[SOLVED] Bash: one-liner cd to dir1 or dir2, then execute command.

gctaylor1 · 08-06-2015, 05:47 PM

I'm trying to write a one liner(that's not obnoxiously long) to cd into either dir1 or dir2 and then run a command into which ever directory exists.

Something like this(pseudo code):

Code:

ssh remote_machine 'if [[ -d /opt/abc/def/ghi/dir1 || -d /opt/abc/def/ghi/dir2; then cd <which ever dir found>; fi; ./command.sh'

I could live with the length of the above if I could capture whether it was dir1 that was found or dir2 so I could change to it.

I think if I could find a clever use of change directory, I wouldn't even need the if conditional.

Any suggestions?

astrogeek · 08-06-2015, 06:10 PM

How about something like this (ssh part not shown)...
(Modified and thanks to Keith Hedger too!)

Code:

(cd /opt/abc/def/dir1 || cd /opt/abc/def/dir2; ./command.sh)

This will let you see any error messages, but see next post to suppress those.

Keith Hedger · 08-06-2015, 06:16 PM

Try

Code:

( cd /tmp/w || cd /tmp/y;touch zz ) 2>/dev/null

It first trys to cd to /tmp/w if this fails it cds to /tmp/y and then touches the file zz

Keith Hedger · 08-06-2015, 06:18 PM

sorry astrogeek you posted just about the same as me as i was typing

astrogeek · 08-06-2015, 06:24 PM

Quote:

Originally Posted by Keith Hedger

sorry astrogeek you posted just about the same as me as i was typing

Ditto...

gctaylor1 · 08-06-2015, 06:31 PM

These are both great. Thanks so much.

Gary

astrogeek · 08-06-2015, 06:48 PM

Glad that helped!

It is worth noting that should BOTH cd's fail it will still try to run ./command.sh from the login user home directory. That file probably will not exist, but if it did... keep that in mind.

To avoid that possibility:

Code:

((cd /opt/abc/def/dir1 && ./command.sh) || (cd /opt/abc/def/dir2 && ./command.sh))

(full parenthesis optional, but good habit...)

Keith Hedger · 08-06-2015, 06:56 PM

To prevent the command being run if neither dir exists use

Code:

( cd /tmp/x || cd /tmp/y && touch zz ) 2>/dev/null

In this if both cd's fail the touch is not run if either of the two cd's succeed the touch is run.
Well spotted astrogeek.

Keith Hedger · 08-06-2015, 06:58 PM

This is getting spooky now !

astrogeek · 08-06-2015, 07:00 PM

Quote:

Originally Posted by Keith Hedger

This is getting spooky now !

I think I hear the fat lady singing... no wait - it's Elvis!

Maybe great minds truly do think alike! Yea, that must be it...