unitproc/bkt-processArgs

   1 #!/bin/bash
   2 # Desc: Processes script arguments
   3
   4 #==BEGIN Define script parameters==
   5 #===BEGIN Define variables===
   6 :
   7 declare -ag arrayPosArgs
   8 #===END Define variables===
   9
  10 #===BEGIN Declare local script functions===
  11 yell() { echo "$0: $*" >&2; }      #o Yell, Die, Try Three-Fingered Claw technique
  12 die() { yell "$*"; exit 111; }     #o Ref/Attrib: https://stackoverflow.com/a/25515370
  13 try() { "$@" || die "cannot $*"; } #o
  14 vbm() {
  15     # Description: Prints verbose message ("vbm") to stderr if opVerbose is set to "true".
  16     # Usage: vbm "DEBUG :verbose message here"
  17     # Version 0.2.0
  18     # Input: arg1: string
  19     #        vars: opVerbose
  20     # Output: stderr
  21     # Depends: bash 5.1.16, GNU-coreutils 8.30 (echo, date)
  22
  23     if [ "$opVerbose" = "true" ]; then
  24         functionTime="$(date --iso-8601=ns)"; # Save current time in nano seconds.
  25         echo "[$functionTime]:$0:""$*" 1>&2;  # Display argument text.
  26     fi
  27
  28     # End function
  29     return 0; # Function finished.
  30 } # Displays message if opVerbose true
  31 showUsage() {
  32     # Desc: Display script usage information
  33     # Usage: showUsage
  34     # Version 0.0.2
  35     # Input: none
  36     # Output: stdout
  37     # Depends: GNU-coreutils 8.30 (cat)
  38     cat <<'EOF'
  39     USAGE:
  40         bktemp-processArgs [ options ] [FILE...]
  41
  42     OPTIONS:
  43         -h, --help
  44                 Display help information.
  45         --version
  46                 Display script version.
  47         -v, --verbose
  48                 Display debugging info.
  49         -i, --input-file
  50                 Define input file path.
  51         -I, --input-dir
  52                 Define input directory path.
  53         -o, --output-file
  54                 Define output file path.
  55         -O, --output-dir
  56                 Define output directory path.
  57         --
  58                 Indicate end of options.
  59
  60     EXAMPLE:
  61       bktemp-processArgs -o foo.txt
  62       bktemp-processArgs -o foo.txt -- some_file.txt
  63 EOF
  64 } # Display information on how to use this script.
  65 showVersion() {
  66     # Desc: Displays script version and license information.
  67     # Usage: showVersion
  68     # Version: 0.0.2
  69     # Input: scriptVersion   var containing version string
  70     # Output: stdout
  71     # Depends: vbm(), yell, GNU-coreutils 8.30
  72
  73     # Initialize function
  74     vbm "DEBUG:showVersion function called."
  75
  76     cat <<'EOF'
  77 bktemp-processArgs 1.0.0
  78 Copyright (C) 2021 Steven Baltakatei Sandoval
  79 License GPLv3: GNU GPL version 3
  80 This is free software; you are free to change and redistribute it.
  81 There is NO WARRANTY, to the extent permitted by law.
  82
  83     GNU Coreutils 8.32
  84     Copyright (C) 2020 Free Software Foundation, Inc.
  85     License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
  86     This is free software: you are free to change and redistribute it.
  87     There is NO WARRANTY, to the extent permitted by law.
  88 EOF
  89
  90     # End function
  91     vbm "DEBUG:showVersion function ended."
  92     return 0; # Function finished.
  93 } # Display script version.
  94 processArgs() {
  95     # Desc: Processes arguments provided to script.
  96     # Usage: processArgs "$@"
  97     # Version: 1.0.0
  98     # Input: "$@"          (list of arguments provided to the function)
  99     # Output: Sets following variables used by other functions:
 100     #   opVerbose            Indicates verbose mode enable status.  (ex: "true", "false")
 101     #   pathDirOut1          Path to output directory.
 102     #   pathFileOut1         Path to output file.
 103     #   pathDirIn1           Path to input directory.
 104     #   pathFileIn1          Path to input file.
 105     #   opFileOut1_overwrite Indicates whether file pathFileOut1 should be overwritten (ex: "true", "false").
 106     #   arrayPosArgs         Array of remaining positional argments
 107     # Depends:
 108     #   yell()           Displays messages to stderr.
 109     #   vbm()            Displays messsages to stderr if opVerbose set to "true".
 110     #   showUsage()      Displays usage information about parent script.
 111     #   showVersion()    Displays version about parent script.
 112     #   arrayPosArgs     Global array for storing non-option positional arguments (i.e. arguments following the `--` option).
 113     # External dependencies: bash (5.1.16), echo
 114     # Ref./Attrib.:
 115     #  [1]: Marco Aurelio (2014-05-08). "echo that outputs to stderr". https://stackoverflow.com/a/23550347
 116     #  [2]: "Handling positional parameters" (2018-05-12). https://wiki.bash-hackers.org/scripting/posparams
 117
 118     # Initialize function
 119     vbm "DEBUG:processArgs function called."
