Linux Pocket Guide, 2nd Edition

Name

seq — stdin  stdout  - file  -- opt  --help  --version

Synopsis

seq [options] specification

The seq command prints a sequence of integers or real numbers, suitable for piping to other programs. There are three kinds of specification arguments:

A single number: an upper limit

seq begins at 1 and counts up to the number.

$ seq 3
1
2
3

Two numbers: lower and upper limit

seq begins at the first number and counts as far as it can without passing the second number.

$ seq 2 5
2
3
4
5

Three numbers: lower limit, increment, and upper limit

seq begins at the first number, increments by the second number, and stops at (or before) the third number.

$ seq 1 .3 2
1
1.3
1.6
1.9

You can also go backward with a negative increment:

$ seq 5 -1 2
5
4
3
2

Useful options

-w	Print leading zeroes, as necessary, to give all lines the same width: $ seq -w 8 10 08 09 10
-f format	Format the output lines with a printf-like format string, which must include either %g (the default), %e, or %f: $ seq -f '**%g**' 3 **1** **2** **3**
-s string	Use the given string as a separator between the numbers. By default, a newline is printed (i.e., one number per line): $ seq -s ':' 10 1:2:3:4:5:6:7:8:9:10