seq

seq is used to produce a sequence of numbers 

$ seq 3
1
2
3

Useful Options / Examples

seq -s [SEPERATOR] 

$ seq -s " " 3
1 2 3
$ seq -s " | " 3
1 | 2 | 3
  • -s is the seperator between the numbers. For the default the seperator is equal to ‘\n’, the end of line character. Takes in a string value.

seq -f [FORMAT] 

$ seq -f "01/%02g/2016" 3
01/01/2016
01/02/2016
01/02/2016
  • -f Sets a format for the sequence. In this case, a date like format was chosen.

seq [FIRST] [LAST]

$ seq 5 10
5
6
7
8
9
10
  • Putting in two number arguments prints a list of numbers starting from the first number to the second number

seq [FIRST] [INCREMENT] [LAST]

$ seq 2 2 10
2
4
6
8
10
  • The FIRST argument is where the sequence will start.
  • The INCREMENT argument determines how the sequence increments by.
  • The LAST argument is where the sequence will end.

Bash Script

Input
> for i in $(seq 3)
> do
>   echo "i is now $i"
> done
Output
i is now 1
i is now 2
i is now 3
  • In a for loop seq can be used to increment the incrementer value.