Bash Using sort Sort by keys
Example
Suppose we have this file:
test>>cat Hogwarts
Harry Malfoy Rowena Helga
Gryffindor Slytherin Ravenclaw Hufflepuff
Hermione Goyle Lockhart Tonks
Ron Snape Olivander Newt
Ron Goyle Flitwick Sprout
To sort this file using a column as key use the k option:
test>>sort -k 2 Hogwarts
This will sort the file with column 2 as the key:
Ron Goyle Flitwick Sprout
Hermione Goyle Lockhart Tonks
Harry Malfoy Rowena Helga
Gryffindor Slytherin Ravenclaw Hufflepuff
Ron Snape Olivander Newt
Now if we have to sort the file with a secondary key along with the primary key use:
sort -k 2,2 -k 1,1 Hogwarts
This will first sort the file with column 2 as primary key, and then sort the file with column 1 as secondary key:
Hermione Goyle Lockhart Tonks
Ron Goyle Flitwick Sprout
Harry Malfoy Rowena Helga
Gryffindor Slytherin Ravenclaw Hufflepuff
Ron Snape Olivander Newt
If we need to sort a file with more than 1 key , then for every -k option we need to specify where the sort ends. So -k1,1 means start the sort at the first column and end sort at first column.
-t option
In the previous example the file had the default delimeter - tab. In case of sorting a file that has non-default delimeter we need the -t option to specify the delimeter. Suppose we have the file as below:
test>>cat file
5.|Gryffindor
4.|Hogwarts
2.|Harry
3.|Dumbledore
1.|The sorting hat
To sort this file as per the second column, use:
test>>sort -t "|" -k 2 file
This will sort the file as below:
3.|Dumbledore
5.|Gryffindor
2.|Harry
4.|Hogwarts
1.|The sorting hat
