How can a script know its directory location ?

[AmitVJ]

Hi,

I have scripts 'a' and 'b' in a directory, say, /home/myhome. Now /home/myhome is not in the $PATH, so i have to invoke the script with the full path. script 'a' calls script 'b'. I can call it as /home/myhome/b inside 'a'. But tomorrow if i move the whole setup to, say, /home/yourhome, i will have to change the script 'a'. Is their any command, system utility or code by which inside 'a' i can know what its parent directory is and then using that parent directory i can invoke script 'b' from inside 'a'.

Hope i have made the question clear. Please let me know if you need further details / clarifications.

Thanks,
Amit.

 

[RobJordan]

pwd

OR

pwd -P (if you have links, this will show the absolute path)

Robert Robert G. Jordan

Robert@JORDAN2000.com

http://www.JORDAN2000.com

Unix Sys Admin
Chicago, Illinois U.S.A.

 

[RobJordan]

this may also work for you

env|grep PWD|awk -F"=" '{print $2}' Robert G. Jordan

Robert@JORDAN2000.com

http://www.JORDAN2000.com

Unix Sys Admin
Chicago, Illinois U.S.A.

 

[RobJordan]

this may also work for you

echo $PWD
Robert G. Jordan

Robert@JORDAN2000.com

http://www.JORDAN2000.com

Unix Sys Admin
Chicago, Illinois U.S.A.

 

[bjverzal]

or p=`pwd`

 

[pcunix]

No, I don't think that helps him.

None of that tells him where the script is; it tells him where HE is when he invokes the script.


I think he wants "dirname $0" instead. Tony Lawrence
SCO Unix/Linux Resources

http://pcunix.com

tony@pcunix.com

 

[mrn]

create a VAR in the users .profile

a=/your/full/path/of/the/script;export a

then just use $a/scriptname to execute.

You then only need to change one thing if you move your scripts.

P.S. you can also use ./ in front of the script to execute it in it's current directory if the directory is not in the PATH

Mike

--
| Mike Nixon
| Unix Admin
|

http://www.instantflashshop.com

----------------------------

 

[AmitVJ]

Hi,

I guess 'pcunix' has understood my requirement more appropriately. There is one small issue though. In my initial mail i have said that the script directory will not be in the path. in that case, the user will be running the script 'a' with full path (absolute or relative) and i will get what i want by `dirname $0`. But, just in case if the script is in $PATH, then the user may invoke it by the script name alone. Here the `dirname $0` doesn't give me what i want. Is there any generalization to this so that i dont have to bother whether the script 'a' is in user's $PATH or not and whether the user executes the script by full path or just the name. I should be able to find what its location is inside the script. Is there are a way?

And yes, thank you all for taking time in answering my query.

Thanks,
Amit.

 

[mrn]

But If you can't find the script in the first place, how can you expect the script to know where it is? Or am I getting the wrong end of the stick? --
| Mike Nixon
| Unix Admin
|

http://www.instantflashshop.com

----------------------------

 

[RobJordan]

#!/usr/bin/ksh

SCRIPT_NAME=$0
echo "SCRIPT NAME: $SCRIPT_NAME"
ABSOLUTE_LOC=`which $SCRIPT_NAME`
echo "ABSOLUTE LOC: $ABSOLUTE_LOC"

This should work if the full path is given:
/usr/bin/ls

or
if the script dir is in the path

it won't work if your user does
something like . script or ./script

Robert Robert G. Jordan

Robert@JORDAN2000.com

http://www.JORDAN2000.com/scripts

Unix Sys Admin
Chicago, Illinois U.S.A.

 

[RobJordan]

This may work. Let me know.

Robert

# cat script_a
#!/usr/bin/ksh

echo "Doing some stuff..."

SCRIPT_NAME=$0
echo "SCRIPT NAME: $SCRIPT_NAME"
COMMAND=`echo $SCRIPT_NAME|awk -F"/" '{print $NF}'`

FIRST_CHAR=`echo $SCRIPT_NAME|cut -c1`
echo "FIRST CHAR: $FIRST_CHAR"

if [ "$FIRST_CHAR" = "." ]
then
SCRIPT_DIR=$PWD
else
SCRIPT_DIR=`echo $SCRIPT_NAME|awk -F "/$COMMAND" '{print $1}'`
fi

echo "Executing ${SCRIPT_DIR}/script_b..."
${SCRIPT_DIR}/script_b

# cat script_b
#!/usr/bin/ksh

echo "Doing some more stuff..."

Test 1
# ./script_a
Doing some stuff...
SCRIPT NAME: ./script_a
FIRST CHAR: .
Executing /home/u273258/scripts/script_b...
Doing some more stuff...

Test 2
# cd /tmp
root@awhq6394 [/tmp]
# /home/u273258/scripts/script_a
Doing some stuff...
SCRIPT NAME: /home/u273258/scripts/script_a
FIRST CHAR: /
Executing /home/u273258/scripts/script_b...
Doing some more stuff...
Robert G. Jordan

Robert@JORDAN2000.com

http://www.JORDAN2000.com/scripts

Unix Sys Admin
Chicago, Illinois U.S.A.

 

[pcunix]

> But, just in case if the script is in $PATH, then the user
> may invoke it by the script name alone. Here the `dirname $
> 0` doesn't give me what i want.

Huh? "dirname $0" gives you the same results whether the command is in the PATH or is invoked specifically with an absolute PATH- at least it does in shells I've used.

???? Tony Lawrence
SCO Unix/Linux Resources

http://pcunix.com

tony@pcunix.com