/bin/bash - variable substitution.

trey85stang · #1 (**permalink**) 04-21-2009

Is it possible with a bash variable to perform multiple substitution strings to one variable?

I have this variable:
echo $clock
TIMEZONE="US/Central"

What I would like to do with bash only it pull out just the "US" part of the variable.. which could be any number of countries.

this is where I am at:

echo ${clock:10}
US/Central"

echo ${clock:10#*/}
bash: testing: 10#*/: syntax error: operand expected (error token is "/")

echo ${clock#*/}
Central"

So, am I just missing something.. or can I only do one type of substition with a bash variable?

thanks,
Trey

Franklin52 · #2 (**permalink**) 04-21-2009

Try this:

Code:

echo $clock | sed 's!.*"\(.*\)/.*!\1!'

Regards

colemar · #3 (**permalink**) 04-21-2009

Code:

colemar@deb:~$ echo ${clock:10:2}
US

colemar@deb:~$ a=${clock#*\"}
colemar@deb:~$ echo $a
US/Central"
colemar@deb:~$ echo ${a%%/*}
US

trey85stang · #4 (**permalink**) 04-21-2009

Quote:

Originally Posted by Franklin52

Try this:

Code:

echo $clock | sed 's!.*"\(.*\)/.*!\1!'

Regards

thanks, but I was really just wondering if I could do this all with bash.

Quote:

Originally Posted by colemar

Code:

colemar@deb:~$ echo ${clock:10:2}
US

I know that, but the problem lies that US is not alway US thus it can be more then 2 characters long...

colemar · #5 (**permalink**) 04-21-2009

Quote:

Originally Posted by trey85stang

I know that, but the problem lies that US is not alway US thus it can be more then 2 characters long...

Then you must do it in two steps, as outlined above.
I believe there is no way to do it at once with bash parameters substitution.

colemar · #6 (**permalink**) 04-21-2009

Quote:

Originally Posted by colemar

I believe there is no way to do it at once with bash parameters substitution.

Seems to be possible, though ugly:

Code:

colemar@deb:~$ echo ${clock//@(*?=\"|\/*?)/}
US

trey85stang · #7 (**permalink**) 04-21-2009

Quote:

Originally Posted by colemar

Seems to be possible, though ugly:

Code:

colemar@deb:~$ echo ${clock//@(*?=\"|\/*?)/}
US

looks like that will do it, good stuff. I appreciate it. This will save me a lot of work creating a bunch of variables in a script

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