Linux retrieve monitor names

Question

Situation: I'm using multiple monitors and I want to get their names in bash. Currently I'm using Ubuntu 10.04.

I know about xrandr. From it I can get only statistics data. What I want is to read all monitor names in an array to work with them.

Is there a clear way to do that without cutting names from some kind of string? A clear way would be reading them from file. A not clear way would be to pipe xrandr output to some sort a function to cut names out from it.

Answer 1

Inspired by Beni's answer, this will read the EDID data using xrandr and extract the monitors names according to the EDID specification, with no need of any external tools like parse-edid:

#!/bin/bash
while read -r output hex conn; do
    [[ -z "$conn" ]] && conn=${output%%-*}
    echo "# $output $conn   $(xxd -r -p <<< "$hex")"
done < <(xrandr --prop | awk '
    !/^[ \t]/ {
        if (output && hex) print output, hex, conn
        output=$1
        hex=""
    }
    /ConnectorType:/ {conn=$2}
    /[:.]/ && h {
        sub(/.*000000fc00/, "", hex)
        hex = substr(hex, 0, 26) "0a"
        sub(/0a.*/, "", hex)
        h=0
    }
    h {sub(/[ \t]+/, ""); hex = hex $0}
    /EDID.*:/ {h=1}
    END {if (output && hex) print output, hex, conn}
    ' | sort
)

Uses awk to precisely extract the monitor name only, and no extra garbage from the EDID, hence "magic numbers" like 000000fc00, 26 and 0a. Finally uses xxd to convert from hex to ASCII, printing one monitor name per line.

Based on this solution I made a handy script to switch monitors, which can also be used to simply list monitor info:

$ monitor-switch --list
Connected monitors:
# DFP5  HDMI    HT-R391
# DFP7  DVI-I   DELL U2412M

$ monitor-switch --list
Connected monitors:
# DisplayPort-1 DisplayPort DELL U2412M
# DisplayPort-3 DisplayPort DELL U2415
# HDMI-A-2      HDMI        LG TV