unitproc/bktemp-processArgs

   1 #!/bin/bash
   2 # Desc: Processes script arguments
   3
   4 #==BEGIN Define script parameters==
   5 #===BEGIN Define variables===
   6 :
   7 #===END Define variables===
   8
   9 #===BEGIN Declare local script functions===
  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 $*"; } #o
  13 vbm() {
  14     # Description: Prints verbose message ("vbm") to stderr if opVerbose is set to "true".
  15     # Usage: vbm "DEBUG :verbose message here"
  16     # Version 0.2.0
  17     # Input: arg1: string
  18     #        vars: opVerbose
  19     # Output: stderr
  20     # Depends: bash 5.0.3, GNU-coreutils 8.30 (echo, date)
  21
  22     if [ "$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 0.0.1
  34     # Input: none
  35     # Output: stdout
  36     # Depends: GNU-coreutils 8.30 (cat)
  37     cat <<'EOF'
  38     USAGE:
  39         bktemp-processArgs [ options ] [FILE...]
  40
  41     OPTIONS:
  42         -h, --help
  43                 Display help information.
  44         --version
  45                 Display script version.
  46         -v, --verbose
  47                 Display debugging info.
  48         -i, --input-file
  49                 Define input file path.
  50         -I, --input-dir
  51                 Define input directory path.
  52         -o, --output-file
  53                 Define output file path
  54         -O, --output-dir
  55                 Define output directory path
  56
  57     EXAMPLE:
  58       bktemp-processArgs -o foo.txt
  59 EOF
  60 } # Display information on how to use this script.
  61 showVersion() {
  62     # Desc: Displays script version and license information.
  63     # Usage: showVersion
  64     # Version: 0.0.1
  65     # Input: scriptVersion   var containing version string
  66     # Output: stdout
  67     # Depends: vbm(), yell, GNU-coreutils 8.30
  68
  69     # Initialize function
  70     vbm "DEBUG:showVersion function called."
  71
  72     cat <<'EOF'
  73 bktemp-processArgs 0.0.1
  74 Copyright (C) 2021 Steven Baltakatei Sandoval
  75 License GPLv3: GNU GPL version 3
  76 This is free software; you are free to change and redistribute it.
  77 There is NO WARRANTY, to the extent permitted by law.
  78
  79     GNU Coreutils 8.30
  80     Copyright (C) 2018 Free Software Foundation, Inc.
  81     License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
  82     This is free software: you are free to change and redistribute it.
  83     There is NO WARRANTY, to the extent permitted by law.
  84 EOF
  85
  86     # End function
  87     vbm "DEBUG:showVersion function ended."
  88     return 0; # Function finished.
  89 } # Display script version.
  90 processArgs() {
  91     # Desc: Processes arguments provided to script.
  92     # Usage: processArgs "$@"
  93     # Version: 0.0.1
  94     # Input: "$@"          (list of arguments provided to the function)
  95     # Output: Sets following variables used by other functions:
  96     #   opVerbose            Indicates verbose mode enable status.  (ex: "true", "false")
  97     #   pathDirOut1          Path to output directory.
  98     #   pathFileOut1         Path to output file.
  99     #   pathDirIn1           Path to input directory.
 100     #   pathFileIn1          Path to input file.
 101     #   opFileOut1_overwrite Indicates whether file pathFileOut1 should be overwritten (ex: "true", "false')
 102     # Depends:
 103     #   yell()           Displays messages to stderr.
 104     #   vbm()            Displays messsages to stderr if opVerbose set to "true".
 105     #   showUsage()      Displays usage information about parent script
 106     #   showVersion()    Displays version about parent script
 107     # External dependencies: bash (5.0.3), echo
 108     # Ref./Attrib.:
 109     #  [1]: Marco Aurelio (2014-05-08). "echo that outputs to stderr". https://stackoverflow.com/a/23550347
 110
 111     # Initialize function
 112     vbm "DEBUG:processArgs function called."
 113
 114     # Perform work
 115     while [ ! $# -eq 0 ]; do   # While number of arguments ($#) is not (!) equal to (-eq) zero (0).
 116         #yell "DEBUG:Starting processArgs while loop." # Debug stderr message. See [1].
