Extract parts of current working directory as variable

Question

I googled for several hours and could not find a solution for the following issue (at least I did not find one I could understand and adapt).

My cwd is:

/home/ubuntu/data/modelling/Iamvariable/Var1/PRODUCTION/ANALYSIS/Var2/DIHEDRALS

and I need to extrakt the "text" behind Var1 and Var2.

I would like to scan the pwd output from right to left since the file path starting could change but the path starting after Iamvaribale will stay always the same. By means of number of elements in path and except Iamvaribale (and of course Var1 and Var2) also the folder names will stay the same.

How can I achieve this in a bash sricpt?

Var1 = 
Var2 =

edit:

/home/ubuntu/data/modelling/Iamvariable/Var1/PRODUCTION/ANALYSIS/Var2/DIHEDRALS

basically everything in capital letters is fixed. If there is no easy solution where

/home/ubuntu/data/modelling

is not fixed this is OK to be set as fixed. But it would be better to have it not fixed, to have it more flexible.

choroba · Accepted Answer · 2018-01-15T12:46:09.937

2

Use parameter expansion:

#!/bin/bash
path=/home/ubuntu/data/modelling/Iamvariable/Var1/PRODUCTION/ANALYSIS/Var2/DIHEDRALS
var1=${path%/PRODUCTION/ANALYSIS/*}
var1=${var1##*/}
echo "$var1"

var2=${path#*/PRODUCTION/ANALYSIS/}
var2=${var2%/*}
echo "$var2"

# removes from the beginning, % from the end of the parameter. Doubling the character means the largest possible string will be removed.

edited Jan 15 '18 at 12:46

answered Jan 15 '18 at 10:40

choroba

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Could you explain further how does `var1=${var1%%/*}` work? Thanks :) – M. Becerra Jan 15 '18 at 10:49
Thanks for your quick answer! For Var 2 I understand that this will work out but for Var1 I don't. How can search for something whitch is variable. Maybe I translated wrong. With that expression I meant that on this position the folder could be namend as anything. – David Schroeder Jan 15 '18 at 11:06
In theory we could read out what is after modelling and put this temporary var as search for var1. However I would like to have it, if possible, more robust since every thing before "Iamvarible" could be changed – David Schroeder Jan 15 '18 at 11:12
Can you give some examples? What parts of the path are fixed? – choroba Jan 15 '18 at 12:09
I added examples above. – David Schroeder Jan 15 '18 at 12:33
another idea could be to use cd ../.. to go to the position of interrest and perform the parameter expansion as mentioned above. It looks a bit messy then. However if there is a better solution for that, this would be good. – David Schroeder Jan 15 '18 at 12:39
@DavidSchroeder: Check the update. – choroba Jan 15 '18 at 12:46
I just noticed, it workes perfect thanks – David Schroeder Jan 15 '18 at 13:08

Extract parts of current working directory as variable

1 Answers1