#+title: Unixfu
#+date: <2024-01-14 Sun>
#+category: linux

A bean for some useful UNIX command snippets.

* Add two hours

This could be useful for nocmig fan, to ease the hour computation of a bird contact.

#+begin_src bash
hour() {
    start=$1
    duration=$2
    IFS=":" read -r duration_hour duration_minute <<< $duration
    date -d "$start $(($duration_hour * 60 + $duration_minute)) minutes" +"%H:%M"
}
hour 17:00 5:43
#+end_src

#+RESULTS:
: 22:43

* WAV creation datetime
Here is a small snippet that demonstrates how to get the creation date-time of a WAV file with =ffprobe=

#+begin_src bash
wav_creation_date() {
        wav="$1"
        date_key="date"
        time_key="creation_time"
        for key in $date_key $time_key; do
            ffprobe "${wav}" -v quiet -select_streams v:0 -of default=noprint_wrappers=1:nokey=1 -show_entries stream=codec_type=stream_tags=creation_time:format_tags=${key}
        done
}
#+end_src

Then, on the WAV file =example.wav=:
#+begin_src bash
echo $(wav_creation_date example.wav)
#+end_src

#+begin_example
2024-01-12 18:56:28
#+end_example
