AppleScript: How to let AppleScript use the same environment as Bash shell does?

Question

Howdy!
I can run AppleScript from Bash shell.
I can also run Bash shell from AppleScript.
So my question is when I run a Bash shell script from AppleScript, I am hit with a path problem.
Suppose my AppleScript is under ~user/a.scpt. I want my AppleScript to know its current path (i.e. ~user/a.scpt).
So a quick snippet test in my AppleScript shows that AppleScript always begins from the root directory:
do shell script "pwd"
So let's do a workaround AppleScript like this:
tell application "Finder" to set currentDir to (target of front Finder window) as text
do shell script "cd " & (quoted form of POSIX path of currentDir) & "; pwd"
This works. However, this approach poses a potential danger.
Suppose when I run this AppleScript for a bash script, I inadvertently clicked other Finder Window. That would result in execution of bash script in that newly clicked Finder Window, resulting in a big mess.
Is there a better way to let the AppleScript to know its current path?

Answer 1

The following is what your Applescript environment looks like, so plan accordingly.  If you want your Applescripts to be portable to other user environments, you should NOT depend on your environment, but rather embed all the environment knowledge you need into your script.
Applescript "do shell script" environment
pwd:
/bin/ls -dlaeO@ .
drwxr-xr-x  36 root  wheel  - 1292 Feb 28 09:58 .
    /usr/bin/id -a
uid=501(raharris)
gid=20(staff)
groups=20(staff),
402(com.apple.sharepoint.group.1),
12(everyone),
61(localaccounts),
79(_appserverusr),
80(admin),
81(_appserveradm),
98(_lpadmin),
403(com.apple.sharepoint.group.2),
33(_appstore),
100(_lpoperator),
204(_developer),
398(com.apple.access_screensharing),
399(com.apple.access_ssh)
$#
0
$0
/path/to/your/shell/script
printenv:      
SHELL=/bin/bash
TMPDIR=/var/folders/4t/t1djbq6j5pj951x44l9hwxtc0000gn/T/
Apple_PubSub_Socket_Render=/tmp/launch-mSKKJo/Render
USER=<username_running_the_Applescript>
SSH_AUTH_SOCK=/tmp/launch-7D4zpF/Listeners
__CF_USER_TEXT_ENCODING=0x1F5:0:0
PATH=/usr/bin:/bin:/usr/sbin:/sbin
__CHECKFIX1436934=1
PWD=/
HOME=/Users/<home_dir_of_running_user>
SHLVL=2
LOGNAME=<username_running_the_Applescript>
DISPLAY=/tmp/launch-qKucki/org.macosforge.xquartz:0
_=/usr/bin/printenv
Message was edited by: BobHarris