+#!/bin/bash
+# Desc: Prints latest block from bitcoin-cli
+# Usage: bkbtcblockclock
+# Output: stdout: timestamped block numbers
+# Depends: bitcoin-cli (from bitcoind), jq, gnu coreutils 8.30
+# Version: 0.0.1
+
+#==BEGIN Define script parameters==
+delay="1"
+#===BEGIN Define variables===
+declare -Ag appRollCall # Associative array for storing app status
+declare -Ag fileRollCall # Associative array for storing file status
+declare -Ag dirRollCall # Associative array for storing dir status
+#===END Define variables===
+
+
+#===BEGIN Declare local script functions===
+yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
+die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
+try() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
+checkapp() {
+ # Desc: If arg is a command, save result in assoc array 'appRollCall'
+ # Usage: checkapp arg1 arg2 arg3 ...
+ # Version: 0.1.1
+ # Input: global assoc. array 'appRollCall'
+ # Output: adds/updates key(value) to global assoc array 'appRollCall'
+ # Depends: bash 5.0.3
+ local returnState
+
+ #===Process Args===
+ for arg in "$@"; do
+ if command -v "$arg" 1>/dev/null 2>&1; then # Check if arg is a valid command
+ appRollCall[$arg]="true";
+ if ! [ "$returnState" = "false" ]; then returnState="true"; fi;
+ else
+ appRollCall[$arg]="false"; returnState="false";
+ fi;
+ done;
+
+ #===Determine function return code===
+ if [ "$returnState" = "true" ]; then
+ return 0;
+ else
+ return 1;
+ fi;
+} # Check that app exists
+checkfile() {
+ # Desc: If arg is a file path, save result in assoc array 'fileRollCall'
+ # Usage: checkfile arg1 arg2 arg3 ...
+ # Version: 0.1.1
+ # Input: global assoc. array 'fileRollCall'
+ # Output: adds/updates key(value) to global assoc array 'fileRollCall';
+ # Output: returns 0 if app found, 1 otherwise
+ # Depends: bash 5.0.3
+ local returnState
+
+ #===Process Args===
+ for arg in "$@"; do
+ if [ -f "$arg" ]; then
+ fileRollCall["$arg"]="true";
+ if ! [ "$returnState" = "false" ]; then returnState="true"; fi;
+ else
+ fileRollCall["$arg"]="false"; returnState="false";
+ fi;
+ done;
+
+ #===Determine function return code===
+ if [ "$returnState" = "true" ]; then
+ return 0;
+ else
+ return 1;
+ fi;
+} # Check that file exists
+checkdir() {
+ # Desc: If arg is a dir path, save result in assoc array 'dirRollCall'
+ # Usage: checkdir arg1 arg2 arg3 ...
+ # Version 0.1.1
+ # Input: global assoc. array 'dirRollCall'
+ # Output: adds/updates key(value) to global assoc array 'dirRollCall';
+ # Output: returns 0 if app found, 1 otherwise
+ # Depends: Bash 5.0.3
+ local returnState
+
+ #===Process Args===
+ for arg in "$@"; do
+ if [ -d "$arg" ]; then
+ dirRollCall["$arg"]="true";
+ if ! [ "$returnState" = "false" ]; then returnState="true"; fi
+ else
+ dirRollCall["$arg"]="false"; returnState="false";
+ fi
+ done
+
+ #===Determine function return code===
+ if [ "$returnState" = "true" ]; then
+ return 0;
+ else
+ return 1;
+ fi
+} # Check that dir exists
+displayMissing() {
+ # Desc: Displays missing apps, files, and dirs
+ # Usage: displayMissing
+ # Version 0.1.1
+ # Input: associative arrays: appRollCall, fileRollCall, dirRollCall
+ # Output: stderr: messages indicating missing apps, file, or dirs
+ # Depends: bash 5, checkAppFileDir()
+ local missingApps value appMissing missingFiles fileMissing
+ local missingDirs dirMissing
+
+ #==BEGIN Display errors==
+ #===BEGIN Display Missing Apps===
+ missingApps="Missing apps :";
+ #for key in "${!appRollCall[@]}"; do echo "DEBUG:$key => ${appRollCall[$key]}"; done
+ for key in "${!appRollCall[@]}"; do
+ value="${appRollCall[$key]}";
+ if [ "$value" = "false" ]; then
+ #echo "DEBUG:Missing apps: $key => $value";
+ missingApps="$missingApps""$key ";
+ appMissing="true";
+ fi;
+ done;
+ if [ "$appMissing" = "true" ]; then # Only indicate if an app is missing.
