From e17c3d7ce93c20feeec71576e3bfe63e2d83edff Mon Sep 17 00:00:00 2001
From: "stefano.salvi" <stefano.salvi@noreply.localhost>
Date: Thu, 6 Nov 2025 15:30:59 +0000
Subject: [PATCH] three-screens

Soluzione per tre schermi, come descritta nelle slide
---
 three-screens | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)
 create mode 100644 three-screens

diff --git a/three-screens b/three-screens
new file mode 100644
index 0000000..29a8e6b
--- /dev/null
+++ b/three-screens
@@ -0,0 +1,101 @@
+#!/bin/bash
+function setClone  {
+        PRIMARY=$1
+        SECONDARY=$2
+        while read -r l
+        do
+                if echo $l | grep -Eq "^[a-zA-Z]"
+                then
+                        DEV=`echo $l | sed -e "s/ .*$//"`
+                        MODELIST=`echo ${DEV} | sed -e "s/-/_/g"`_MODES
+                        typeset -n CML=$MODELIST
+                elif echo $l | grep -q "^[0-9]"
+                then
+                        MODE=`echo $l | sed -e "s/ .*$//"`
+                        CML="${!MODELIST} $MODE"
+                fi
+        done
+        PRIMARY_LIST=`echo ${PRIMARY} | sed -e "s/-/_/g"`_MODES
+        SECONDARY_LIST=`echo ${SECONDARY} | sed -e "s/-/_/g"`_MODES
+        typeset -n PRIMARY_MODES=$PRIMARY_LIST
+        typeset -n SECONDARY_MODES=$SECONDARY_LIST
+        MODE=""
+        for pm in $PRIMARY_MODES
+        do
+                for sm in $SECONDARY_MODES
+                do
+                        if [ $pm = $sm -a -z $MODE ]
+                        then
+                                MODE=$pm
+                        fi
+                done
+        done
+        if [ -z "$MODE" ]
+        then
+                echo Nessun modo comune ERRORE!
+                exit 2
+        else
+                echo $MODE
+
+                xrandr --output $PRIMARY --mode $MODE
+                xrandr --output $SECONDARY --mode $MODE
+                xrandr --output $SECONDARY --same-as $PRIMARY
+        fi
+}
+
+POSITION='right-of'
+if [ -n "$1" ]
+then
+        if [ $1 = '-l' ]
+        then
+                POSITION='left-of'
+        elif [ $1 = '-r' ]
+        then
+                POSITION='right-of'
+        elif [ $1 = '-u' ]
+        then
+                POSITION='above'
+        else
+                echo "-l Display piccolo a sinisitra"
+                echo "-r Display piccolo a destra"
+                echo "-l Display piccolo sopra"
+                exit 1
+        fi
+fi
+
+
+PRIMARY=`xrandr | grep " connected" | grep primary | sed -e "s/ .*$//"`
+# https://stackoverflow.com/questions/613572/capturing-multiple-line-output-into-a-bash-variable
+declare R=($(xrandr | grep " connected" | grep -v primary | sed -e "s/[^ ]* c[^ ]* \([0-9]*\).*$/\1/"))
+
+if expr ${R[0]} \< ${R[1]}
+then
+  SRES=${R[0]}
+else
+  SRES=${R[1]}
+fi
+
+echo risoluzion schermo piccolo $SRES
+
+SECONDARY=`xrandr | grep " connected" | grep -v primary | grep -v ${SRES}x | sed -e "s/ .*$//"`
+TERTIARY=`xrandr | grep " connected" | grep -v primary | grep ${SRES}x | sed -e "s/ .*$//"`
+if [ -z $SECONDARY ]
+then
+        SECONDARY=`xrandr | grep " connected" | grep -v primary | grep ${SRES}x | grep -v $TERTIARY | sed -e "s/ .*$//"`
+fi
+
+# SECONDARY=DP-1
+# TERTIARY=DP-2
+
+echo Primary $PRIMARY
+echo Secondary $SECONDARY
+echo Tertiary $TERTIARY
+
+xrandr | setClone $PRIMARY $SECONDARY
+xrandr --output $TERTIARY --$POSITION $PRIMARY
+
+
+# echo "xrandr | setClone $PRIMARY $SECONDARY same-as"
+# xrandr | setClone $SECONDARY $TERTIARY same-as
+# echo "xrandr --output $TERTIARY --$POSITION $PRIMARY"
+# xrandr --output $SECONDARY --$POSITION $PRIMARY