The man page says: _ -k, --key=POS1[,POS2] start a key at POS1, end it at POS2 (origin 1)_.
sort -t : -k 2,2n -k 5.3,5.4 here: gnu.org/software/coreutils/manual/coreutils#sort-invocation