OT: bash question

[Mike Wright]

Hi all,

Not sure where to find the answer to this question.  Google wasn't 
helpful.  The users on this list are a great repository of knowledge so 
I thought to try here.

Is there a bash command that tells an executing script what *its* path 
is?  Not the path where the user is but where the script is.  If not 
that then a series of commands that yield the same result?  Maybe some 
way of using 'ps'?

Has me stumped and my dog-eared "UNIX in a Nutshell" hasn't exposed the 
goodies either ;)

TIA,
Mike Wright

[Bruno Wolff III]

On Mon, Jan 31, 2011 at 12:32:24 -0800,
  Mike Wright <mike.wright(a)mailinator.com&gt; wrote:
>  Hi all,
>  
>  Not sure where to find the answer to this question.  Google wasn't 
>  helpful.  The users on this list are a great repository of knowledge so 
>  I thought to try here.
>  
>  Is there a bash command that tells an executing script what *its* path 
>  is?  Not the path where the user is but where the script is.  If not 
>  that then a series of commands that yield the same result?  Maybe some 
>  way of using 'ps'?
>  
>  Has me stumped and my dog-eared "UNIX in a Nutshell" hasn't exposed the 
>  goodies either ;) 
What is the high level purpose for wanting this information? There may be
other ways to solve that problem.

[Mike Wright]

Bruno Wolff III wrote:
>  On Mon, Jan 31, 2011 at 12:32:24 -0800,
>    Mike Wright <mike.wright(a)mailinator.com&gt; wrote:
> > Hi all,
> >
> > Not sure where to find the answer to this question.  Google wasn't 
> > helpful.  The users on this list are a great repository of knowledge so 
> > I thought to try here.
> >
> > Is there a bash command that tells an executing script what *its* path 
> > is?  Not the path where the user is but where the script is.  If not 
> > that then a series of commands that yield the same result?  Maybe some 
> > way of using 'ps'?
> >
> > Has me stumped and my dog-eared "UNIX in a Nutshell" hasn't exposed the
>
> > goodies either ;)
>  
>  What is the high level purpose for wanting this information? There may be
>  other ways to solve that problem. 
Awesome, Bruno, thanks for responding.

I'm trying to create a self-contained app in that it is both a data 
repository and also the location of its binary (BIN/runme, DATA/) so 
that the application could be installed anywhere in user space and still 
be able to find itself.  A link in /usr/local/bin (wherever) would point 
to the install location.

Ideas?

Mike

[Bruno Wolff III]

On Mon, Jan 31, 2011 at 12:55:36 -0800,
  Mike Wright <mike.wright(a)mailinator.com&gt; wrote:
>  
>  I'm trying to create a self-contained app in that it is both a data 
>  repository and also the location of its binary (BIN/runme, DATA/) so 
>  that the application could be installed anywhere in user space and still 
>  be able to find itself.  A link in /usr/local/bin (wherever) would point 
>  to the install location. 
That rules out doing some things with the fd directly, since that fd doesn't
point to the data.

If you know the program is being run via a sym link, then the readlink based
suggestions sound like they will do what you want.

[Suvayu Ali]

On Mon, Jan 31, 2011 at 12:32 PM, Mike Wright
<mike.wright(a)mailinator.com&gt; wrote:
>  s there a bash command that tells an executing script what *its*
> path
>  is?  Not the path where the user is but where the script is. 
$ cat ./test.sh
#!/bin/bash

echo $0 is the script
echo `dirname $0` is the script location

exit $?

HTH

-- 
Suvayu

Open source is the future. It sets us free.

bash question

[compdoc]

>  Is there a bash command that tells an executing script what *its*
> path is? 
echo $PWD

bash question

[Patrick O'Callaghan]

On Mon, 2011-01-31 at 14:49 -0700, compdoc wrote:
>  > Is there a bash command that tells an executing script what
> *its* path is?
>  
>  echo $PWD 
No, that just tells where it was executed from. The OP wants to know
where the script actually lives.

poc

bash question

[fedora]

dirname $0

suomi

On 2011-02-01 13:03, Patrick O'Callaghan wrote:
>  On Mon, 2011-01-31 at 14:49 -0700, compdoc wrote:
> >> Is there a bash command that tells an executing script what *its* path is?
> >
> > echo $PWD
>
>  No, that just tells where it was executed from. The OP wants to know
>  where the script actually lives.
>
>  poc
>

bash question

[Bob McGowan]

On 02/01/2011 05:23 AM, fedora wrote:
>  dirname $0
>  
>  suomi
>  
>  On 2011-02-01 13:03, Patrick O'Callaghan wrote:
> > On Mon, 2011-01-31 at 14:49 -0700, compdoc wrote:
> >>> Is there a bash command that tells an executing script what *its* path is?
> >>
> >> echo $PWD
> >
> > No, that just tells where it was executed from. The OP wants to know
> > where the script actually lives.
> >
> > poc
> > 
The value of $0 on a Linux system will be the full path to where the
script was found, so 'dirname $0' works.

However, bash runs on other OS's (Solaris for one), and Solaris does not
provide the full path in $0, you only get the name of the script.

So be careful if you're writing code that needs to be portable.

-- 
Bob McGowan