+ echo "$missingApps" 1>&2;
+ fi;
+ unset value;
+ #===END Display Missing Apps===
+
+ #===BEGIN Display Missing Files===
+ missingFiles="Missing files:";
+ #for key in "${!fileRollCall[@]}"; do echo "DEBUG:$key => ${fileRollCall[$key]}"; done
+ for key in "${!fileRollCall[@]}"; do
+ value="${fileRollCall[$key]}";
+ if [ "$value" = "false" ]; then
+ #echo "DEBUG:Missing files: $key => $value";
+ missingFiles="$missingFiles""$key ";
+ fileMissing="true";
+ fi;
+ done;
+ if [ "$fileMissing" = "true" ]; then # Only indicate if an app is missing.
+ echo "$missingFiles" 1>&2;
+ fi;
+ unset value;
+ #===END Display Missing Files===
+
+ #===BEGIN Display Missing Directories===
+ missingDirs="Missing dirs:";
+ #for key in "${!dirRollCall[@]}"; do echo "DEBUG:$key => ${dirRollCall[$key]}"; done
+ for key in "${!dirRollCall[@]}"; do
+ value="${dirRollCall[$key]}";
+ if [ "$value" = "false" ]; then
+ #echo "DEBUG:Missing dirs: $key => $value";
+ missingDirs="$missingDirs""$key ";
+ dirMissing="true";
+ fi;
+ done;
+ if [ "$dirMissing" = "true" ]; then # Only indicate if an dir is missing.
+ echo "$missingDirs" 1>&2;
+ fi;
+ unset value;
+ #===END Display Missing Directories===
+
+ #==END Display errors==
+} # Display missing apps, files, dirs
+getBlockNum() {
+ # depends: yell(), die(), try()
+ blockNum="$(try bitcoin-cli getblockchaininfo | try jq '."headers"')"
+ echo "$blockNum";
+}
+printNum() {
+ # depends: yell(), die(), try()
+ # usage printNum arg1
+ echo "[$(date --iso-8601=seconds)]:$1"
+ }
+main() {
+ # Depends: bitcoin-cli (from bitcoind)
+ # Depends: getBlockNum(), printNum()
+
+ # Check dependencies
+ if ! checkapp bitcoin-cli jq date; then
+ yell "ERROR:Apps missing." >&2;
+ displayMissing;
+ exit 1;
+ fi;
+
+ lastBlock="$(getBlockNum)";
+ printNum "$lastBlock";
+ #echo "$lastBlock";
+ n=0;
+ while true; do
+ # update latestBlock
+ latestBlock="$(getBlockNum)";
+
+ # compare last and latestBlock
+ if [[ $latestBlock -gt $lastBlock ]]; then
+ ## true: new block
+ ## print block
+ printNum "$latestBlock";
+ #echo "$(date --iso-8601=seconds)":"$latestBlock"
+ ## update lastBlock
+ lastBlock="$latestBlock"
+ :
+ else
+ ## no new block
+ sleep "$delay"
+ fi;
+ # update counter
+ ((n++));
+ done;
+}
+#===END Declare local script functions===
+#==END Define script parameters==
+
+main "$@";
+
+# Author: Steven Baltakatei Sandoval
+# License: GPLv3+