command sort

info

1. sort sorts the contents of a text file, line by line

2. rules

   1. number before letter

   2. alphabet

   3. lowercase before uppercase

demo

1. simple sort

   1. test data

       $ cat data.txt
       apples
       oranges
       pears
       kiwis
       bananas
      

   2. sort lines in this file alphabetically

       $ sort data.txt
      

   3. redirect output

       $ sort data.txt > output.txt
      
       # same as
       $ sort -o output.txt data.txt
      

   4. sorting in reverse order

       # using `-r` flag
       $ sort -r data.txt
      

2. handling mixed-case data

   1. test data

       $ cat data.txt
       a
       b
       A
       B
       b
       c
       D
       d
       C
      

   2. simple sort

       $ sort data.txt
       a
       A
       b
       b
       B
       c
       C
       d
       D
      

   3. enforce bytewise sorting

       $ export LC_ALL=C
       $ sort data.txt
       A
       B
       C
       D
       a
       b
       b
       c
       d
      
       # performing a `case-insensitive bytewise` sort
       $ sort -f data.txt
       A
       a
       B
       b
       b
       C
       c
       D
       d
      

3. checking for sorted order

        $ sort -c data.txt
   

4. sorting multiple files using the output of find

        $ find . -name "data?.txt" -print0 | sort --files0-from=-
   

5. comparing only selected fields of data

   1. based on names

       # 1. test data
       $ cat data.txt
       01 Joe
       02 Marie
       03 Albert
       04 Dave
      
       # 2. simple sort
       $ sort data.txt
       01 Joe
       02 Marie
       03 Albert
       04 Dave
      
       # 3. `k` stands for `key`
       # -k pos1,pos2
       $ sort -k 2 data.txt
      

   2. ignore and specify where to stop

       # 1. test data
       $ cat data.txt
       01 Joe Sr.Designer
       02 Marie Jr.Developer
       03 Albert Jr.Designer
       04 Dave Sr.Developer
      
       # 2. sort by field 3
       $ sort -k 3 data.txt
       03 Albert Jr.Designer
       02 Marie Jr.Developer
       01 Joe Sr.Designer
       04 Dave Sr.Developer
      
       # 3. ignore the first three characters of the third field
       $ sort -k 3.3 data.txt
       01 Joe Sr.Designer
       03 Albert Jr.Designer
       02 Marie Jr.Developer
       04 Dave Sr.Developer
      
       # 4. sort based on only the third-through-fifth characters of the third field
       $ sort -k 3.3,3.5 data.txt
      

6. using sort and join together

   1. test data

       $ cat file1.txt
       3       tomato
       1       onion
       4       beet
       2       pepper
      
       $ cat file2.txt
       4       orange
       3       apple
       1       mango
       2       grapefruit
      

   2. sort these two files and join them

       $ join <(sort file1.txt) <(sort file2.txt)
       1 onion mango
       2 pepper grapefruit
       3 tomato apple
       4 beet orange
      

7. sort with tab delimiter

   1. ansi-c quoting

       # words of the form `$'string'` are treated specially
       # so `$'\t'` is `horizontal tab`
       $ sort -t$'\t' -k3 -nr data.txt