croutonversion

#!/bin/sh -e
# Copyright (c) 2014 The crouton Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

VERSION='unknown'
RELEASE='unknown'
ARCH='unknown'

APPLICATION="${0##*/}"
CHANGES=''
DOWNLOAD=''
DEST="$HOME/Downloads/crouton"
UPDATES=''

BRANCH="${VERSION##*~}"
BRANCH="${BRANCH%%:*}"
COMMIT="${VERSION##*:}"
CHANGESURL="https://github.com/dnschneid/crouton/compare/$COMMIT..."
CROUTONURL='http://goo.gl/cZ2PL'


USAGE="$APPLICATION [options]

Reports the version of crouton installed, checks if updates are available,
and/or launches a changelog.

If no options are specified, outputs crouton version information to STDOUT.

Options:
    -a       Prints the architecture of this chroot to stdout.
    -c       Launches a browser to view the list of changes.
             If -u is specified, only launches if a newer version exists.
    -d       Downloads the latest version of crouton to the location specified.
             If -u is specified, only downloads if the version is newer.
    -f FILE  Changes the destination of the downloaded crouton.
             Default: $DEST
    -h       Prints out usage.
    -r       Prints the release of this chroot to stdout.
    -u       Checks for updates, and prints out the updated version number."


# Function to exit with exit code $1, spitting out message $@ to stderr
error() {
    local ecode="$1"
    shift
    echo "$*" 1>&2
    exit "$ecode"
}

# Process arguments
while getopts 'acdf:ru' f; do
    case "$f" in
    a) echo "$ARCH"; exit 0;;
    c) CHANGES='y';;
    d) DOWNLOAD='y';;
    f) DEST="$OPTARG";;
    r) echo "$RELEASE"; exit 0;;
    u) UPDATES='y';;
    \?) error 2 "$USAGE";;
    esac
done

# No extra parameters
if [ ! "$#" = "$((OPTIND-1))" ]; then
    error 2 "$USAGE"
fi

# Print out version if nothing else specified
if [ -z "$CHANGES$DOWNLOAD$UPDATES" ]; then
    echo "crouton: version $VERSION"
    echo "release: $RELEASE"
    echo "architecture: $ARCH"
    targetfile='/etc/crouton/targets'
    if [ -r "$targetfile" ]; then
        echo "targets: `sed 's/^,//' "$targetfile"`"
    fi
    hostrel='/var/host/lsb-release'
    if [ -r "$hostrel" ]; then
        host="`awk -F= '/_RELEASE_DESCRIPTION=/{print $2}' "$hostrel"`"
    fi
    echo "host: version ${host:-unknown}"
    exit 0
fi

# Print out version to stderr for info
echo "crouton: version $VERSION" 1>&2

latest=''
tmpdir=''
if [ -n "$UPDATES$DOWNLOAD" ]; then
    tmpdir="`mktemp -d --tmpdir=/tmp crouton.XXX`"
    trap "rm -rf --one-file-system '$tmpdir'" INT HUP 0
    echo "Retrieving latest version of crouton" 1>&2
    if ! wget "$CROUTONURL" -O "$tmpdir/crouton" 2>"$tmpdir/log"; then
        cat "$tmpdir/log" 1>&2
        echo "Failed to retrieve latest version of crouton" 1>&2
        exit 1
    fi
    latest="`awk -F"'" '/^VERSION=/{print $2;exit}' "$tmpdir/crouton"`"
fi

# Print out latest version number if requested
if [ -n "$UPDATES" ]; then
    echo "latest: version $latest"
elif [ -n "$latest" ]; then
    echo "latest: version $latest" 1>&2
fi

# Save latest version if requested
if [ -n "$DOWNLOAD" -a ! "$VERSION" = "$latest" ]; then
    echo "Saving latest version to $DEST" 1>&2
    mv -f "$tmpdir/crouton" "$DEST"
fi

# Launch changelog if requested
if [ -n "$CHANGES" -a ! "$VERSION" = "$latest" ]; then
    # Check if changelogs are available from this version / to this branch
    if ! wget "$CHANGESURL$BRANCH" -O/dev/full 2>&1 | grep -q '404 Not Found'; then
        CHANGESURL="$CHANGESURL$BRANCH"
    elif ! wget "${CHANGESURL}master" -O/dev/full 2>&1 | grep -q '404 Not Found'; then
        CHANGESURL="${CHANGESURL}master"
    else
        # Fall back on the main commit log
        CHANGESURL='https://github.com/dnschneid/crouton/commits/'
    fi
    # One of these will probably work...
    for x in exo-open gnome-open kde-open xdg-open \
             sensible-browser x-www-browser www-browser; do
        if hash "$x" 2>/dev/null; then
            browser="$x"
            break
        fi
    done
    if [ -z "$browser" ]; then
        error 2 "No browser found to view $CHANGESURL"
    fi
    # Launch the webpage
    if ! "$browser" "$CHANGESURL"; then
        error 1 "Failed to launch browser to view $CHANGESURL"
    fi
fi

exit 0