--- /dev/null
+#!/usr/bin/env bash
+
+yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
+die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
+must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
+read_stdin_psarg() {
+ # Desc: Consumes stdin and reads arguments; outputs as stdout lines
+ # Input: stdin (consumes)
+ # Input: args
+ # Output: stdout (newline delimited)
+ # Example: read_stdin_psarg "$@"
+ # Depends: GNU bash (version 5.1.16)
+ local input_stdin input_psarg output;
+
+ # Store stdin
+ if [[ -p /dev/stdin ]]; then
+ input_stdin="$(cat -)";
+ fi;
+ yell "DEBUG:$(declare -p input_stdin)";
+
+ # Store arguments
+ if [[ $# -gt 0 ]]; then
+ input_psarg="$@";
+ fi;
+ yell "DEBUG:$(declare -p input_psarg)";
+
+ # Combine as output array elements
+ ## Read in stdin
+ if [[ -n $input_stdin ]]; then
+ while read -r line; do
+ output+=("$line");
+ done < <(printf "%s\n" "$input_stdin");
+ fi;
+ ## Read in positional arguments
+ if [[ -n $input_psarg ]]; then
+ for arg in "$@"; do
+ output+=("$arg");
+ done;
+ fi;
+ yell "DEBUG:$(declare -p output)";
+
+ # Print to stdout
+ printf "%s\n" "${output[@]}";
+}; # read stdin and positional argument to stdout lines
+
+main() {
+ read_stdin_psarg "$@";
+};
+
+main "$@";
--- /dev/null
+#!/usr/bin/env bash
+# Desc: Get time difference two between date-parsable strings in seconds
+# Usage: bkdatediff [STRING] [STRING]
+# Example: bkdatediff "2023-01-10T08:36:42+00" "2023-01-10T12:30:13+00"
+# Version 0.0.1
+
+yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
+die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
+must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
+check_depends() {
+ if ! command -v date 1>/dev/random 2>&1; then die "FATAL:Missing:date"; fi;
+ return 0;
+}; # check dependencies
+show_usage() {
+ cat <<'EOF'
+ USAGE:
+ bkdatediff [STRING1] [STRING2]
+
+ STRING1, STRING2
+ `date` parsable strings. (i.e. variable STR in `date --date='$STR'`)
+
+ EXAMPLE:
+ bkdatediff "2023-01-10T08:36:42+00" "2023-01-10T12:30:13+00"
+EOF
+};
+main() {
+ local t1 t2;
+ check_depends;
+ # check args
+ if [[ ! $# -eq 2 ]]; then show_usage; die "FATAL:Wrong number of args:$#"; fi;
+
+ # get unix epoch
+ t1="$(must date --date="$1" +%s)";
+ t2="$(must date --date="$2" +%s)";
+
+ # print diff in seconds
+ printf "%s\n" "$((t2 - t1))";
+}; # main program
+
+main "$@";