#!/bin/bash

set -u
set -e

ELINKS="$(/usr/bin/which elinks)" || true

function usage
{
    echo "Usage: $0 -f <function>"
}

function lookup_function
{
    local name="$1"
    local filename="function.$(echo "${name}" | /usr/bin/sed 's/_/-/g').html"

    if [ ! -n "${ELINKS}" ]; then
        echo "elinks not found."
        exit 1;
    fi

    elinks --no-references --no-numbering -dump -dump-color-mode 1 "/usr/share/doc/php/php-chunked-xhtml/${filename}" | less -R
}

opt_f=

# Parse the arguments
while getopts :f: opt ; do
    case ${opt} in
        f)
            opt_f="${OPTARG}"
            ;;
        \?)
            echo "Invalid option -${OPTARG}."
            exit 1
            ;;
        :)
            echo "Missing parameter for -${OPTARG}."
            exit 1
            ;;
    esac
done

if [ -n "${opt_f}" ]; then
    lookup_function "${opt_f}"
else
    usage "$0"
    exit 1
fi