On 11/15/2010 11:24 AM, Stefan Berger wrote:
I tried this now and converted all \\ to \. I still get the same
problem
here with dash using 'read -r line' now. The same problem exists with
echo "\1"
or
echo '\1'
Ah - the plot thickens, and the light bulb goes on for me. It's not
just a problem with read, but also with your use of 'echo' to try and
replay a just-read string. 'echo' and '\' don't mix. You have to
use
printf for any chance of portability.
printf %s\\n "\1"
printf %s\\n '\1'
run via bash or dash. Bash prints out '\1' and dash (0.5.6-2.fc14)
prints char(1) in both cases.
Yes, because dash's echo is POSIX-compliant by default, and bash's is
(intentionally) not. 'shopt -s xpg_echo' in bash to get bash behaving
more like POSIX in automatically interpolating \, although you'll still
get a difference in whether \1 gets interpolated to char(1), since POSIX
only requires interpolation of \0nnn (dash's interpolation of \1 is an
extension):
$ dash -c "echo '"'\1'\' | od -tx1
0000000 01 0a
0000002
$ shopt -s xpg_echo
$ echo '\1'
\1
$ echo '\041'
!
$ shopt -u xpg_echo
$ echo '\041'
\041
ke@office (0) ~/libvirt
$ dash -c "echo '"'\041'\'
!
$ dash -c 'printf %s\\n "\\041"'
\041
--
Eric Blake eblake(a)redhat.com +1-801-349-2682
Libvirt virtualization library
http://libvirt.org