In Bash, how can I check if a string begins with some value?

itemprop="text">

I would like to check if a string
begins with "node" e.g. "node001". Something
like

if [ $HOST ==
            user* ]
 then
 echo
            yes
fi

How
can I do it correctly?

/>

I further need to combine expressions to
check if HOST is either "user1" or begins with
"node"

if [ [[ $HOST == user1 ]]
            -o [[ $HOST == node* ]] ];
then
echo
            yes
fi

> > > -bash: [: too many
            arguments

How
can I do it correctly?

itemprop="text">

class="normal">Answer

This
snippet on the rel="noreferrer">Advanced Bash Scripting Guide
says:

# The == comparison operator
            behaves differently within a double-brackets
# test than within single
            brackets.

[[ $a == z* ]] # True if $a starts with a "z" (wildcard
            matching).
[[ $a == "z*" ]] # True if $a is equal to z* (literal
            matching).

So
you had it nearly correct; you needed double
brackets, not single brackets.

/>

With regards to your second question, you can write
it this
way:

HOST=user1
if [[
            $HOST == user1 ]] || [[ $HOST == node* ]] ;

then
 echo
            yes1
fi

HOST=node001
if [[ $HOST == user1 ]] ||
            [[ $HOST == node* ]] ;
then
 echo
            yes2
fi

Which
will
echo

yes1
yes2

Bash's
if syntax is hard to get used to (IMO).