bash: how to get port number from the "port: 5432," line (no quotes)

x.sh

# Nr. 1
p='port:     5432,'
echo ${p//[!0-9]/}

# Nr. 2
IFS=':, ' read -r _ p <<< "port:     5432,"

# Nr. 3
awk -F[,:] '{print $2+0}' <<< "port:     5432,"

# Nr. 4
p='port:     5432,'
[[ $p =~ (port:)( )?*([0-9]?*), ]] && echo ${BASH_REMATCH[3]}

# Nr. 5
p='port:     5432,'
printf '%d\r%d\n' ${p} 2>/dev/null

# Nr. 6
p='port:     5432,';
: $p; echo ${_%,}

# Nr. 7
p='port:     5432,'
( set -- ${p%,}; echo ${2} )