[Tutor] Re: python from shell

[Lloyd Kvam]

Using /usr/bin/env is generally best for people.  This discussions started
because it failed for a CGI python script.  A script that needs to run
using a server's environment may not have a "normal" path.  Much depends on
the local security policies and the sysadmin.  For those cases, if the
environment is totally outside your control, pointing directly to python
can be preferable.

lumbricus@gmx.net wrote:

>>On Tue, Jul 09, 2002 at 09:18:25AM -0500, SA wrote:
>>
> 
> [ snip ]
> 
> 
>>Here's the difference :
>>
>>/usr/bin/env is a program that searches the $PATH to find the program
>>given as it's first argument.  Then it exec's it on the input
>>(script).
>>
>>Using /usr/bin/env means that your script will automagically run on
>>any person's system *IFF* the 'python' found first in the $PATH is the
>>one you wanted to use.  It also means (due to limitations in
>>
>                                                 ^^^^^^^^^^^
> what do you mean?
> 
> 
>>linux/bash)
>>
>   ^^^^^^^^^^
> now which one?
> 
> 
>>that you can't pass any arguments to python itself (such
>>as -u or -OO).
>>
> 
>>From 'man env' on OSF1
> (no matter which shell ;-)
> 
> "  env, printenv - Displays or sets the current environment, or displays the
>   values of environment variables
> 
> SYNOPSIS
> 
>   Current Syntax
> 
>   env [-i] [name=value...] [command] [args...]
> 
> ...
> 
>   args
>       Arguments to be passed to command when it is executed.
> 
> "
> 
> It works for me.
> 
> 
>>Using the full path to the interpreter ensures that you'll be using
>>the python you want to use.
>>
> 
> _Iff_ it is there. On my system for example python is in
> /usr/local/bin. So your scripts won't run
>  
> 
>>For example, on a debian woody system, /usr/bin/python is a symlink to
>>/usr/bin/python2.1, and it is also possible for the user to have
>>/usr/bin/python2.2 as well.  On a RH 7.x system, 'python' (is it in
>>/usr/bin ?) is version 1.5 wherease 'python2' is version
>>2.<something>.  Using the env trick will yield different results on
>>different systems, and using the full path isn't compatible with all
>>systems.
>>
> 
> ACK
>  
> 
>>Pay your money and take your choice :-) (as one of my profs likes to say)
>>
> 
> But env(1) has the advantage that it sets the environment as the
> command (python) needs it - PYTHONPATH, PYTHONHOME or the like.
>  
> 
>>I choose to use the absolute path and explicitly specify the version I
>>want.  Then again, I also use debian and for debian-packaged programs
>>that is also the Policy.
>>
> 
> But this fails, if the specified version isn't there. 
> I'd prefer env(1).
>  
> [ snip ]
> 
> HAND and Greetings,
> J"o!
> 
> 


-- 
Lloyd Kvam
Venix Corp.
1 Court Street, Suite 378
Lebanon, NH 03766-1358

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603-443-6155
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