sorting by different columns in a sequence or sorting by multiple columns at once

Logan Lee

12/8/22, 6:32 AM

What is the difference between sort -t' ' -k1,1n -k2,2n and sort -t' ' -k1,2n?

Could you give examples?

I've tried:

logan@logan-mainPC:~/my-test/learn-sort$ cat myage 
my age 1
my age 100
my age 2
my age 200
logan@logan-mainPC:~/my-test/learn-sort$ cat myage | sort -k2,3
my age 1
my age 100
my age 2
my age 200
logan@logan-mainPC:~/my-test/learn-sort$ cat myage | sort -k2,2 -k3,3
my age 1
my age 100
my age 2
my age 200
logan@logan-mainPC:~/my-test/learn-sort$ cat myage | sort -k2,2 -k3,3n
my age 1
my age 2
my age 100
my age 200

I think sort -k2,3 sorts 'age 1', 'age 100', ... and sort -k2,2 -k3,3 sorts 'age', 'age',... then '1', '100', .... Since they all treat columns as strings they produce the same outcome.

But sort -k2,2 -k3,3n produces different outcome because it treats column 3 as numbers.

But then:

logan@logan-mainPC:~/my-test/learn-sort$ cat myage | sort -k2,3n
my age 1
my age 100
my age 2
my age 200

which is strange. Found out the reason is because column 2 is not numbers.

logan@logan-mainPC:~/my-test/learn-sort$ cat myage | sort --debug -k2,3n
sort: using ‘en_AU.UTF-8’ sorting rules
sort: key 1 is numeric and spans multiple fields
my age 1
   ^ no match for key
________
my age 100
   ^ no match for key
__________
my age 2
   ^ no match for key
________
my age 200
   ^ no match for key
__________

Thanks.

1 + 2

sort

24601

12/8/22, 6:36 AM

read [ask] then [edit] your question accordingly with details of the research you have done to find an answer.

Logan Lee

12/8/22, 6:57 AM

@24601 yep i edited the question thx!

Score:0

Ubuntu

Logan Lee

12/8/22, 7:21 AM

I can see what is happening by --debug flag.

sort -k2,3 indeed sorts 'age 1', 'age 100',...

logan@logan-mainPC:~/my-test/learn-sort$ cat myage | sort --debug -t' ' -k2,3
sort: using ‘en_AU.UTF-8’ sorting rules
my age 1
   _____
________
my age 100
   _______
__________
my age 2
   _____
________
my age 200
   _______
__________

sort -k2,2 -k3,3 sorts by 'age',... then '1', '100', ...

logan@logan-mainPC:~/my-test/learn-sort$ cat myage | sort --debug -t' ' -k2,2 -k3,3
sort: using ‘en_AU.UTF-8’ sorting rules
my age 1
   ___
       _
________
my age 100
   ___
       ___
__________
my age 2
   ___
       _
________
my age 200
   ___
       ___
__________

Lastly

logan@logan-mainPC:~/my-test/learn-sort$ cat myage | sort --debug -t' ' -k2,2 -k3,3n
sort: using ‘en_AU.UTF-8’ sorting rules
my age 1
   ___
       _
________
my age 2
   ___
       _
________
my age 100
   ___
       ___
__________
my age 200
   ___
       ___
__________

treats third column as numbers.

0 + 0

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: sorting by different columns in a sequence or sorting by multiple columns at once

TH: เรียงตามคอลัมน์ต่างๆ ตามลำดับ หรือเรียงตามหลายคอลัมน์พร้อมกัน

RO: sortarea după coloane diferite într-o secvență sau sortarea după mai multe coloane simultan

RU: сортировка по разным столбцам в последовательности или сортировка по нескольким столбцам сразу

VI: sắp xếp theo các cột khác nhau trong một trình tự hoặc sắp xếp theo nhiều cột cùng một lúc

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