On 23/03/2020 08:20, n8dandy wrote:
Good morning,
Few days ago, I noticed something strange with dash and IFS. It was
verified with the following versions :
- 0.5.10.2 on Voidlinux
- 0.5.10.2 on Debian Buster
- 0.5.8 on Ubuntu 18.04.2 LTS (Bionic Beaver)
Here the issue :
$ ls
file.sign file1 file2 other.sign whileifs*
$ cat whileifs
#!/bin/dash
find . -type f | sort -d | while IFS=$'\n' read -r F; do
printf "%s\n" "$F"
done
This isn't about IFS, this is just because dash does not support the use
of $'\n' to indicate a newline. In dash, $'\n' is equivalent to '$\n'
(in the same way that x'y' is equivalent to 'xy' in all shells). To
portably get a string consisting of a single newline, either put a
literal newline in your source:
nl='
'
or use command substitutions:
nl=$(printf '\n.'); nl=${nl%.}
Currently, $'...' is not part of POSIX (although it has been accepted
for the next version), and dash tends not to add new features that are
not part of the standard.
Cheers,
Harald van Dijk
