Added several functions to support JoeyBuild.

towel.sh

@@ -39,6 +39,23 @@ tCYAN=6
 #  Global variables used by Towel.
 #
 __tG__PARENTPATH="${BASH_SOURCE[0]}"
+__tG__SUDOPASS=
+
+
+#
+#   Argument helper to process things intended for Towel.
+#
+# Parameters:
+#   ARGS  - All command line arguments passed to script.
+#
+function tArgsHandler() {
+	local __FIRST=$1
+
+	# Is SUDO after us?
+	if [[ "${__FIRST}" == "TOWEL_ASKPASS" ]]; then
+		tSudoAskPass  # Does not return.
+	fi
+}
 
 
 #
@@ -93,6 +110,32 @@ function tCheckPackages() {
 }
 
 
+#
+#   Downloads file.
+#
+# Parameters:
+#
+#   URL  - URL of file to download.
+#   FILE - Optional alternate name to save downloaded file under.
+#
+function tDownload() {
+	local __URL=$1
+	local __FILE=
+
+	tTrim __FILE "$2"
+
+	if [[ -z ${__FILE} ]]; then
+		__FILE=${__URL##*/}
+	fi
+
+	if [[ -e "${__FILE}" ]]; then
+		rm -f "${__FILE}"
+	fi
+
+	wget -O "${__FILE}" ${__URL}
+}
+
+
 #
 #   Escapes a given string so it's safe to write into an XML document.
 #
@@ -111,6 +154,32 @@ function tEscapeXml() {
 }
 
 
+#
+#   Downloads the latest release of a project from GitHub.
+#
+# Parameters:
+#
+#   RESULT     - Variable in which to return the name of the downloaded file.
+#   DEVELOPER  - GitHub developer name that owns the project.
+#   PROJECT    - Which project from that developer to download.
+#   EXTENSION  - Which file extension to download from the release list.
+#
+function tFetchGitHubRelease() {
+	local __RESULT=$1
+	local __DEVELOPER=$2
+	local __PROJECT=$3
+	local __EXTENSION=$4
+	local __URL=$(curl -s https://api.github.com/repos/${__DEVELOPER}/${__PROJECT}/releases \
+		| grep "browser_download_url.*${__EXTENSION}" \
+		| cut -d : -f 2,3 \
+		| tr -d \" \
+		| head -n 1)
+	local __FILE=${__URL##*/}
+	tDownload ${__URL}
+	eval $__RESULT=\${__FILE}
+}
+
+
 #
 #   Displays a whiptail-based file browser for selecting a particular type of file.
 #
@@ -266,6 +335,83 @@ function tGetTowelPath() {
 }
 
 
+#
+#   Runs program with sudo asking for password using a nice dialog box.
+#
+# Parameters:
+#
+#   ARGS - Command to execute with sudo.
+#
+function tSudo() {
+	local __ARGS="$@"
+	local __ASK="$(mktemp --suffix=.sh -q)"
+
+	if [[ "${__tG__SUDOPASS}x" == "x" ]]; then
+		cat <<- ASKPASS > "${__ASK}"
+			#!/bin/bash
+			"${BASH_SOURCE[1]}" TOWEL_ASKPASS
+		ASKPASS
+	else
+		cat <<- ASKPASS > "${__ASK}"
+			#!/bin/bash
+			echo "${__tG__SUDOPASS}"
+		ASKPASS
+	fi
+
+	chmod +x "${__ASK}"
+
+	if [[ "${__ARGS}x" == "x" ]]; then
+		SUDO_ASKPASS="${__ASK}" sudo -A -v
+	else
+		SUDO_ASKPASS="${__ASK}" sudo -A ${__ARGS}
+	fi
+
+	rm "${__ASK}"
+}
+
+
+#
+#   Helper function for asking for password using a nice dialog box.
+#
+# Parameters:
+#
+#   None.
+#
+function tSudoAskPass() {
+	local __RET=
+	local __PASSWORD=
+
+	set +e
+	__PASSWORD=$(
+		whiptail --passwordbox "\n$(basename "${BASH_SOURCE[1]}") needs superuser access.\n\nPlease enter your password:" 12 60 --title "Need Root" 3>&1 1>&2 2>&3
+	)
+	__RET=$?
+	set -e
+
+	if [[ ${__RET} -ne 0 ]]; then
+		echo "Cannot continue without superuser access." 1>&2
+		exit 1
+	fi
+
+	printf "${__PASSWORD}\n"
+	exit 0
+}
+
+
+#
+#   Allows specifying the sudo password for automated installs.
+#
+# Parameters:
+#
+#   PASSWORD - The sudo password to use.
+#
+function tSudoSetPassword() {
+	local __PASSWORD=$1
+
+	__tG__SUDOPASS=${__PASSWORD}
+}
+
+
 #
 #   Removes whitespace from the beginning and end of a string.
 #