sort Command in Unix

The sort command sorts a file according to fields--the individual pieces of data on eachline. Sorting priority is number, upper-case, lower-case and symbol.

By default, sort assumes that the fields are just words separated by blanks

Syntax : sort <flags> <sort fields> <file name>
The most common flags are as follows:

Options	Descriptions
-n	Sort numerically, Ignore blanks and tabs
-r	Reverse the order of sort
-f	Sort upper and lowercase together
+x	Ignore first x fields when sorting

Specify the sort keys like this:

+m   Start at the first character of the m+1th field.
-n     end at the last character of the nth field (if -N omitted, assume the end of the line).
-t      delimeter keys
-k1,2 field1 in primary key,filed2 is secondary key

Examples :

File name : example_sort.dat


g hi 123 liead
a bc 987 asd
d ef 873 lpoae
m no 873 apoie
j kl 234 ppoasd

sort the file ascending order

$ sort example_sort.dat

a bc 987 asd

d ef 873 lpoae

g hi 123 liead

j kl 234 ppoasd

m no 873 apoie

numeric sort the file using field3

$ sort -n -k3 example_sort.dat
g hi 123 liead
j kl 234 ppoasd
d ef 873 lpoae
m no 873 apoie
a bc 987 asd

tab delimiter [ctrl+v+TAB] sort the file using field2

$ sort -t"      " -k2 example_sort.dat
a bc 987 asd
d ef 873 lpoae
g hi 123 liead
j kl 234 ppoasd
m no 873 apoie

reverse sort

$ sort -r  example_sort.dat
m no 873 apoie
j kl 234 ppoasd
g hi 123 liead
d ef 873 lpoae
a bc 987 asd

sorted datas stored into another file

$ sort  example_sort.dat > example.sorted

$ cat example.sorted
a bc 987 asd
d ef 873 lpoae
g hi 123 liead
j kl 234 ppoasd
m no 873 apoie

cut field3 and apply numeric sort

$ cut -d"       " -f3 example_sort.dat |sort -n
123
234
873
873
987

cut field3 and apply numeric sort & eliminate duplicate values

$ cut -d"       " -f3 example_sort.dat |sort -n|uniq -u
123
234
873
987