#!/bin/bash
# Desc: Processes script arguments
#==BEGIN Define script parameters==
#===BEGIN Define variables===
:
declare -ag arrayPosArgs
#===END Define variables===
#===BEGIN Declare local script functions===
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:
bktemp-processArgs [ options ] [FILE...]
OPTIONS:
-h, --help
Display help information.
--version
Display script version.
-v, --verbose
Display debugging info.
-i, --input-file
Define input file path.
-I, --input-dir
Define input directory path.
-o, --output-file
Define output file path.
-O, --output-dir
Define output directory path.
--
Indicate end of options.
EXAMPLE:
bktemp-processArgs -o foo.txt
bktemp-processArgs -o foo.txt -- some_file.txt
EOF
} # Display information on how to use this script.
showVersion() {
# Desc: Displays script version and license information.
# Usage: showVersion
# Version: 0.0.2
# Input: scriptVersion var containing version string
# Output: stdout
# Depends: vbm(), yell, GNU-coreutils 8.30
# Initialize function
vbm "DEBUG:showVersion function called."
cat <<'EOF'
bktemp-processArgs 1.0.0
Copyright (C) 2021 Steven Baltakatei Sandoval
License GPLv3: GNU GPL version 3
This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
GNU Coreutils 8.32
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
EOF
# End function
vbm "DEBUG:showVersion function ended."
return 0; # Function finished.
} # Display script version.
processArgs() {
# Desc: Processes arguments provided to script.
# Usage: processArgs "$@"
# Version: 1.0.0
# Input: "$@" (list of arguments provided to the function)
# Output: Sets following variables used by other functions:
# opVerbose Indicates verbose mode enable status. (ex: "true", "false")
# pathDirOut1 Path to output directory.
# pathFileOut1 Path to output file.
# pathDirIn1 Path to input directory.
# pathFileIn1 Path to input file.
# opFileOut1_overwrite Indicates whether file pathFileOut1 should be overwritten (ex: "true", "false").
# 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].
-i | --input-file) # Define input file path
if [ -f "$2" ]; then # If $2 is file that exists, set pathFileIn1 to $2, pop $2.
pathFileIn1="$2";
shift;
vbm "DEBUG:Input file pathFileIn1 set to:""$2";
else
yell "ERROR: Specified input file does not exist:""$2";
yell "Exiting.";
exit 1;
fi ;;
-I | --input-dir) # Define input directory path
if [ -d "$2" ]; then # If $2 is dir that exists, set pathDirIn1 to $2, pop $2.
pathDirIn1="$2";
shift;
vbm "DEBUG:Input directory pathDirIn1 set to:""$2";
else # Display error if $2 is not a valid dir.
yell "ERROR:Specified input directory does not exist:""$2";
yell "Exiting.";
exit 1;
fi ;;
-o | --output-file) # Define output file path
if [ -f "$2" ]; then # If $2 is file that exists, prompt user to continue to overwrite, set pathFileOut1 to $2, pop $2.
yell "Specified output file $2 already exists. Overwrite? (y/n):"
read -r m; case $m in
y | Y | yes) opFileOut1_overwrite="true";;
n | N | no) opFileOut1_overwrite="false";;
*) yell "Invalid selection. Exiting."; exit 1;;
esac
if [ "$opFileOut1_overwrite" == "true" ]; then
pathFileOut1="$2";
shift;
vbm "DEBUG:Output file pathFileOut1 set to:""$2";
else
yell "ERORR:Exiting in order to not overwrite output file:""$pathFileOut1";
exit 1;
fi
else
pathFileOut1="$2";
shift;
vbm "DEBUG:Output file pathFileOut1 set to:""$2";
fi ;;
-O | --output-dir) # Define output directory path
if [ -d "$2" ]; then # If $2 is dir that exists, set pathDirOut1 to $2, pop $2
pathDirOut1="$2";
shift;
vbm "DEBUG:Output directory pathDirOut1 set to:""$2";
else
yell "ERROR:Specified output directory is not valid:""$2";
yell "Exiting.";
exit 1;
fi ;;
--) # End of all options. See [2].
shift;
for arg in "$@"; do
vbm "DEBUG:adding to arrayPosArgs:$arg";
arrayPosArgs+=("$arg");
done;
break;;
-*) showUsage; yell "ERROR: Unrecognized option."; exit 1;; # Display usage
*) showUsage; yell "ERROR: Unrecognized argument."; exit 1;; # Handle unrecognized options. See [1].
esac
shift
done
# End function
vbm "DEBUG:processArgs function ended."
return 0; # Function finished.
} # Evaluate script options from positional arguments (ex: $1, $2, $3, etc.).
#===END Declare local script functions===
#==END Define script parameters==
#==BEGIN sample code==
processArgs "$@";
yell "DEBUG:Provided arguments..:""$*"
yell "DEBUG:opVerbose...........:${opVerbose:-<unset>}";
yell "DEBUG:pathDirOut1.........:${pathDirOut1:-<unset>}";
yell "DEBUG:pathFileOut1........:${pathFileOut1:-<unset>}";
yell "DEBUG:pathDirIn1..........:${pathDirIn1:-<unset>}";
yell "DEBUG:pathFileIn1.........:${pathFileIn1:-<unset>}";
yell "DEBUG:opFileOut1_overwrite:${opFileOut1_overwrite:-<unset>}";
yell "DEBUG:arrayPosArgs........:$(if [[ -v arrayPosArgs ]]; then declare -p arrayPosArgs; else printf "<unset>"; fi )";
#yell "DEBUG:arrayPosArgs........:${arrayPosArgs[*]}";
#==END sample code==
# Author: Steven Baltaktei Sandoval
# License: GPLv3+