UNIX Command Line

asort is a gawk-specific extension which sorts an array. More of asort can be found here and here

Lets see some array sorting example using awk asort function.
Input file:

$ cat file
KP
AS
DN

AO
BM
SE

ZW
ER
AI

Required output: Sort records in individual paragraph (each paragraph being separated by a newline), i.e. the output required is:

AS
DN
KP

AO
BM
SE

AI
ER
ZW

Awk solution using asort:

$ awk '
BEGIN{RS=""}
{
  n=split($0,arr)
  asort(arr)
  for(i=0;i<=n;i++)
     print arr[i]
}' file

Another example using asort: Horizontal sorting of fields in a file using awk asort.

Input file:

$ cat file
435 121 1 32
87 644 12 34
323 121 111 10

Required output: Sort the records in each row in descending order. i.e. output required is:

435 121 32 1
644 87 34 12
323 121 111 10

Awk solution:

$ awk '{
  split($0,a)
  asort(a)
  for(i=NF;i>0;i--){
    printf("%s ",a[i])
  }
  print ""
}' file