user/bk_this-date-in-recent-years.sh

   1 #!/usr/bin/env bash
   2 # Desc: Prints days
   3 # Depends: date (GNU Coreutils 8.32)
   4 # Version: 0.0.1
   5 # Ref/Attrib: [1] Template:This date in recent years https://en.wikipedia.org/wiki/Template:This_date_in_recent_years
   6 #             [2] Removing leading zeros before passing a shell variable to another command https://stackoverflow.com/a/11130324
   7
   8 declare -g yearRange;  # range of years to consider
   9
  10 yell() { echo "$0: $*" >&2; }      #o Yell, Die, Try Three-Fingered Claw technique
  11 die() { yell "$*"; exit 111; }     #o Ref/Attrib: https://stackoverflow.com/a/25515370
  12 try() { "$@" || die "cannot $*"; } #o
  13 vbm() {
  14     # Description: Prints verbose message ("vbm") to stderr if opVerbose is set to "true".
  15     # Usage: vbm "DEBUG :verbose message here"
  16     # Version 0.2.0
  17     # Input: arg1: string
  18     #        vars: opVerbose
  19     # Output: stderr
  20     # Depends: bash 5.1.16, GNU-coreutils 8.30 (echo, date)
  21
  22     if [ "$opVerbose" = "true" ]; then
  23         functionTime="$(date --iso-8601=ns)"; # Save current time in nano seconds.
  24         echo "[$functionTime]:$0:""$*" 1>&2;  # Display argument text.
  25     fi
  26
  27     # End function
  28     return 0; # Function finished.
  29 } # Displays message if opVerbose true
  30 showUsage() {
  31     # Desc: Display script usage information
  32     # Usage: showUsage
  33     # Version 0.0.2
  34     # Input: none
  35     # Output: stdout
  36     # Depends: GNU-coreutils 8.30 (cat)
  37     cat <<'EOF'
  38     USAGE:
  39         bk_this-date-in-recent-years.sh [ options ] [str day of month]
  40
  41     OPTIONS:
  42         -h, --help
  43                 Display help information.
  44         --version
  45                 Display script version.
  46         -v, --verbose
  47                 Display debugging info.
  48         -r, --iso-range
  49                 Specify year range (iso-8601 period), e.g.
  50                 "2010/2020". By default, most recent 10
  51                 years are considered.
  52         --
  53                 Indicate end of options.
  54
  55     EXAMPLE:
  56       bk_this_date-in-recent-years.sh "05-11"
  57       bk_this_date-in-recent-years.sh -r "1990/2020" "05-11"
  58       bk_this_date-in-recent-years.sh -r "1990/2020" -- "05-11"
  59 EOF
  60 } # Display information on how to use this script.
  61 processArgs() {
  62     # Desc: Processes arguments provided to script.
  63     # Usage: processArgs "$@"
  64     # Version: 1.0.0
  65     # Input: "$@"          (list of arguments provided to the function)
  66     #   yearRange            Iso date range to consider (e.g. "1999/2020").
  67     # Output: Sets following variables used by other functions:
  68     #   opVerbose            Indicates verbose mode enable status.  (ex: "true", "false")
  69     #   opIsoRange           Indicates that an iso-8601 date range is specified. (ex: "true", "false")
  70     #   yearRange            Iso date range to consider (e.g. "1999/2020").
  71     #   arrayPosArgs         Array of remaining positional argments
  72     # Depends:
  73     #   yell()           Displays messages to stderr.
  74     #   vbm()            Displays messsages to stderr if opVerbose set to "true".
  75     #   showUsage()      Displays usage information about parent script.
  76     #   showVersion()    Displays version about parent script.
  77     #   arrayPosArgs     Global array for storing non-option positional arguments (i.e. arguments following the `--` option).
  78     # External dependencies: bash (5.1.16), echo
  79     # Ref./Attrib.:
  80     #  [1]: Marco Aurelio (2014-05-08). "echo that outputs to stderr". https://stackoverflow.com/a/23550347
  81     #  [2]: "Handling positional parameters" (2018-05-12). https://wiki.bash-hackers.org/scripting/posparams
  82
  83     # Initialize function
  84     vbm "DEBUG:processArgs function called."
  85
  86     # Perform work
  87     while [ ! $# -eq 0 ]; do   # While number of arguments ($#) is not (!) equal to (-eq) zero (0).
  88         #yell "DEBUG:Starting processArgs while loop." # Debug stderr message. See [1].
  89         #yell "DEBUG:Provided arguments are:""$*"      # Debug stderr message. See [1].
  90         case "$1" in
  91             -h | --help) showUsage; exit 1;; # Display usage.
  92             --version) showVersion; exit 1;; # Show version
  93             -v | --verbose) opVerbose="true"; vbm "DEBUG:Verbose mode enabled.";; # Enable verbose mode. See [1].
