How can I count the number of characters in a Bash variable

Question

How can I count all characters in a bash variable? For instance, if I had

"stackoverflow"

the result should be

"13"

One option is [`wc`](http://linux.about.com/library/cmd/blcmdl1_wc.htm). — Aiias, Mar 24 '13 at 07:39
**using wc and tr together** `echo stackoverflow|tr -d '\n' | wc -c` — pulkit219, Apr 28 '20 at 15:33
Take `function char-count() { echo -n "$1" | wc -c | awk '{print $1}' }`, save it in your .zshrc and use it: `char-count "hello world"` and you get **11** since `${#VAR}` is not working on macOS UNIX zsh. — shogitai, Feb 04 '21 at 00:35
@Aiias Broken link. linux.about.com redirects to www.lifewire.com — Naeio, Oct 06 '22 at 10:02

SteveP · Accepted Answer · 2018-04-18T12:32:43.370

125

Using the ${#VAR} syntax will calculate the number of characters in a variable.

edited Apr 18 '18 at 12:32

answered Mar 24 '13 at 07:43

SteveP

3

Link could die. `${#parameter}` gives the length in characters of the expanded value of parameter is substituted. If parameter is `*` or `@`, the value substituted is the number of positional parameters. If parameter is an array name subscripted by `*` or `@`, the value substituted is the number of elements in the array. If parameter is an indexed array name subscripted by a negative number, that number is interpreted as relative to one greater than the maximum index of parameter, so negative indices count back from the end of the array, and an index of -1 references the last element. – Alessandro Flati Mar 25 '20 at 08:58
Bash doesn't properly count unicode characters or other multibyte characters. – deanresin May 02 '21 at 00:15

score 88 · Answer 2 · edited Sep 03 '20 at 20:41

88

Use the wc utility with the print the byte counts (-c) option:

$ SO="stackoverflow"
$ echo -n "$SO" | wc -c
    13

You'll have to use the do not output the trailing newline (-n) option for echo. Otherwise, the newline character will also be counted.

edited Sep 03 '20 at 20:41

coolaj86

answered Mar 11 '15 at 13:21

mihai

4

You don't need echo. If going for `wc` do `wc -c <<< $SO` – jacwah Apr 02 '16 at 16:18
@jacwah: this will also count the trailing newline (so answer will be 14 and not 13). – gniourf_gniourf Nov 26 '17 at 14:07
6

Use -m for chars, not -c which is for bytes – raacer Dec 29 '18 at 01:28
2

echo adds a newline unless you use the -n flag, however not all implementations of echo support the -n flag. use printf for a more consistent result – Mr Griever Feb 01 '20 at 16:50
3

please note that using (admittedly cool) here-string solution suggested by @jacwah you end up counting one character more, because bash always adds a newline to the end of the string. – gerlos Feb 12 '20 at 11:47

score 33 · Answer 3 · edited Feb 26 '18 at 05:31

33

jcomeau@intrepid:~$ mystring="one two three four five"
jcomeau@intrepid:~$ echo "string length: ${#mystring}"
string length: 23

edited Feb 26 '18 at 05:31

kos

answered Mar 24 '13 at 07:51

Raj

1

This should be the answer – user267092 Nov 04 '15 at 16:14
This worked for me on Jenkinsfile, but without the # sign. `echo "string length: ${mystring}"` – soBusted Dec 24 '19 at 11:06
Using this I get an incorrect count. This happens when my string has colors and other format elements such as bold, background, etc. – onlycparra Dec 03 '22 at 03:38

score 17 · Answer 4 · answered Mar 24 '13 at 07:41

17

${#str_var}

where str_var is your string.

answered Mar 24 '13 at 07:41

aga

score 2 · Answer 5 · answered Oct 03 '17 at 10:18

2

you can use wc to count the number of characters in the file wc -m filename.txt. Hope that help.

answered Oct 03 '17 at 10:18

Norbert Wupona

Not really. Example echo "ok" | wc -m -> 3 – Philippe Delteil Nov 14 '18 at 14:35
2

@PhilippeDelteil, echo -n – raacer Dec 29 '18 at 01:27
1

Yes, thanks. I ve noticed that echo always includes a new line at the end and that you can remove it with -n option. – Philippe Delteil Dec 31 '18 at 20:21
3

echo can be inconsistent depending on your shell, printf is far more consistent – Mr Griever Feb 01 '20 at 16:48

5 Answers5