shell script can't tell if in compile window

shell script can't tell if in compile window

[Dan Jacobson]

Gentlemen, in the shell originally we could check with test -t or case
$- in *i* or $TERM to tell if we are in an interactive session.

Now compile mode has messed this all up so there is no way to test
anymore.  All tests act like we are just as interactive as if we were
at a shell window. By the way, the painful "check the process tree" method
http://groups.google.com/groups?selm=jyqHa.2671%243Q7.719%40news.cpqcorp.net
still wouldn't enable a shell script to tell the difference between an
{emacs compile window} vs. {emacs shell window, non-emacs shell window}
I bet.

Hmmm, how about you powder users, does (shell-command "echo $TERM")
and (compile "echo $TERM") get real live term names like me (on debian,
no .profile stuff)?  Aren't
these usually exported when emacs encounters them?  Should TERM be
removed from compile mode's environment?

Why does (shell-command "test -t&&tty") get so far to tell me 'not a
tty'!? Wait, (shell-command "/usr/bin/test -t&&tty") doesn't get that
far, good.  Aren't they supposed to act the same?  Ok, do I send a
coreutils bug or a bash bug?? Must be a bash bug because how could
test -t && tty ever pass the first hurdle.

test -t FD vs. [FD]

[Dan Jacobson]

[remove emacs group when following up]

>> Why does (shell-command "test -t&&tty") get so far to tell me 'not a
>> tty'!?

Paul> With a single argument, test only tells you whether that arguments is
Paul> empty.  You want "test -t 0" (or 1 or 2).

$ man test
       -t [FD]
              file descriptor FD (stdout by default) is opened on a terminal
I.e. argument optional

$ help test
        -t FD          True if FD is opened on a terminal.
Not so optional with bash then.

You guys should unify them.
>> Wait, (shell-command "/usr/bin/test -t&&tty") doesn't get that
>> far, good.

Paul> Looks like /usr/bin/test is buggy.

Re: shell script can't tell if in compile window

[Dan Jacobson]

>>>>> "Paul" == Paul Jarc <prj@po.cwru.edu> writes:

Paul> Dan Jacobson <jidanni@jidanni.org> wrote:
>> case $- in *i*

Paul> Works for me.

Not in a script:
case $- in *i*)read -p Age: age;esac
OK, one must do ". ./script"

>> (shell-command "echo $TERM")

Paul> I get "dumb", which seems right.

but that's the same for both *shell* and *compile*

I want to write a script that can do
read -p Age: age
only if the user can answer it.

Re: shell script can't tell if in compile window

[Paul Jarc]

Dan Jacobson <jidanni@jidanni.org> wrote:
> I want to write a script that can do
> read -p Age: age
> only if the user can answer it.

As I said, you want "test -t 0".


paul

Re: shell script can't tell if in compile window

[Dan Jacobson]

>>>>> "P" == Paul Jarc <prj@po.cwru.edu> writes:

P> Dan Jacobson <jidanni@jidanni.org> wrote:
>> I want to write a script that can do
>> read -p Age: age
>> only if the user can answer it.

P> As I said, you want "test -t 0".

$ emacs -q -eval '(compile "test -t 0&&read -p age: age||echo cant
answer here so dont ask")'
You are giving me the wrong test then. It is still asking.
I need a test that can tell a compile window from windows that can
interact.

Re: test -t FD vs. [FD]

[Paul Eggert]

Dan Jacobson <jidanni@jidanni.org> writes:

> $ man test
>        -t [FD]
>               file descriptor FD (stdout by default) is opened on a terminal
> I.e. argument optional
> 
> $ help test
>         -t FD          True if FD is opened on a terminal.
> Not so optional with bash then.
> 
> You guys should unify them.

POSIX long ago decided that FD is not optional with test -t.  GNU
'test' conforms to POSIX in this respect.  This means GNU 'test' is
incompatible with ancient Unix 'test', but that's life in the big
city.  The original specification had an ambiguous grammar, and POSIX
removed the ambiguity by making FD required.

Reference:
http://www.opengroup.org/onlinepubs/007904975/utilities/test.html

Re: test -t FD vs. [FD]

[Paul Jarc]

Paul Eggert <eggert@CS.UCLA.EDU> wrote:
> POSIX long ago decided that FD is not optional with test -t.  GNU
> 'test' conforms to POSIX in this respect.

bash's does, but coreutils' doesn't.

$ /bin/test -t > /dev/null ; echo $?
1
$ /bin/test --version
test (GNU coreutils) 5.0
Written by FIXME: ksb and mjb.

Copyright (C) 2003 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


paul