Why must I enter "\\\0" to create a string "\0" in zsh?
> echo 0
0
> echo
0
slu@dev:~
> echo
slu@dev:~
> echo " "
# <--- What!!?
slu@dev:~
> echo
slu@dev:~
> echo " "
slu@dev:~
> bash
Executing .bashrc
$ echo " "
$ echo " "
$ echo " "
I gotta say, bash's behavior makes a lot more sense to me.
More details:
slu@dev:~
> echo "0" | hexdump -C
00000000 30 0a |0.|
00000002
slu@dev:~
> echo " " | hexdump -C
00000000 00 0a |..|
00000002
slu@dev:~
> echo " " | hexdump -C
00000000 00 0a |..|
00000002
slu@dev:~
> echo " " | hexdump -C
00000000 5c 30 0a | .|
00000003
slu@dev:~
> echo "\0" | hexdump -C
00000000 5c 30 0a | .|
00000003
slu@dev:~
> echo "\ " | hexdump -C
00000000 5c 00 0a |..|
00000003
slu@dev:~
> echo "\ " | hexdump -C
00000000 5c 00 0a |..|
00000003
slu@dev:~
> echo "\ " | hexdump -C
00000000 5c 5c 30 0a | .|
00000004
The biggest issue is that there is no value that produces the desired result on both bash and zsh.
Update:
slu@dev:~
> echo '0' | hexdump -C
00000000 30 0a |0.|
00000002
slu@dev:~
> echo '' | hexdump -C
00000000 5c 0a |.|
00000002
slu@dev:~
> echo '' | hexdump -C
00000000 5c 0a |.|
00000002
slu@dev:~
> echo | hexdump -C
00000000 5c 0a |.|
00000002
slu@dev:~
> echo ' ' | hexdump -C
00000000 5c 30 0a | .|
00000003
Looks like using single quotes helps get consistent behavior. I'd love for somebody to explain the behavior with the double-quotes.
Use single quotes and turn off escape handling in echo with the -E flag.
echo -E ' ' should produce a on both zsh and bash (and dash).
This is the standard (read portable) way to do it:
printf " "
Should work whatever the (Unix like) OS, whatever the shell.
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