#!/usr/bin/env bash # Desc: Prints days # Depends: date (GNU Coreutils 8.32) # Version: 0.0.1 # Ref/Attrib: [1] Template:This date in recent years https://en.wikipedia.org/wiki/Template:This_date_in_recent_years # [2] Removing leading zeros before passing a shell variable to another command https://stackoverflow.com/a/11130324 declare -g yearRange; # range of years to consider yell() { echo "$0: $*" >&2; } #o Yell, Die, Try Three-Fingered Claw technique die() { yell "$*"; exit 111; } #o Ref/Attrib: https://stackoverflow.com/a/25515370 try() { "$@" || die "cannot $*"; } #o vbm() { # Description: Prints verbose message ("vbm") to stderr if opVerbose is set to "true". # Usage: vbm "DEBUG :verbose message here" # Version 0.2.0 # Input: arg1: string # vars: opVerbose # Output: stderr # Depends: bash 5.1.16, GNU-coreutils 8.30 (echo, date) if [ "$opVerbose" = "true" ]; then functionTime="$(date --iso-8601=ns)"; # Save current time in nano seconds. echo "[$functionTime]:$0:""$*" 1>&2; # Display argument text. fi # End function return 0; # Function finished. } # Displays message if opVerbose true showUsage() { # Desc: Display script usage information # Usage: showUsage # Version 0.0.2 # Input: none # Output: stdout # Depends: GNU-coreutils 8.30 (cat) cat <<'EOF' USAGE: bk_this-date-in-recent-years.sh [ options ] [str day of month] OPTIONS: -h, --help Display help information. --version Display script version. -v, --verbose Display debugging info. -r, --iso-range Specify year range (iso-8601 period), e.g. "2010/2020". By default, most recent 10 years are considered. -- Indicate end of options. EXAMPLE: bk_this_date-in-recent-years.sh "05-11" bk_this_date-in-recent-years.sh -r "1990/2020" "05-11" bk_this_date-in-recent-years.sh -r "1990/2020" -- "05-11" EOF } # Display information on how to use this script. processArgs() { # Desc: Processes arguments provided to script. # Usage: processArgs "$@" # Version: 1.0.0 # Input: "$@" (list of arguments provided to the function) # yearRange Iso date range to consider (e.g. "1999/2020"). # Output: Sets following variables used by other functions: # opVerbose Indicates verbose mode enable status. (ex: "true", "false") # opIsoRange Indicates that an iso-8601 date range is specified. (ex: "true", "false") # yearRange Iso date range to consider (e.g. "1999/2020"). # arrayPosArgs Array of remaining positional argments # Depends: # yell() Displays messages to stderr. # vbm() Displays messsages to stderr if opVerbose set to "true". # showUsage() Displays usage information about parent script. # showVersion() Displays version about parent script. # arrayPosArgs Global array for storing non-option positional arguments (i.e. arguments following the `--` option). # External dependencies: bash (5.1.16), echo # Ref./Attrib.: # [1]: Marco Aurelio (2014-05-08). "echo that outputs to stderr". https://stackoverflow.com/a/23550347 # [2]: "Handling positional parameters" (2018-05-12). https://wiki.bash-hackers.org/scripting/posparams # Initialize function vbm "DEBUG:processArgs function called." # Perform work while [ ! $# -eq 0 ]; do # While number of arguments ($#) is not (!) equal to (-eq) zero (0). #yell "DEBUG:Starting processArgs while loop." # Debug stderr message. See [1]. #yell "DEBUG:Provided arguments are:""$*" # Debug stderr message. See [1]. case "$1" in -h | --help) showUsage; exit 1;; # Display