s3-get

#! /usr/bin/env bash
cat > /dev/null << EndOfLicence
s3-bash
Copyright 2007 Raphael James Cohn

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
in compliance with the License.
You may obtain a copy of the License at
 
 	http://www.apache.org/licenses/LICENSE-2.0
 	
Unless required by applicable law or agreed to in writing, software distributed under the License
is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
or implied. See the License for the specific language governing permissions and limitations under
the License.
EndOfLicence

# Pragmas
set -u
set -e

function printHelpAndExit
{
	exitCode=$1
	printf "%s: version %s\n" "$weAreKnownAs" "$version"
	printf "Part of s3-bash. Latest version is at %s\n" 'http://code.google.com/p/s3-bash/'
	printf "Usage %s: -h\n" "$weAreKnownAs"
	printf "Usage %s: [-vS] [-H file] [-a file] -k key -s file url\n" "$weAreKnownAs"
	printf " Option\tType\tRequirement\tDescription\n"
	printf " -h\t\tprecedent\tprint this help\n"
	printf " -v\t\toptional\tverbose output\n"
	printf " -k\tstring\tmandatory\tAWS Access Key Id\n"
	printf " -s\tfile\tmandatory\tAWS Secret Access Key Id File\n"
	printf " -S\t\toptional\tUse https\n"
	printf " -H\tfile\toptional\tFile to write response headers to\n"
	printf " -a\tfile\toptional\tFile to read Amazon custom headers from (X-Amz-Date is not allowed)\n"
	printf " \turl\tmandatory\trelative url including bucket name and leading slash, eg /bucket/path/to/object?acl. Assumed to be already encoded\n"
	printf "\n"
	printf "Notes\n"
	printf "Specify proxies using a ~/.curlrc file\n"
	printf "Content is returned on stdout\n"
	exit $exitCode
}

function parseOptions
{
	verbose=""
	url=""
	awsAccessKeyId=""
	awsAccessSecretKeyIdFile=""
	protocol="http"
	dumpHeaderFile="/dev/null"
	amazonHeaderFile="/dev/null"
	while getopts "hvk:s:SH:a:" optionName; do		
		case "$optionName" in
			h)	printHelpAndExit 0;;
			v)	verbose="-v";;
			k)	awsAccessKeyId="$OPTARG";;
			s)	awsAccessSecretKeyIdFile="$OPTARG"
				if [ ! -e "$awsAccessSecretKeyIdFile" ]; then
					printErrorHelpAndExit "AWS Secret Key Id file does not exist" $userSpecifiedDataErrorExitCode
				fi;;
			S)	protocol="https";;
			H)	dumpHeaderFile="$OPTARG";;
			a)	amazonHeaderFile="$OPTARG"
				;;
			[?])	printErrorHelpAndExit "Option not recognised" $userSpecifiedDataErrorExitCode;;
		esac
	done
	if [ 1 -eq $OPTIND ]; then
		printErrorHelpAndExit "Internal Error: parseOptions or a parent method in the call stack was not called with $"@"." $internalErrorExitCode
	fi
	let "toShift = $OPTIND - 1"
	shift $toShift
	if [ $# -eq 0 ]; then
		printErrorHelpAndExit "URL not specified" $userSpecifiedDataErrorExitCode
	fi
	url="$1"
	verifyUrl
		
	if [ -z "$awsAccessSecretKeyIdFile" ]; then
		printErrorHelpAndExit "AWS Secret Access Key file not specified" $userSpecifiedDataErrorExitCode
	elif [ -z "$awsAccessKeyId" ]; then
		printErrorHelpAndExit "AWS Access Key Id not specified" $userSpecifiedDataErrorExitCode
	fi
}

function prepareToRunCurl
{
	readonly verb="GET"
	readonly verbToPass="--get"
	readonly contentMD5=""
	readonly contentType=""
}

readonly weAreKnownAs="$(basename $0)"
readonly ourPath="$(dirname $0)"

readonly commonFunctions="$ourPath/s3-common-functions"
if [ -e "$commonFunctions" ]; then
	source "$commonFunctions"
else
	version="Unknown"
	invalidEnvironmentExitCode=4
	printErrorHelpAndExit "$weAreKnownAs: Could not locate file s3-common-functions" $invalidEnvironmentExitCode
fi

main "$@"