Linux sort Command

In Linux we can use “sort” command to sort lines of text files.

Sort command takes blank space as field separator and entire Input file as sort key.

Note: sort command doesn’t sort the source files but only print the sorted output to terminal, until your redirect the output to new file.

sort command Syntax

>> sort [OPTION]... [FILE]...

Set up fruits.txt file to Understand sort Command

Let’s create a file first that we will use to understand sort Command.

Create a file fruits.txt using echo command.

>> echo -e "Kiwi\nMango\nDate\nApple\nCherry\nBanana\nAppricot\nWaterMelon"

sort Command Example

Now, use sort Command to sort the fruits.txt file content.

~$ sort fruits.txt

By default, sort command just output the content into the terminal not in the actual file.

Sort the contents of the file ‘fruits.txt’ and write it to a file called (fruits_sorted.txt). Also, verify the new sorted file content by using cat command.

sort Command Output Sorted Content another File

~$ sort fruits.txt > fruits_sorted.txt

~$  cat fruits_sorted.txt

sort -r Command Sort in Reverse Order

~$ sort  -r fruits.txt

sort -nk2 Command Sort by 2nd Column

Let’s create a new file by using ls -l and output the content to list1.txt

~$  ls -l > list1.txt

~$  cat list1.txt

~$  sort -nk2 lsl.txt

sort -nk7 Command Sort by 7th Column

~$  sort -nk7 lsl.txt

sort -k Command Sort by 9th Non-numeric Column

~$  sort -k6 list1.txt

sort -u Command Remove Duplicate Content

~$  sort -u fruits.txt

sort -f Command Case Incensitive Sort

~$  sort -f fruits.txt

sort Multiple files

Let create one more file list2.txt and put outout of ls -al to learn sort multiple files.

~$  ls -al > list2.txt

~$  cat list2.txt

~$  sort list1.txt list2.txt

~$  sort -u list1.txt list2.txt

~$  sort -ur list1.txt list2.txt

sort Command Pipe with another Command

~$  ls -l /home/$USER | sort -k9

Sort Based on More than One Field

~$ $ ls -l /home/$USER | sort -t "," -nk7 -k6

sort Command in Linux (Documentation)

~$ man sort

NAME
       sort - sort lines of text files

SYNOPSIS
       sort [OPTION]... [FILE]...
       sort [OPTION]... --files0-from=F

DESCRIPTION
       Write sorted concatenation of all FILE(s) to standard output.

       With no FILE, or when FILE is -, read standard input.

       Mandatory  arguments  to long options are mandatory for short options
       too.  Ordering options:

       -b, --ignore-leading-blanks
              ignore leading blanks

       -d, --dictionary-order
              consider only blanks and alphanumeric characters

       -f, --ignore-case
              fold lower case to upper case characters

       -g, --general-numeric-sort
              compare according to general numerical value

       -i, --ignore-nonprinting
              consider only printable characters

       -M, --month-sort
              compare (unknown) < 'JAN' < ... < 'DEC'
a
       -h, --human-numeric-sort
              compare human readable numbers (e.g., 2K 1G)

       -n, --numeric-sort
              compare according to string numerical value

       -R, --random-sort
              shuffle, but group identical keys.  See shuf(1)

       --random-source=FILE
              get random bytes from FILE

       -r, --reverse
              reverse the result of comparisons

       --sort=WORD
              sort according to WORD: general-numeric -g, human-numeric  -h,
              month -M, numeric -n, random -R, version -V

       -V, --version-sort
              natural sort of (version) numbers within text

       Other options:

       --batch-size=NMERGE
              merge at most NMERGE inputs at once; for more use temp files

       -c, --check, --check=diagnose-first
              check for sorted input; do not sort

       -C, --check=quiet, --check=silent
              like -c, but do not report first bad line

       --compress-program=PROG
              compress temporaries with PROG; decompress them with PROG -d

       --debug
              annotate  the  part  of  the line used to sort, and warn about
              questionable usage to stderr

       --files0-from=F
              read input from the files specified by NUL-terminated names in
              file F; If F is - then read names from standard input
       
       -k, --key=KEYDEF
              sort via a key; KEYDEF gives location and type

       -m, --merge
              merge already sorted files; do not sort

       -o, --output=FILE
              write result to FILE instead of standard output

       -s, --stable
              stabilize sort by disabling last-resort comparison

       -S, --buffer-size=SIZE
              use SIZE for main memory buffer

       -t, --field-separator=SEP
              use SEP instead of non-blank to blank transition

       -T, --temporary-directory=DIR
              use DIR for temporaries, not $TMPDIR or /tmp; multiple options
              specify multiple directories

       --parallel=N
              change the number of sorts run concurrently to N

       -u, --unique
            with -c, check for strict ordering; without  -c,  output  only
              the first of an equal run

       -z, --zero-terminated
              line delimiter is NUL, not newline

       --help display this help and exit

       --version
              output version information and exit