| 1 | #!/usr/bin/env bash |
| 2 | # Desc: Get time difference two between date-parsable strings in seconds |
| 3 | # Usage: bkdatediff [STRING] [STRING] |
| 4 | # Example: bkdatediff "2023-01-10T08:36:42+00" "2023-01-10T12:30:13+00" |
| 5 | # Version 0.0.1 |
| 6 | |
| 7 | yell() { echo "$0: $*" >&2; } # print script path and all args to stderr |
| 8 | die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status |
| 9 | must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails |
| 10 | check_depends() { |
| 11 | if ! command -v date 1>/dev/random 2>&1; then die "FATAL:Missing:date"; fi; |
| 12 | return 0; |
| 13 | }; # check dependencies |
| 14 | show_usage() { |
| 15 | cat <<'EOF' |
| 16 | USAGE: |
| 17 | bkdatediff [STRING1] [STRING2] |
| 18 | |
| 19 | STRING1, STRING2 |
| 20 | `date` parsable strings. (i.e. variable STR in `date --date='$STR'`) |
| 21 | |
| 22 | EXAMPLE: |
| 23 | bkdatediff "2023-01-10T08:36:42+00" "2023-01-10T12:30:13+00" |
| 24 | EOF |
| 25 | }; |
| 26 | main() { |
| 27 | local t1 t2; |
| 28 | check_depends; |
| 29 | # check args |
| 30 | if [[ ! $# -eq 2 ]]; then show_usage; die "FATAL:Wrong number of args:$#"; fi; |
| 31 | |
| 32 | # get unix epoch |
| 33 | t1="$(must date --date="$1" +%s)"; |
| 34 | t2="$(must date --date="$2" +%s)"; |
| 35 | |
| 36 | # print diff in seconds |
| 37 | printf "%s\n" "$((t2 - t1))"; |
| 38 | }; # main program |
| 39 | |
| 40 | main "$@"; |