grml-lock: drop gdialog usage and don't wrap text in zenity

gdialog is a compatibility wrapper around zenity and encourages
users to switch to usage of zenity, let's follow this recommendation.

Older zenity versions (like 3.14.0) had a different wrapping
behavior than more current versions (like 3.30.0). To avoid
small dialogs with only one or two words on each line (which
is ugly and close to unreadable) let's avoid wrapping text.

While at it fix some minor issues reported by shellcheck.

This work was funded by Grml-Forensic.

diff --git a/usr_bin/grml-lock b/usr_bin/grml-lock
index ac05958..27ba082 100755 (executable)
--- a/usr_bin/grml-lock
+++ b/usr_bin/grml-lock
@@ -6,7 +6,7 @@
 # License:       This file is licensed under the GPL v2.
 ################################################################################
 
-PN="$(basename $0)"
+PN="$(basename "$0")"
 
 [ -n "$USER" ] || USER=grml
 
@@ -32,15 +32,22 @@ PWD_TEXT2="Retype new password:"
 DIALOG='dialog'
 PWD_CMD="dialog --stdout --title $PN --passwordbox"
 
-# only if using X and gdialog + zenity are available use graphical frontend
-if [ -n "$DISPLAY" ] && [ -x "$(which gdialog)" ] && [ -x "$(which zenity)" ] ; then
-  DIALOG='gdialog'
+GUI=false
+# only when using X and zenity is available use graphical frontend
+if [ -n "${DISPLAY}" ] && [ -x "$(command -v zenity)" ] ; then
+  DIALOG='zenity'
   PWD_CMD="zenity --title $PN --entry --hide-text"
+  GUI=true
 fi
 
 if ! [ -r /etc/grml_version ] ; then
-  $DIALOG --title "$PN" --msgbox "Warning: this system does not look like a Grml (based) system
-and therefore might not work as intended." 7 70
+  if [ "${GUI}" = true ] ; then
+    $DIALOG --no-wrap --title "$PN" --warning --text "Warning: this system does not look like a Grml (based) system,\n
+    and therefore might not work as intended."
+  else
+    $DIALOG --title "$PN" --msgbox "Warning: this system does not look like a Grml (based) system
+    and therefore might not work as intended." 7 70
+  fi
 fi
 
 lock_desktop() {
@@ -61,7 +68,7 @@ is_passwd_set() {
 }
 
 set_passwd() {
-  if [ "$DIALOG" = "gdialog" ] ; then
+  if [ "${GUI}" = true ] ; then
     PASSWD1="$($PWD_CMD --text="$PWD_TEXT1")"
     PASSWD2="$($PWD_CMD --text="$PWD_TEXT2")"
   else
@@ -70,20 +77,29 @@ set_passwd() {
   fi
 
   if [ -z "$PASSWD1" ] ; then
-    $DIALOG --title "$PN" --msgbox "Error retrieving password. Exiting." 0 0
+    if [ -n "${GUI}" ] ; then
+      $DIALOG --title "$PN" --error --text "Error retrieving password. Exiting."
+    else
+      $DIALOG --title "$PN" --msgbox "Error retrieving password. Exiting." 0 0
+    fi
     exit 1
   fi
+
   if [ "$PASSWD1" = "$PASSWD2" ] ; then
     echo "$USER:$PASSWD2" | sudo chpasswd
   else
-    $DIALOG --title "$PN" --msgbox "Error: passwords do not match. Exiting." 0 0
+    if [ "${GUI}" = true ] ; then
+      $DIALOG --no-wrap --title "$PN" --error --text "Error: passwords do not match.\nExiting."
+    else
+      $DIALOG --title "$PN" --msgbox "Error: passwords do not match. Exiting." 0 0
+    fi
     exit 1
   fi
 }
 
 askpwd() {
-  if [ "$DIALOG" = "gdialog" ] ; then
-    zenity --title="$PN" --question --cancel-label='Exit' --ok-label='Set password' --text="User $USER has no password set yet. Without a password you will not be able to log in again. Set password for user $USER?"
+  if [ "${GUI}" = true ] ; then
+    $DIALOG --no-wrap --title="$PN" --question --cancel-label='Exit' --ok-label='Set password' --text="User $USER has no password set yet.\nWithout a password you will not be able to log in again.\nSet password for user $USER?"
     RC=$?
   else
     $DIALOG --title "$PN" --no-label Exit --yes-label Continue --yesno "User $USER has no password set yet. Without a password you will not be able to log in again. Set password for user $USER?" 0 0
@@ -100,8 +116,11 @@ askpwd() {
 if ! isgrmlcd ; then
   lock_desktop
 else
-  is_passwd_set || askpwd
-  [ "$?" = "0" ] && lock_desktop || exit 1
+  if is_passwd_set || askpwd ; then
+    lock_desktop
+  else
+    exit 1
+  fi
 fi
 
 ## END OF FILE #################################################################