shellscript iterate through letters

Question

I need to iterate from c to k alphabetically in shellscript, the attempt below failed, how do I do it properly?

for((i='c';i<'k';i++))
do
  echo $i
done

score 2 · Answer 1 · answered May 14 '11 at 03:47

2

This will work in bash at least:

for i in {c..k}

answered May 14 '11 at 03:47

John Zwinck

Is there a way to do this in shell (not bash)? – Jakub P Jun 14 '17 at 10:17
@JakubP: What is "shell (not bash)"? Korn shell? Zsh? Fish? Dash? – John Zwinck Jun 20 '17 at 03:31
I mean shell as sh. it's always a problem to search for shell scripts, as I haven't found any specific name for it such as bash, ksh, zsh - those are unique. And when one types shell, then it's confusing :-) – Jakub P Jun 28 '17 at 18:38
@JakubP: There is no "sh." There are implementations like the ones I listed. `sh` is not a specific thing, but rather a cluster of related things. – John Zwinck Jun 29 '17 at 01:52

score 2 · Accepted Answer · edited May 15 '11 at 16:28

2

this one works in my shell (Bash 3.0+):

for c in {c..k}
do
  echo $c
done

edited May 15 '11 at 16:28

John Zwinck

answered May 14 '11 at 03:49

LeleDumbo

This goes from {a..z} whereas the question asked for {c..k}. – John Zwinck May 14 '11 at 03:57
yeah, I know. just change to c..k – LeleDumbo May 15 '11 at 16:06
I wonder why my correct answer which was posted earlier didn't get accepted. Oh well. I've edited your answer for you. – John Zwinck May 15 '11 at 16:28
Is there a way to do this in shell (not bash)? – Jakub P Jun 14 '17 at 10:17

score 1 · Answer 3 · answered May 15 '11 at 19:10

Given that you are not asking for bashisms specifically, here are some alternatives without them.

Simple:

for c in c d e f g h i j k; do
    echo $c
done

Avoiding the need to list all the characters:

s=$(printf %d "'c")
e=$(printf %d "'k")
i=$s
while [ $i -le $e ]; do
    c=$(printf \\$(printf %o $i))
    echo $c
    i=$((i+1))
done

3 Answers3