sort
sort [OPTION]... [FILE]...
Examples
To sort in numeric order, you must pass the -n flag, or you get unexpected results
$ head -10 aliens_release.txt | sort 10|Spain|27 October 1986| 1|Canada|18 July 1986| 2|USA|18 July 1986| 3|Japan|09 August 1986| 4|Brazil|28 August 1986| 5|UK|29 August 1986| 6|Argentina|11 September 1986| 7|Italy|30 September 1986| 8|Sweden|03 October 1986| 9|France|08 October 1986| $ head -10 aliens_release.txt | sort -n 10|Spain|27 October 1986| 1|Canada|18 July 1986| 2|USA|18 July 1986| 3|Japan|09 August 1986| 4|Brazil|28 August 1986| 5|UK|29 August 1986| 6|Argentina|11 September 1986| 7|Italy|30 September 1986| 8|Sweden|03 October 1986| 9|France|08 October 1986|
Sort a directory based on size
ls -s | sort -n
Setting the field separator to TAB and sorting the second column
head -5 aliens_release.txt | sort -t'|' -k2 4|Brazil|28 August 1986| 1|Canada|18 July 1986| 3|Japan|09 August 1986| 5|UK|29 August 1986| 2|USA|18 July 1986|
Get a list of distinct users logged into a system
who | nawk '{print $1}' | sort | uniq