Easy seq Question

Shell Programming and Scripting
1

Hi! I'm trying to do this:
1 -
2 -
3 -
4 -
5 -

I'm using seq for this:

seq 1 20 > filename.txt

How do I get the "-"? I've tried -f per man but can't get anything to work. Also, is there an easier or better way than using sequence? Thanks!

2

the seq command doesn't do anything but generate sequences. How about this?

printf "%d -\n" `seq 1 20`

which amounts to printf "%d -\n" 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

1 Like
3

After much experimenting with the -f feature I finally figured out how to trick it. It needs %.0f to make it print integers, followed by whatever string you want.

seq -f '%.0f -' 1 20

I suspect it's not really meant for that and might not work the same or reliably on other systems.

2 Likes
4

Thanks everyone! Both work great and I got a lesson in -f. :slight_smile:

------ Post updated at 05:53 PM ------

Sorry - Thanks Corona688! Didn't notice until now that both posts were from you. :slight_smile:

5

If you have two constant numbers then in bash (or ksh93 or zsh) you can do

printf "%d -\n" {1..20}
6

Just for the fun of it - no seq , no "brace expansion":

yes - | sed '=' | sed 'N; s/\n/ /' | head -20
1 -
2 -
3 -
.
.
.
19 -
20 -

or

yes | sed '=' | sed 'N; s/\ny/ -/' | head -20

or

yes | sed '=' | sed 'N; s/\ny/ -/; 40q'

EDIT: or - h�h�h� -

yes - | cat -n | head -n20
7

Not the most elegant, but for sure one of - if not "The" - most intuitive & easy to read and maintain :

 seq 1 20 | sed 's/$/ -/'