cd in a tcl script
Gunnar Törnblom
I expected to get the new directory listed by the
puts - line below, but instead it list my old
default directory. Why ? ("usr/test" exists and is
a directory).
set drootdir "/usr/test"
if [file exists $drootdir] {
if {[file type $drootdir] != "link"} {
cd $drootdir
puts "PWD $env(PWD)"
} else {
Gunnar Törnblom
Neil Walker
Hi
Gunnar Tornblom was asking about cd and pwd ...
I could talk about shells and processes, but I always get it wrong, so:
> tclsh
% puts "PWD in tcl = [pwd], outside = $env(PWD)"
PWD in tcl = /home/neilw, outside = /home/neilw
% cd tcl
% !p
PWD in tcl = /home/neilw/tcl, outside = /home/neilw
% exit
> pwd
/home/neilw
i.e. use the built-in pwd command!
Cheers
Neil
Jeffrey Hobbs
In article <321AC6...@senet.abb.se>,>puts - line below, but instead it list my old directory.
> puts "PWD $env(PWD)"
env(PWD) doesn't correlate with 'cd' in Tcl. Use [pwd] (the
Tcl command) instead.
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Gunnar Törnblom
OK, but what I tried to do was really to change the current working dir
of the parent process because I will execute another (non-tcl) script that
require another directory (I am building a tcl/tk interface to an existing
application that I want to avoid to modify for compatibility reasons).
I suppose that what I must do is:
set env(PWD) $drootdir
Thanks to everyone who responded,
Gunnar Törnblom
Larry W. Virden
According to Gunnar Törnblom <gunnar....@senet.abb.se>:
:OK, but what I tried to do was really to change the current working dir
:of the parent process because I will execute another (non-tcl) script that
:require another directory (I am building a tcl/tk interface to an existing
:application that I want to avoid to modify for compatibility reasons).
:
:I suppose that what I must do is:
:
: set env(PWD) $drootdir
1. Please !!! When someone is preparing to ask a question here on
comp.lang.tcl, ask the entire question. Many times explaining what
you are trying to do will result in discovering that the question you
are asking is the wrong question.
2. A child process can never set the working directory of the parent.
Doing the set above doesn't change the directory of anything. It may
make the current process _think_ it is in a different directory, but it
is not in fact so.
--
:s Larry W. Virden INET: lvi...@cas.org
:s <URL:http://www.teraform.com/%7Elvirden/> <*> O- "We are all Kosh."
:s Unless explicitly stated to the contrary, nothing in this posting should
:s be construed as representing my employer's opinions.
Gerald W. Lester
Gunnar Törnblom wrote:
> OK, but what I tried to do was really to change the current working dir
> of the parent process because I will execute another (non-tcl) script that
> require another directory (I am building a tcl/tk interface to an existing
> application that I want to avoid to modify for compatibility reasons).
You can't do that. The OSes don't allow it. A process can only effect
itself and its children.
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Scott Kruger
In article <321E43...@cpu.com>, "Gerald W. Lester" <gwle...@cpu.com> writes:
>Gunnar Törnblom wrote:
>
>> OK, but what I tried to do was really to change the current working dir
>> of the parent process because I will execute another (non-tcl) script that
>> require another directory (I am building a tcl/tk interface to an existing
>> application that I want to avoid to modify for compatibility reasons).
>
>You can't do that. The OSes don't allow it. A process can only effect
>itself and its children.
I'm not sure I understand the original question, but it seems to me you can
do the stated goal although not in the manner suggested, at least on UNIX.
In my case, I wrote a script that executes a fortran code in the directory that
has the input file I need. Because of the way the code was written, the input file
has to be in the same directory. So I have:
cd $input_dir
exec ln -sf $code_dir/code . #This links the code to the current directory.
exec code #run the code.
cd $work_dir #Go back to the original directory
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Gerald W. Lester
Scott Kruger wrote:
> In article <321E43...@cpu.com>, "Gerald W. Lester" <gwle...@cpu.com> writes:
> >Gunnar Törnblom wrote:
> >> OK, but what I tried to do was really to change the current working dir
> >> of the parent process because I will execute another (non-tcl) script that
> >> require another directory (I am building a tcl/tk interface to an existing
> >> application that I want to avoid to modify for compatibility reasons).
> >You can't do that. The OSes don't allow it. A process can only effect
> >itself and its children.
> I'm not sure I understand the original question, but it seems to me you can
> do the stated goal although not in the manner suggested, at least on UNIX.
> In my case, I wrote a script that executes a fortran code in the directory that
> has the input file I need. Because of the way the code was written, the input file
> has to be in the same directory. So I have:
> cd $input_dir
> exec ln -sf $code_dir/code . #This links the code to the current directory.
> exec code #run the code.
> cd $work_dir #Go back to the original directory
That was not what I read into the question. What I thought he was
asking was, from the unix shell do:
$ pwd
/home/gwl/test
$ my_tcl foo
$ pwd
/home/gwl/test/foo
Neil Walker
Hi
>Gunnar Törnblom wrote:
>
>> OK, but what I tried to do was really to change the current working dir
>> of the parent process because I will execute another (non-tcl) script that
>> require another directory (I am building a tcl/tk interface to an existing
>> application that I want to avoid to modify for compatibility reasons).
>
If you used expectk you might avoid these problems, because you'd be calling
the other script from inside tcl. As far as I know, expectk still only (only?)
works on UNIX, which could be a problem ...
Cheers
Neil
Donal K. Fellows
In article <321BFD...@senet.abb.se>,
Gunnar Törnblom <gunnar....@senet.abb.se> wrote:
> OK, but what I tried to do was really to change the current working dir
> of the parent process because I will execute another (non-tcl) script that
> require another directory (I am building a tcl/tk interface to an existing
> application that I want to avoid to modify for compatibility reasons).
This would be an _enourmous_ security hole, and consequently cannot be
done. Find a different way of doing what you want...
Donal.
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