feat(sysutils):Add script to output current second (iso-8601)

diff --git a/sysutils/tick_second.sh b/sysutils/tick_second.sh
new file mode 100755 (executable)
index 0000000..e85a865
--- /dev/null
+++ b/sysutils/tick_second.sh
@@ -0,0 +1,139 @@
+#!/bin/bash
+
+# Desc: Outputs to stdout the current iso-8601 timestamp (second accuracy)
+# Usage: tick_second.sh
+# Example tick_second.sh
+
+#==BEGIN Define script parameters==
+#===BEGIN Declare 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
+declare exitFlag
+#===END Declare variables===
+
+
+#===BEGIN Declare local script functions===
+yell() { echo "$0: $*" >&2; } # Yell, Die, Try Three-Fingered Claw technique; # Ref/Attrib: https://stackoverflow.com/a/25515370
+die() { yell "$*"; exit 111; }
+try() { "$@" || die "cannot $*"; }
+checkapp() {
+    # Desc: If arg is a command, save result in assoc array 'appRollCall'
+    # Usage: checkapp arg1 arg2 arg3 ...
+    # Version: 0.1.1
+    # Input: global assoc. array 'appRollCall'
+    # Output: adds/updates key(value) to global assoc array 'appRollCall'
+    # Depends: bash 5.0.3
+    local returnState    
+
+    #===Process Args===
+    for arg in "$@"; 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 [ "$returnState" = "true" ]; then
+       return 0;
+    else
+       return 1;
+    fi;
+} # Check that app exists
+displayMissing() {
+    # Desc: Displays missing apps, files, and dirs
+    # Usage: displayMissing
+    # Version 0.1.1
+    # Input: associative arrays: appRollCall, fileRollCall, dirRollCall
+    # Output: stderr: messages indicating missing apps, file, or dirs
+    # Depends: bash 5, checkAppFileDir()
+    local missingApps value appMissing missingFiles fileMissing
+    local missingDirs dirMissing
+    
+    #==BEGIN Display errors==
+    #===BEGIN Display Missing Apps===
+    missingApps="Missing apps  :";
+    #for key in "${!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, dirsw
+main() {
+    # Desc: main program
+    # Input: var: arg1:        path
+    #        var: appRollCall  checkapp() dependency
+    #        var: exitFlag     indicates to script if exit required
+    # Output: stdout: iso-8601 date string
+    # Depends: try()
+    
+    # Validate input
+    ## Check argument count (must be 0)
+    if [[ $# -gt 0 ]]; then yell "ERROR:Too many arguments:$#"; exitFlag="true"; fi;
+    
+    ## Check Apps
+    if ! checkapp date echo; then yell "ERROR:Missing App"; exitFlag="true"; fi;
+
+    ## Report errors
+    displayMissing;
+    if [[ $exitFlag == "true" ]]; then exit 1; fi;
+
+    # Form output
+    output="$(date +%Y-%m-%dT%H:%M:%S%z)"; #iso-8601 string (e.g. 2021-05-28T19:30:57+0000)
+
+    # Write output
+    echo "$output";
+}
+
+#===END Declare local script functions===
+#==END Define script parameters==
+
+try main "$@";