amend! first steps with command line args

first steps with command line args

shopts.sh

@@ -0,0 +1,63 @@
+#!/bin/bash
+# ex33.sh: Exercising getopts and OPTIND
+#          Script modified 10/09/03 at the suggestion of Bill Gradwohl.
+
+
+# Here we observe how 'getopts' processes command-line arguments to script.
+# The arguments are parsed as "options" (flags) and associated arguments.
+
+# Try invoking this script with:
+#   'scriptname -mn'
+#   'scriptname -oq qOption' (qOption can be some arbitrary string.)
+#   'scriptname -qXXX -r'
+#
+#   'scriptname -qr'
+#+      - Unexpected result, takes "r" as the argument to option "q"
+#   'scriptname -q -r' 
+#+      - Unexpected result, same as above
+#   'scriptname -mnop -mnop'  - Unexpected result
+#   (OPTIND is unreliable at stating where an option came from.)
+#
+#  If an option expects an argument ("flag:"), then it will grab
+#+ whatever is next on the command-line.
+
+NO_ARGS=0 
+E_OPTERROR=85
+
+if [ $# -eq "$NO_ARGS" ]    # Script invoked with no command-line args?
+then
+  echo "Usage: `basename $0` options (-mnopqrs)"
+  exit $E_OPTERROR          # Exit and explain usage.
+                            # Usage: scriptname -options
+                            # Note: dash (-) necessary
+fi  
+
+
+while getopts ":mnopq:rs" Option
+do
+  case $Option in
+    m     ) echo "$OPTIND -$Option ($OPTARG)";;
+    n | o ) echo "$OPTIND -$Option ($OPTARG)";;
+    p     ) echo "$OPTIND -$Option ($OPTARG)";;
+    q     ) echo "$OPTIND -$Option ($OPTARG)";;
+    #  Note that option 'q' must have an associated argument,
+    #+ otherwise it falls through to the default.
+    r | s ) echo "$OPTIND -$Option ($OPTARG)";;
+    *     ) echo "Unimplemented option chosen.";;   # Default.
+  esac
+done
+
+shift $(($OPTIND - 1))
+echo "Rest $@"
+
+#  Decrements the argument pointer so it points to next argument.
+#  $1 now references the first non-option item supplied on the command-line
+#+ if one exists.
+
+exit $?
+
+#   As Bill Gradwohl states,
+#  "The getopts mechanism allows one to specify:  scriptname -mnop -mnop
+#+  but there is no reliable way to differentiate what came
+#+ from where by using OPTIND."
+#  There are, however, workarounds.

test/main.inc

@@ -0,0 +1,8 @@
+
+INC=include
+HOST_NAME=$(hostname)
+
+testfunc() {
+    echo "testfunc() works!"
+}
+ 

test/main.sh

@@ -0,0 +1,88 @@
+#!/usr/bin/env bash
+
+show_help() {
+    echo "usage: $0 options"
+    echo "       -a, --auto      start nightly backup"
+    echo "       -l, --list      list archives" 
+    echo '       -c, --content <archive> '
+    echo "                       show contents of archive"
+    echo '       -r, --restore <archive> <file(s)> ' 
+    echo "                       restore files from archive to pwd"
+    echo "       -h, -?. --help  show this help"
+}
+
+echo "    ### main.sh"
+
+# Initialize all the option variables.
+# This ensures we are not contaminated by variables from the environment.
+file=
+archive=
+
+while :; do
+    case $1 in
+        -h|-\?|--help)
+            show_help    # Display a usage synopsis.
+            exit 0
+            ;;
+        -a|--auto) 
+            shift 
+            . $HERE/$HOST_NAME.sh "$@" >$LOGF 2>&1
+            break # exit kehrt nicht zu run.sh zurück
+            ;;
+        -l|--list)
+            . $HERE/$HOST_NAME.sh -l
+            break;
+            ;;
+        -c|--content)
+            if [ "$2" ]; then
+                echo "not yet implemented"
+                #. $HERE/$HOST_NAME.sh -c $2
+            else
+                echo 'ERROR: "--content" requires a non-empty option argument.'
+            fi
+            break
+            ;;
+        -r|--restore)
+            if [ "$2" ]; then
+                echo "not yet implemented"
+                archive=$2
+                shift
+                #. $HERE/$HOST_NAME.sh -r $archive $@
+            else
+                echo 'ERROR: "--restore" requires a non-empty option argument.'
+            fi
+            break
+            ;;
+
+    # --- example -> https://mywiki.wooledge.org/BashFAQ/035
+        -f|--file)       # Takes an option argument; ensure it has been specified.
+            if [ "$2" ]; then
+                file=$2
+                shift
+            else
+                die 'ERROR: "--file" requires a non-empty option argument.'
+            fi
+            ;;
+        --file=?*)
+            file=${1#*=} # Delete everything up to "=" and assign the remainder.
+            ;;
+        --file=)         # Handle the case of an empty --file=
+            die 'ERROR: "--file" requires a non-empty option argument.'
+            ;;
+        --)              # End of all options.
+            shift
+            break
+            ;;
+        -?*)
+            echo "WARN: Unknown option (ignored): $1" 
+            echo
+            show_help
+            exit
+            ;;
+        *)               # Default case: No more options, so break out of the loop.
+            break
+    esac
+
+    shift
+done
+

test/nathan.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+echo "        *** nathan.sh"
+for i in "$@"; do echo "param: $i"; done
+
+echo "        include=$INC"
+echo "        host=$HOST_NAME"     
+testfunc                                                                                                                
+echo "        *** nathan.sh end"
+

test/run.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+HERE=$(dirname "$0")
+. $HERE/main.inc
+
+LOGF=$HERE/t1.log
+
+echo "--- run.sh"
+
+. $HERE/main.sh "$@" 
+
+echo "--- run.sh end"

test/t1.log

@@ -0,0 +1,10 @@
+testfunc() works!
+    ### main.sh
+usage: ./run.sh options
+       -a, --auto      start nightly backup
+       -l, --list      list archives
+       -c, --content <archive> 
+                       show contents of archive
+       -r, --restore <archive> <file(s)> 
+                       restore files from archive to pwd
+       -h, -?. --help  show this help