 117         #yell "DEBUG:Provided arguments are:""$*"      # Debug stderr message. See [1].
 118         case "$1" in
 119             -h | --help) showUsage; exit 1;; # Display usage.
 120             --version) showVersion; exit 1;; # Show version
 121             -v | --verbose) opVerbose="true"; vbm "DEBUG:Verbose mode enabled.";; # Enable verbose mode. See [1].
 122             -i | --input-file) # Define input file path
 123                 if [ -f "$2" ]; then # If $2 is file that exists, set pathFileIn1 to $2, pop $2.
 124                     pathFileIn1="$2";
 125                     shift;
 126                     vbm "DEBUG:Input file pathFileIn1 set to:""$2";
 127                 else
 128                     yell "ERROR: Specified input file does not exist:""$2";
 129                     yell "Exiting.";
 130                     exit 1;
 131                 fi ;;
 132             -I | --input-dir) # Define input directory path
 133                 if [ -d "$2" ]; then # If $2 is dir that exists, set pathDirIn1 to $2, pop $2.
 134                     pathDirIn1="$2";
 135                     shift;
 136                     vbm "DEBUG:Input directory pathDirIn1 set to:""$2";
 137                 else # Display error if $2 is not a valid dir.
 138                     yell "ERROR:Specified input directory does not exist:""$2";
 139                     yell "Exiting.";
 140                     exit 1;
 141                 fi ;;
 142             -o | --output-file) # Define output file path
 143                 if [ -f "$2" ]; then # If $2 is file that exists, prompt user to continue to overwrite, set pathFileOut1 to $2, pop $2.
 144                     yell "Specified output file $2 already exists. Overwrite? (y/n):"
 145                     read -r m; case $m in
 146                                 y | Y | yes) opFileOut1_overwrite="true";;
 147                                 n | N | no) opFileOut1_overwrite="false";;
 148                                 *) yell "Invalid selection. Exiting."; exit 1;;
 149                             esac
 150                     if [ "$opFileOut1_overwrite" == "true" ]; then
 151                         pathFileOut1="$2";
 152                         shift;
 153                         vbm "DEBUG:Output file pathFileOut1 set to:""$2";
 154                     else
 155                         yell "ERORR:Exiting in order to not overwrite output file:""$pathFileOut1";
 156                         exit 1;
 157                     fi
 158                 else
 159                     pathFileOut1="$2";
 160                     shift;
 161                     vbm "DEBUG:Output file pathFileOut1 set to:""$2";
 162                 fi ;;
 163             -O | --output-dir) # Define output directory path
 164                 if [ -d "$2" ]; then # If $2 is dir that exists, set pathDirOut1 to $2, pop $2
 165                     pathDirOut1="$2";
 166                     shift;
 167                     vbm "DEBUG:Output directory pathDirOut1 set to:""$2";
 168                 else
 169                     yell "ERROR:Specified output directory is not valid:""$2";
 170                     yell "Exiting.";
 171                     exit 1;
 172                 fi ;;
 173             *) yell "ERROR: Unrecognized argument."; exit 1;; # Handle unrecognized options. See [1].
 174         esac
 175         shift
 176     done
 177
 178     # End function
 179     vbm "DEBUG:processArgs function ended."
 180     return  0; # Function finished.
 181 } # Evaluate script options from positional arguments (ex: $1, $2, $3, etc.).
 182
 183 #===END Declare local script functions===
 184 #==END Define script parameters==
 185
 186 #==BEGIN sample code==
 187 processArgs "$@";
 188 yell "DEBUG:Provided arguments..:""$*"
 189 yell "DEBUG:opVerbose...........:$opVerbose";
 190 yell "DEBUG:pathDirOut1.........:$pathDirOut1";
 191 yell "DEBUG:pathFileOut1........:$pathFileOut1";
 192 yell "DEBUG:pathDirIn1..........:$pathDirIn1";
 193 yell "DEBUG:pathFileIn1.........:$pathFileIn1";
 194 yell "DEBUG:opFileOut1_overwrite:$opFileOut1_overwrite";
 195 #==END sample code==
 196
 197 # Author: Steven Baltaktei Sandoval
 198 # License: GPLv3+