Re: why would "tr --complement --squeeze-repeats ..." append the substitution char once more? ...

[debian-user@howorth.org.uk]

Albretch Mueller <lbrtchx@gmail.com> wrote:
> echo "abc123" > file.txt
> ftype=$(file --brief file.txt)
> echo "// __ \$ftype: |${ftype}|"
> ftypelen=${#ftype}
> echo "// __ \$ftypelen: |${ftypelen}|"
> 
> # removing spaces ...
> ftype2=$(echo "${ftype}" | tr --complement --squeeze-repeats
> '[A-Za-z0-9.]' '_');
> echo "// __ \$ftype2: |${ftype2}|"
> ftype2len=${#ftype2}
> echo "// __ \$ftype2len: |${ftype2len}|"
> 
> lbrtchx

Short answer. tr doesn't append anything. echo does output a linefeed
at the end of the string, unless you stop it. tr dutifully translates
that to an underscore.