sort

Show the sorted version of file

sort test.txt

Show the sorted version of file in the reverse order

sort -r test.txt

Show the sorted version of file according to 2nd column (n is used if column contains numerical values)

sort -nk2 test.txt

Show the sorted version of file according to 3rd column (no numerical value in column 3)

sort -k3 test.txt

Use sort command with a pipeline (without any file)

ls -lah | sort -nk2

Sort the lines and remove duplicates (again this is just showing, not changing any content)

sort -u test.txt

Sort the contents of 2 files and concetenate the output

sort file1.txt file2.txt

Sort the contents of 2 files and concetenate the output, then remove the duplicates

sort -u file1.txt file2.txt

Credit

https://github.com/areyou1or0/Bash-Fu/blob/master/sort