  94             -r | --iso-range)
  95                 opIsoRange="true"; vbm "DEBUG:Accepting iso-8601 year range."; # Accept iso-8601 year range.
  96                 shift;
  97                 yearRange="$1";;
  98             --) # End of all options. See [2].
  99                 shift;
 100                 for arg in "$@"; do
 101                     vbm "DEBUG:adding to arrayPosArgs:$arg";
 102                     arrayPosArgs+=("$arg");
 103                 done;
 104                 break;;
 105             -*) showUsage; yell "ERROR: Unrecognized option."; exit 1;; # Display usage
 106             *) for arg in "$@"; do
 107                    vbm "DEBUG:adding to arrayPosArgs:$arg";
 108                    arrayPosArgs+=("$arg");
 109                done;
 110                break;;
 111         esac
 112         shift
 113     done
 114
 115     # End function
 116     vbm "DEBUG:processArgs function ended."
 117     return  0; # Function finished.
 118 } # Evaluate script options from positional arguments (ex: $1, $2, $3, etc.).
 119 validatePosArgs() {
 120     # Input: arrayPosArgs  array with positional arguments
 121     #        opVerbose    bool indicates to vbm() to display verbose text
 122     #        opIsoRange   bool indicates to use a user-provided year range
 123     #        yearRange    str  iso-8601 year range provided by -r, --iso-range option
 124
 125     # Validate year $range
 126     re='^[0-9]+/[0-9]+$'; # Simply check (int)/(int). Don't address Gregorian Calendar here.
 127     if [[ $opIsoRange == "true" && ! "$yearRange" =~ $re ]] ; then
 128         showUsage;
 129         yell "ERROR:Not a valid date range (e.g. 2010/2022):$yearRange";
 130         return 1;
 131     fi;
 132     return 0;
 133 }; # Validate arguments
 134 main() {
 135     # Input: arrayPosArgs  array with positional arguments
 136     #        opVerbose    bool indicates to vbm() to display verbose text
 137     #        opIsoRange   bool indicates to use a user-provided year range
 138     #        yearRange    str  iso-8601 year range provided by -r, --iso-range option
 139     # Output: stdout: dates with days of the week (newline delimited)
 140     # Depends: date (GNU Coreutils 8.32)
 141     # Depends: processArgs(), yell(), vbm(), showUsage(), showVersion(), validatePosArgs()
 142     local dom yc ymin ymax;
 143
 144     # Check input
 145     processArgs "$@";
 146     if ! validatePosArgs; then
 147         die "FATAL:Invalid positional arguments:$(declare -p arrayPosArgs)";
 148     fi;
 149
 150     # Define year range
 151     if [[ ! $opIsoRange == "true" ]]; then
 152         ## Default: Most recent 10 years
 153         yc="10";                 # count of years to consider
 154         ymax="$(date +%Y)";      # highest year to consider
 155         ymin="$((ymax - yc))"; # earliest year to consider
 156     else
 157         ## Provided via -r,--iso-range option
 158         ymin="$(echo "$yearRange" | cut -d'/' -f1)";
 159         ymin="$((10#$ymin))"; # strip leading zeroes. See [2]
 160         ymax="$(echo "$yearRange" | cut -d'/' -f2)"; # See [2]
 161         ymax="$((10#$ymax))"; # strip leading zeroes. See [2]
 162         yc="$((ymax - ymin + 1))";
 163     fi;
 164     # yell "DEBUG:ymin:$ymin";
 165     # yell "DEBUG:ymax:$ymax";
 166     # yell "DEBUG:yc  :$yc";
 167
 168     # Check year range
 169     if ! [[ $(( ymax - ymin )) -ge 0 ]]; then die "FATAL:Invalid year range:$yearRange"; fi;
 170
 171     # Print Output
 172     ## Get day of month (first positional argument)
 173     dom="${arrayPosArgs[0]}";
 174     for (( year = ymin; year <= ymax; year++ )); do
 175         dstr="$year-$dom";
 176         date +%Y-%m-%d\ %A --date="$dstr";
 177         # printf "DEBUG:dom :%s\n" "$dom";
 178         # printf "DEBUG:ymax:%s\n" "$ymax";
 179         # printf "DEBUG:ymin:%s\n" "$ymin";
 180         # printf "DEBUG:year:%s\n" "$year";
 181         # printf "DEBUG:dstr:%s\n" "$dstr";
 182     done;
 183 }; # main program
 184
 185 main "$@";
 186
 187
 188
 189 # Author: Steven Baltakatei Sandoval
 190 # License: GPLv3+
 191
 192 # Ref/Attrib (depends)
 193
 194     # date (GNU coreutils) 8.32
 195     # Copyright (C) 2020 Free Software Foundation, Inc.
 196     # License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
 197     # This is free software: you are free to change and redistribute it.
 198     # There is NO WARRANTY, to the extent permitted by law.
 199
 200     # Written by David MacKenzie.