To convert function name from snake case to camel case or pascal case in go on OS X with bash 3

convertFunctionFromSnakeTo.sh

#!/bin/bash

if [[ $# -eq 1 ]] ;then
    case $1 in
        -c) option="camel" ;;
        -p) option="pascal" ;;
        *) echo "This option $1 is not supported."; exit 1 ;;
    esac
else
    echo "Give an option -c (Camel case) or -p (Pascal case)."
    exit -1
fi

for f in $(find . -name "*.go"); do
    for g in $(grep -h ^func $f | sed -n 's/func \([^()]*\) *(.*/\1/p' | grep _ ) $(grep -h ^func $f | sed -n 's/func (.*) \([^()]*\) *(.*/\1/p' | grep _ ); do
    
        snake=$g
        if [[ $option = "camel" ]]; then
            tocase=$(echo $g | perl -pe "s/_(.)/\u\1/g")
        elif [[ $option = "pascal" ]]; then
            tocase=$(echo $g | perl -pe "s/_(.)/\u\1/g; s/^(.)/\u\1/g")
        fi
    
        echo "$snake -> $tocase"
        for h in $(find . -name "*.go"); do
            # BSD sed
            sed -i "" "s/$snake/$tocase/g" $h
        done
    
    done
done