apk_fingerprint

#!/usr/bin/env bash

if [[ ! ( # any of the following are not true
        # 1st arg is an existing regular file
        -f "$1" &&
        # ...and it has a .apk extension
        "${1##*.}" == "apk"
        ) ]];
    then
        cat << EOF >&2
    Usage: $(basename "$0") Application.apk
EOF
    exit;
fi

## Exit on use of an uninitialized variable
set -o nounset
## Exit if any statement returns a non-true return value (non-zero)
set -o errexit
## Announce commands
#set -o xtrace

realpath(){
    echo "$(cd "$(dirname "$1")"; echo -n "$(pwd)/$(basename "$1")")";
}

APK="$(realpath $1)"
TMP="$(mktemp -d /tmp/resign.$(basename "$APK" .apk).XXXXX)"

CLEANUP_TEMP=0 # Do not remove this line or "set -o nounset" will error on checks below
#CLEANUP_TEMP=1 # Uncomment this line if you want this script to clean up after itself
cd "$TMP"
[[ $CLEANUP_TEMP -ne 1 ]] && echo "Using temp dir: $TMP"
unzip -q "$APK"
for file in META-INF/*.RSA; do
    keytool -printcert -file "$file"
done
[[ $CLEANUP_TEMP -eq 1 ]] && rm -rf "$TMP"