user command changes prompt

[jeanconn]

I just suggested that Takashi do something like this:

ascdsenv = getenv('source /home/ascds/.ascrc -r release; set prompt="Tcsh-%P- "', shell='tcsh')

because he has a .ascrcuser that customizes the prompt for the ASCDS environment. Should something like getenv add a "set prompt" after every command to guarantee the user can't change the prompt and get stuck?

[taldcroft]

(bored in hotel room) iirc getenv makes a dict of env vars to set. So we
could blacklist certain ones like prompt? Can you include a minimal
example that shows the problem just by setting the prompt in getenv?
On Jul 23, 2013 5:54 PM, "Jean Connelly" notifications@github.com wrote:

I just suggested that Takashi do something like this:

ascdsenv = getenv('source /home/ascds/.ascrc -r release; set
prompt="Tcsh-%P- "', shell='tcsh')

because he has a .ascrcuser that customizes the prompt for the ASCDS
environment. Should something like getenv add a "set prompt" after every
command to guarantee the user can't change the prompt and get stuck?

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/3
.

[jeanconn]

The problem is that you just get a hang if you change the prompt away from
the pexpect expected return type of "Tcsh-%P- "'. So getenv wouldn't
process that dictionary until pexpect timeout at 1e8 seconds. Right?

This, expectedly, hangs

env = getenv('set prompt="tom"', shell='tcsh')

This works.

env = getenv('set prompt="tom"; set prompt="Tcsh-%P- "', shell='tcsh')

[jeanconn]

It looks like this sort of becomes a problem by default when working in a conda env.

For example, I wanted to run the agasc module tests. I'm in a little environment that got its prompt rewritten by default

(agascv1) bash-4.1$ 

Now this looks fine when I use Ska.Shell.bash

In [1]: import Ska.Shell
In [2]: Ska.Shell.bash("which bash")
Out[2]: ['/bin/bash']

But if I try to use the ascds environment it hangs

In [3]: ascds_env = Ska.Shell.getenv('source {} -r release'.format('/home/jeanconn/.ascrc'), shell='tcsh')
In [5]: ascds_env['PS1']
Out[5]: '(agascv1) \\s-\\v\\$'
In [6]: Ska.Shell.bash("which bash", env=ascds_env) 
(trust me, it hangs)

In [11]: del ascds_env['PS1']
In [12]: Ska.Shell.bash("which bash", env=ascds_env)
Out[12]: ['/bin/bash']

I think, then, that we should either ignore PS1 in the supplied env or some other fix in Ska.Shell instead of fixing this in any module that might make and use an environment (granted, there aren't that many of those anyway).

[jeanconn]

Or maybe, like /usr/bin/python -E there's a convenient option to bash to have it ignore vars like PS1.