File: dtc.sh
   1 #!/bin/sh
   2 
   3 # The MIT License (MIT)
   4 #
   5 # Copyright (c) 2026 pacman64
   6 #
   7 # Permission is hereby granted, free of charge, to any person obtaining a copy
   8 # of this software and associated documentation files (the "Software"), to deal
   9 # in the Software without restriction, including without limitation the rights
  10 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11 # copies of the Software, and to permit persons to whom the Software is
  12 # furnished to do so, subject to the following conditions:
  13 #
  14 # The above copyright notice and this permission notice shall be included in
  15 # all copies or substantial portions of the Software.
  16 #
  17 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23 # SOFTWARE.
  24 
  25 
  26 # dtc [options...]
  27 #
  28 # Date Time and Calendar shows just those, the calendar only showing the 3
  29 # `current` months around the current day.
  30 #
  31 # When variable NO_COLOR is declared and set to 1, an invert/highlight style
  32 # is used instead of colors.
  33 #
  34 # The options are, available both in single and double-dash versions
  35 #
  36 #    -h, -help    show this help message
  37 
  38 
  39 case "$1" in
  40     -h|--h|-help|--help)
  41         awk '/^# +dtc /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  42         exit 0
  43     ;;
  44 
  45     --) shift ;;
  46 
  47     -*)
  48         printf "unsupported option '%s'\n" "$1" >&2
  49         exit 1
  50     ;;
  51 esac
  52 
  53 # show the current date/time center-aligned
  54 if [ "${NO_COLOR}" = 1 ]; then
  55     printf "%20s\033[7m%s\033[0m  \033[7m%s\033[0m\n\n" \
  56         "" "$(date +'%a %b %d')" "$(date +%T)"
  57 else
  58     printf \
  59         "%20s\033[38;2;78;154;6m%s\033[0m  \033[38;2;52;101;164m%s\033[0m\n\n" \
  60         "" "$(date +'%a %b %d')" "$(date +%T)"
  61 fi
  62 # debian linux has a different `cal` app which highlights the day
  63 if [ -e /usr/bin/ncal ]; then
  64     # fix debian/ncal's weird way to highlight the current day
  65     ncal -C -3 | sed -E 's/_\x08(.+)_\x08([^ ]+)/\x1b\[7m\1\2\x1b\[0m/'
  66 else
  67     # busybox/alpine's cal doesn't support the 3-month option
  68     cal -3 2> /dev/null || cal
  69 fi