 120
 121     # Perform work
 122     while [ ! $# -eq 0 ]; do   # While number of arguments ($#) is not (!) equal to (-eq) zero (0).
 123         #yell "DEBUG:Starting processArgs while loop." # Debug stderr message. See [1].
 124         #yell "DEBUG:Provided arguments are:""$*"      # Debug stderr message. See [1].
 125         case "$1" in
 126             -h | --help) showUsage; exit 1;; # Display usage.
 127             --version) showVersion; exit 1;; # Show version
 128             -v | --verbose) opVerbose="true"; vbm "DEBUG:Verbose mode enabled.";; # Enable verbose mode. See [1].
 129             -i | --input-file) # Define input file path
 130                 if [ -f "$2" ]; then # If $2 is file that exists, set pathFileIn1 to $2, pop $2.
 131                     pathFileIn1="$2";
 132                     shift;
 133                     vbm "DEBUG:Input file pathFileIn1 set to:""$2";
 134                 else
 135                     yell "ERROR: Specified input file does not exist:""$2";
 136                     yell "Exiting.";
 137                     exit 1;
 138                 fi ;;
 139             -I | --input-dir) # Define input directory path
 140                 if [ -d "$2" ]; then # If $2 is dir that exists, set pathDirIn1 to $2, pop $2.
 141                     pathDirIn1="$2";
 142                     shift;
 143                     vbm "DEBUG:Input directory pathDirIn1 set to:""$2";
 144                 else # Display error if $2 is not a valid dir.
 145                     yell "ERROR:Specified input directory does not exist:""$2";
 146                     yell "Exiting.";
 147                     exit 1;
 148                 fi ;;
 149             -o | --output-file) # Define output file path
 150                 if [ -f "$2" ]; then # If $2 is file that exists, prompt user to continue to overwrite, set pathFileOut1 to $2, pop $2.
 151                     yell "Specified output file $2 already exists. Overwrite? (y/n):"
 152                     read -r m; case $m in
 153                                 y | Y | yes) opFileOut1_overwrite="true";;
 154                                 n | N | no) opFileOut1_overwrite="false";;
 155                                 *) yell "Invalid selection. Exiting."; exit 1;;
 156                             esac
 157                     if [ "$opFileOut1_overwrite" == "true" ]; then
 158                         pathFileOut1="$2";
 159                         shift;
 160                         vbm "DEBUG:Output file pathFileOut1 set to:""$2";
 161                     else
 162                         yell "ERORR:Exiting in order to not overwrite output file:""$pathFileOut1";
 163                         exit 1;
 164                     fi
 165                 else
 166                     pathFileOut1="$2";
 167                     shift;
 168                     vbm "DEBUG:Output file pathFileOut1 set to:""$2";
 169                 fi ;;
 170             -O | --output-dir) # Define output directory path
 171                 if [ -d "$2" ]; then # If $2 is dir that exists, set pathDirOut1 to $2, pop $2
 172                     pathDirOut1="$2";
 173                     shift;
 174                     vbm "DEBUG:Output directory pathDirOut1 set to:""$2";
 175                 else
 176                     yell "ERROR:Specified output directory is not valid:""$2";
 177                     yell "Exiting.";
 178                     exit 1;
 179                 fi ;;
 180             --) # End of all options. See [2].
 181                 shift;
 182                 for arg in "$@"; do
 183                     vbm "DEBUG:adding to arrayPosArgs:$arg";
 184                     arrayPosArgs+=("$arg");
 185                 done;
 186                 break;;
 187             -*) showUsage; yell "ERROR: Unrecognized option."; exit 1;; # Display usage
 188             *) showUsage; yell "ERROR: Unrecognized argument."; exit 1;; # Handle unrecognized options. See [1].
 189         esac
 190         shift
 191     done
 192
 193     # End function
 194     vbm "DEBUG:processArgs function ended."
 195     return  0; # Function finished.
 196 } # Evaluate script options from positional arguments (ex: $1, $2, $3, etc.).
 197
 198 #===END Declare local script functions===
 199 #==END Define script parameters==
 200
 201 #==BEGIN sample code==
 202 processArgs "$@";
 203 yell "DEBUG:Provided arguments..:""$*"
 204 yell "DEBUG:opVerbose...........:${opVerbose:-<unset>}";
 205 yell "DEBUG:pathDirOut1.........:${pathDirOut1:-<unset>}";
 206 yell "DEBUG:pathFileOut1........:${pathFileOut1:-<unset>}";
 207 yell "DEBUG:pathDirIn1..........:${pathDirIn1:-<unset>}";
 208 yell "DEBUG:pathFileIn1.........:${pathFileIn1:-<unset>}";
 209 yell "DEBUG:opFileOut1_overwrite:${opFileOut1_overwrite:-<unset>}";
 210 yell "DEBUG:arrayPosArgs........:$(if [[ -v arrayPosArgs ]]; then declare -p arrayPosArgs; else printf "<unset>"; fi )";
 211 #yell "DEBUG:arrayPosArgs........:${arrayPosArgs[*]}";
 212 #==END sample code==
 213
 214 # Author: Steven Baltaktei Sandoval
 215 # License: GPLv3+