if [ -d != doesn't work

# if [ -d != ~/.ssh/ ] ; then echo mkdir ~/.ssh/ ; fi
mkdir /root/.ssh/
# ls -ld ~/.ssh/
drwxr-xr-x 2 root root 4096 Jan 5 12:19 /root/.ssh/
#

how come this doesn't work?

 

Because ~ refers to your real user id (the userid you logged on with) and not root ?

 

i logged in as root

 

Looks like '[' and 'test' are not similar: Use:

Code:

if test ! -d ~/.ssh/  ; then echo mkdir ~/.ssh/ ; fi

-d check if a directory exists. You cannot do '-d !='

 

then what does "test" here means?

 

'test' is the equivalent command for '['. In this case it replaces the []. Do

Code:

man test

on your server and you'll see all the options.

 

Also take a look at http://www.tldp.org/LDP/abs/html/tests.html

 

thank you