add prompt and decide function

bsf.sh

@@ -1,23 +1,28 @@
 #!/bin/bash
 
-##### bash framework
+# BASH FRAMEWORK
-# some useful bash functions to make things easier
+# Some useful bash functions to make things easier.
+#
+# Copyright (C) 2017-2018 willipink.eu
+# Author Moritz Münch moritzmuench@mailbox.org
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
 
-## use printf for safety purposes
-# http://www.etalabs.net/sh_tricks.html
-# @param string what to say
-say ()    { printf %s\\n "$*" ; }
-sayn ()   { printf %s "$*" ; }
 
-## check if user is root
-root ()   { [[ "$EUID" -eq 0 ]] ; }
 
-## check if last call had errors
+# VARIABLES
-## if yes print generic error message and exit
+## COLORS (use ANSI escape codes)
-ok() { [[ "$?" -ne 0 ]] && echo "ERROR, aborting." && exit 1; }
-
-## colors
-# use ANSI escape codes
 normal () { printf '\033[0m'    ; }
 red ()	  { printf '\033[0;31m' ; }
 green ()  { printf '\033[0;32m' ; }
@@ -37,9 +42,101 @@ lpurple (){ printf '\033[1;35m' ; }
 lcyan ()  { printf '\033[1;36m' ; }
 white ()  { printf '\033[1;37m' ; }
 
+
+
+# FUNCTIONS
+# Print somethong to STDOUT. Use printf for safety purposes, see http://www.etalabs.net/sh_tricks.html
+# @param string what to say
+say () {
+    printf %s\\n "$*"
+}
+
+
+# Print to Stdout. Do not finish with a linebreak
+sayn () {
+    printf %s "$*"
+}
+
+
+# check if user is root
+# @return true if user is root, else false
+is_root () {
+    if [[ "$EUID" -eq 0 ]]; then
+        return true
+    else
+        return false
+    fi
+}
+
+# run a command as root user, if not root, or root password was not yet entered prompt for it
+# @param *args: arbitrary command to execute as root
+root () {
+    if [[ "$EUID" -eq 0 ]]; then
+        $*
+    elif [[ -z $PW ]]; then
+        echo -n "root password: "
+        read -s pw
+        echo
+        export "PW=$pw"
+        unset pw
+    fi
+    su -c "$*" <<< "$PW"
+}
+
+# ask a question and get the answer
+# [@param 1 string]: If this is "silent" the user cannot see its keyboard input (good for passwords)
+# @param 2 string: the prompt text
+# @return answer: the user input
+_prompt() {
+    if [[ "$1" == "silent" ]]; then
+        say "$2"
+        read -rs answer
+    else
+        say "$1"
+        read -r answer
+    fi
+}
+# example _prompt
+# _prompt "What is your answer?"
+# say "You responded $answer"
+
+
+# ask for a yes or no decision
+# @param 1: the question that should be answered with yes or no
+# @return: 0 if question was answered with yes, else 0
+_decide() {
+    until [[ $confirm =~ ^[ynYN]$ ]]; do
+        say "$1"
+        sayn "y(es) or n(o)?: "
+        read -r confirm
+    done
+    if [[ $confirm =~ [yY] ]]; then
+        return 0
+    else
+        return 1
+    fi
+}
+# example _decide
+# if _decide "Time to decide, yes or no?"; then
+#     echo "You decides yes!"
+# else
+#     echo "You devided no!"
+# fi
+
+# Check if last call had errors. If so, print error message and exit.
+ok() {
+    if [[ "$?" -ne 0 ]]; then
+        say "ERROR, aborting."
+        exit 1
+    fi
+}
+
+
 # quick styler, usage "style *color*"
-style() {
+sayc() {
     [[ "$1" == "" ]] && orange || $1
     sayn " ::: "
+    shift
+    say "$*"
     normal
 }