sorting a strange file

[Gribouillis]

I suggest a 3 steps procedure

Step 1: A python program reads the big.txt file line by line and creates a new big file bigggg.txt by replacing each line

Output:
foo/bar/baz   spam/eggs  ham/bacon

with

Output:
bacon foo/bar/baz spam/eggs ham/bacon|   .  |

Notice that the primary key has been added in front of each line and the white space between tokens has been normalized to a single space. At the end of the line, the initial blocks of white space have been written, separated by dots and enclosed between pipe characters.

Step 2 Run gnu sort on bigggg.txt, producing sbigggg.txt

Step 3 Read sbigggg.txt line by line and write sbig.txt by the reverse operation on each line.