uppercase first character in a variable with bash

Question

I want to uppercase just the first character in my string with bash.

foo=\"bar\";

//uppercase first character

echo $foo;

should print \"B

Answer 1

What if the first character is not a letter (but a tab, a space, and a escaped double quote)? We'd better test it until we find a letter! So:

S='  \"ó foo bar\"'
N=0
until [[ ${S:$N:1} =~ [[:alpha:]] ]]; do N=$[$N+1]; done
#F=`echo ${S:$N:1} | tr [:lower:] [:upper:]`
#F=`echo ${S:$N:1} | sed -E -e 's/./\u&/'` #other option
F=`echo ${S:$N:1}
F=`echo ${F} #pure Bash solution to "upper"
echo "$F"${S:(($N+1))} #without garbage
echo '='${S:0:(($N))}"$F"${S:(($N+1))}'=' #garbage preserved

Foo bar
= \"Foo bar=