Re: incorrect character handling

[Greg Wooledge]

On Wed, Mar 31, 2021 at 02:31:46AM +0700, by.sm--- via Bug reports for the GNU 
Bourne Again SHell wrote:
> poc=whoami
> $poc
> python3 -c "print('!!')"
> 
> That return 'whoami' command. 

You're running into the csh-style history expansion.  A lot of us simply
disable it, because it's not worth the effort it takes to work around it.

set +o histexpand


If you insist on keeping it, and working around it, the key is to
understand that single quotes will protect you, but double quotes may
not.

echo 'hi!'

echo "hi!"


The actual behavior of ! (history expansions) inside double quotes has
changed across bash versions, so you may have more problems, or fewer
problems, depending on your bash version.  But there will never be
zero problems.