Decipher Script

Shell Programming and Scripting
1

Hi Guys,

I am running solaris and I need help in deciphering the following commands:

dir_t1=`echo $0|nawk -F'/' '{print NF}'`
dir_t2=`expr $dir_t1- 1`
dir_t3=`echo $0|cut -d'/' -f1-$dir_t2`
export dir_t2

What will be the value for dir_t3?

Please help !!!!!!!!!!!!!!!

2

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Wouldn't it be easier to simply run the script and see what it does?

3

Thanks for the reply and the comments.

I should also note that those commands are inside the script.

I can't test the script as the script exists on production system.

I just want to get the interpretation of those commands then I will be able to get the gist of the script.

Thanks

4

My guess: the directory containing the script executed ...

[house@universe] more Desktop/test.sh
#! /bin/bash
echo $0
dir_t1=`echo $0|nawk -F'/' '{print NF}'`
echo $dir_t1
dir_t2=`expr $dir_t1 - 1`
echo $dir_t2
dir_t3=`echo $0|cut -d'/' -f1-$dir_t2`
echo $dir_t3
exit 0
[house@universe] sh Desktop/test.sh
Desktop/test.sh
2
1
Desktop
5

dr.house is right.
The end product is the same as this single line which finds the directory name of the command used to invoke the script:

dir_t3="`dirname $0`"

If the script was started with a full path name, the output is the full path of the directory containing the script. If the script was started with "./scriptname", the output is just "." .

6

Thanks a lot for the reply...