Orders columns of a file from a given list of column names.
This script is designed to work on large files and has been tested with 5M rows and 100 columns (~ 2 minutes).
sh ordercols.sh list_file input_file [Separator]A B C D E
This is the order you want to get from your input file.
C D B E A
1 2 3 4 5
This is the input file that you want to sort. The column names must match those in the list file.
sh ordercols.sh list1.txt input1.txt
Here, we don't need to specify the separator, as the default one is "\t".
A B C D E
5 3 1 2 4
By default the separator is "\t".
But you can specify your own separator, like this :
sh ordercols.sh list2.txt input2.txt ";"
Basically, we are constructing an awk command from several tools in the shell.
This command is then sent to a file and executed.
If you look at the code, you'll see that's it's a bunch of tricks and not elegant. But it works.
I'm opened to suggestions !