How to trim whitespace from a Bash variable?

Question

I have a shell script with this code:

var=`hg st -R \"$path\"`
if [ -n \"$var\" ]; then
    echo $var
fi

But the conditional code always ex

Answer 1

This worked for me:

text="   trim my edges    "

trimmed=$text
trimmed=${trimmed##+( )} #Remove longest matching series of spaces from the front
trimmed=${trimmed%%+( )} #Remove longest matching series of spaces from the back

echo "<$trimmed>" #Adding angle braces just to make it easier to confirm that all spaces are removed

#Result

To put that on fewer lines for the same result:

text="    trim my edges    "
trimmed=${${text##+( )}%%+( )}