usage. --version) showVersion; exit 1;; # Show version -v | --verbose) opVerbose="true"; vbm "DEBUG:Verbose mode enabled.";; # Enable verbose mode. See [1]. -r | --iso-range) opIsoRange="true"; vbm "DEBUG:Accepting iso-8601 year range."; # Accept iso-8601 year range. shift; yearRange="$1";; --) # End of all options. See [2]. shift; for arg in "$@"; do vbm "DEBUG:adding to arrayPosArgs:$arg"; arrayPosArgs+=("$arg"); done; break;; -*) showUsage; yell "ERROR: Unrecognized option."; exit 1;; # Display usage *) for arg in "$@"; do vbm "DEBUG:adding to arrayPosArgs:$arg"; arrayPosArgs+=("$arg"); done; break;; esac shift done # End function vbm "DEBUG:processArgs function ended." return 0; # Function finished. } # Evaluate script options from positional arguments (ex: $1, $2, $3, etc.). validatePosArgs() { # Input: arrayPosArgs array with positional arguments # opVerbose bool indicates to vbm() to display verbose text # opIsoRange bool indicates to use a user-provided year range # yearRange str iso-8601 year range provided by -r, --iso-range option # Validate year $range re='^[0-9]+/[0-9]+$'; # Simply check (int)/(int). Don't address Gregorian Calendar here. if [[ $opIsoRange == "true" && ! "$yearRange" =~ $re ]] ; then showUsage; yell "ERROR:Not a valid date range (e.g. 2010/2022):$yearRange"; return 1; fi; return 0; }; # Validate arguments main() { # Input: arrayPosArgs array with positional arguments # opVerbose bool indicates to vbm() to display verbose text # opIsoRange bool indicates to use a user-provided year range # yearRange str iso-8601 year range provided by -r, --iso-range option # Output: stdout: dates with days of the week (newline delimited) # Depends: date (GNU Coreutils 8.32) # Depends: processArgs(), yell(), vbm(), showUsage(), showVersion(), validatePosArgs() local dom yc ymin ymax; # Check input processArgs "$@"; if ! validatePosArgs; then die "FATAL:Invalid positional arguments:$(declare -p arrayPosArgs)"; fi; # Define year range if [[ ! $opIsoRange == "true" ]]; then ## Default: Most recent 10 years yc="10"; # count of years to consider ymax="$(date +%Y)"; # highest year to consider ymin="$((ymax - yc))"; # earliest year to consider else ## Provided via -r,--iso-range option ymin="$(echo "$yearRange" | cut -d'/' -f1)"; ymin="$((10#$ymin))"; # strip leading zeroes. See [2] ymax="$(echo "$yearRange" | cut -d'/' -f2)"; # See [2] ymax="$((10#$ymax))"; # strip leading zeroes. See [2] yc="$((ymax - ymin + 1))"; fi; # yell "DEBUG:ymin:$ymin"; # yell "DEBUG:ymax:$ymax"; # yell "DEBUG:yc :$yc"; # Check year range if ! [[ $(( ymax - ymin )) -ge 0 ]]; then die "FATAL:Invalid year range:$yearRange"; fi; # Print Output ## Get day of month (first positional argument) dom="${arrayPosArgs[0]}"; for (( year = ymin; year <= ymax; year++ )); do dstr="$year-$dom"; date +%Y-%m-%d\ %A --date="$dstr"; # printf "DEBUG:dom :%s\n" "$dom"; # printf "DEBUG:ymax:%s\n" "$ymax"; # printf "DEBUG:ymin:%s\n" "$ymin"; # printf "DEBUG:year:%s\n" "$year"; # printf "DEBUG:dstr:%s\n" "$dstr"; done; }; # main program main "$@"; # Author: Steven Baltakatei Sandoval # License: GPLv3+ # Ref/Attrib (depends) # date (GNU coreutils) 8.32 # Copyright (C) 2020 Free Software Foundation, Inc. # License GPLv3+: GNU GPL version 3 or later . # This is free software: you are free to change and redistribute it. # There is NO WARRANTY, to the extent permitted by law. # Written by David MacKenzie.