rearrange columns using awk or cut command - awk

Question

I have large file with 1000 columns. I want to rearrange so that last column should be the 3rd column. FOr this i have used,
cut -f1-2,1000,3- file > out.txt
But this does not change the order.
Could anyone help using cut or awk?
Also, I want to rearrange columns 10 and 11 as shown below:
Example:
1 10 11 2 3 4 5 6 7 8 9 12 13 14 15 16 17 18 19 20

Answer 1

try this awk one-liner:
awk '{$3=$NF OFS $3;$NF=""}7' file
this is moving the last col to the 3rd col. if you have 1000, then it does it with 1000th col.
EDIT
if the file is tab-delimited, you could try:
awk -F'\t' -v OFS="\t" '{$3=$NF OFS $3;$NF=""}7' file
EDIT2
add an example:
kent$ seq 20|paste -s -d'\t'
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
kent$ seq 20|paste -s -d'\t'|awk -F'\t' -v OFS="\t" '{$3=$NF OFS $3;$NF=""}7'
1 2 20 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
EDIT3
You didn't give any input example. so assume you don't have empty columns in original file. (no continuous multi-tabs):
kent$ seq 20|paste -s -d'\t'|awk -F'\t' -v OFS="\t" '{$3=$10 FS $11 FS $3;$10=$11="";gsub(/\t+/,"\t")}7'
1 2 10 11 3 4 5 6 7 8 9 12 13 14 15 16 17 18 19 20
After all we could print those fields in a loop.

Answer 2

I THINK what you want is:
awk 'BEGIN{FS=OFS="\t"} {$3=$NF OFS $3; sub(OFS "[^" OFS "]*$","")}1' file
This might also work for you depending on your awk version:
awk 'BEGIN{FS=OFS="\t"} {$3=$NF OFS $3; NF--}1' file
Without the part after the semi-colon you'll have trailing tabs in your output.

Answer 3

Since many people are searching for this and even the best awk solution is not really pretty and easy to use I wanted to post my solution (mycut) written in Python:
#!/usr/bin/env python3
import sys
from signal import signal, SIGPIPE, SIG_DFL
signal(SIGPIPE,SIG_DFL)
#example usage: cat file | mycut 3 2 1
columns = [int(x) for x in sys.argv[1:]]
delimiter = "\t"
for line in sys.stdin:
parts = line.split(delimiter)
print("\t".join([parts[col] for col in columns]))
I think about adding the other features of cut like changing the delimiter and a feature to use a * to print the remaning columns. But then it will get an own page.

Answer 4

A shell wrapper function for awk' that uses simpler syntax:
# Usage: rearrange int_n [int_o int_p ... ] < file
rearrange ()
{
unset n;
n="{ print ";
while [ "$1" ]; do
n="$n\$$1\" \" ";
shift;
done;
n="$n }";
awk "$n" | grep '\w'
}
Examples...
echo foo bar baz | rearrange 2 3 1
bar baz foo
Using bash brace expansion, rearrange first and last 5 items in descending order:
echo {1..1000}a | tr '\n' ' ' | rearrange {1000..995} {5..1}
1000a 999a 998a 997a 996a 995a 5a 4a 3a 2a 1a
Sorted 3-letter shells in /bin:
ls -lLSr /bin/?sh | rearrange 5 9
150792 /bin/csh
154072 /bin/ash
771552 /bin/zsh
1554072 /bin/ksh