Padded printf format strings not adding enough padding with multi-byte characters - bash

Question

I often use printf inside shell scripts to make some nice aligned outputs
The problem is, everytime there is an accent (éèà) in the printed string, it shifts the following string 1 step back.
Example :
printf "%-10s %s\n" "toto" "test"
printf "%-10s %s\n" "titi" "test"
printf "%-10s %s\n" "tété" "test"
printf "%-10s %s\n" "toto" "test"
Expected :
toto test
titi test
tété test
toto test
Got :
toto test
titi test
tété test
toto test
Does someone have an explanation on this and what can I do to make printf doing it right with special characters?
Thank you for your help

Answer 1

Does someone have an explanation on this
é is character encoded with two bytes.
what can I do to make printf doing it right with special characters?
Design your own method of padding that would take into account utf-8s. Ideally I believe a tool like wprintf or making %Ls format specifier call wcwidth() to determine character width or something similar would be welcomed and usefull.
As of now at least my bash when calculating string length takes utf-8 chars into account. You could insert the padding yourself:
printf "%-10s %s\n" "titi" "test";
s="tété";
# (echo -n "$s" | wc -c) is 6 , but ${#s} is 4!
printf "%s%*s %s\n" "$s" "$((10-${#s}))" "" "test"

Answer 2

Adapted my answer from https://unix.stackexchange.com/a/592479/310674
#!/usr/bin/env bash
align_left(){ printf %s%\*s "${2:0:$1}" $(($1-${#2})) '';}
printf '%s %s\n' \
"$(align_left 10 "toto")" "test" \
"$(align_left 10 "titi")" "test" \
"$(align_left 10 "tété")" "test" \
"$(align_left 10 "têtu")" "test"
Output:
toto test
titi test
tété test
têtu test

Answer 3

But you can use other tool to print your report in that manner. Following example uses awk:
echo "toto" | awk '{printf "%-10s test\n", $1}'
echo "tété" | awk '{printf "%-10s test\n", $1}'
echo "titi" | awk '{printf "%-10s test\n", $1}'
EDIT:
The following statement was partially wrong:
printf might not be part of bash, but coreutils. Coreutils have a long history with multibyte characters - https://crashcourse.housegordon.org/coreutils-multibyte-support.html.
As noted in a comment by #charles-duffy - printf, in this case, is shell builtin. You can check it with:
[Alex#NormandySR2 ~]$ type printf
printf is a shell builtin
I also agree with the fact that most shell implements their own printf. I checked the following:
fish
bash
zsh
tcsh
ksh
dash
oil
All of them uses printf builtin that can differ in details. So my assumption about printf as part of coreutils, in this case, was wrong.