How can I perform the equivalent of
M-x sort-columns with a stable sort?
For example, let's say my text is:
a 99 b 98 b 97 a 96 a 95 b 94 a 93 b 92 c 91 ...
And I want to perform a stable sort against the first column.
With sort-columns I would put mark at the beginning of the buffer, put point in the last line just after the first column, and
M-x sort-columns RET.
My problem is that this sort is not stable. The output is:
a 93 a 95 a 96 a 99 b 92 b 94 b 97 b 98 c 91
Whereas I need to keep the line order for each first column:
a 99 a 96 a 95 a 93 b 98 b 97 b 94 b 92 c 91
How could I do that? Is there a hidden option in
sort-columns? Or is some Elisp necessary? I know
sort --stable could do the trick but I want a solution that works on Windows where the
sort command-line tool is absent.