Multiples fixes:

* [volume: Use '/usr/bin/env bash' as shebang](https://github.com/vivien/i3blocks-contrib/commit/cd182fd4f2e6d7e100e2aaae06c67d9905e46457#diff-210ab9e731c9c36c2c38db15c28a8d1c)

On some systems (e.g. NixOS, openBSD) Bash isn't located or symlinked at
`/bin/bash`. This change ensures that the correct path is used across
different operating systems.

* [volume: add LABEL support](https://github.com/vivien/i3blocks-contrib/commit/be3f4ae715f7a76cc54653543775a1aea6c65fff#diff-210ab9e731c9c36c2c38db15c28a8d1c)

* [volume: use injected properties](https://github.com/vivien/i3blocks-contrib/commit/50b2b6ee539cc636a303a00450909733d13dca14#diff-210ab9e731c9c36c2c38db15c28a8d1c)

See #132

* [volume: pulse-detection: explicitly try the "pulse" device](https://github.com/vivien/i3blocks-contrib/commit/777a056cce442dd4611cad9ff82ed3c21fa73ffd#diff-210ab9e731c9c36c2c38db15c28a8d1c)

Because it's available on some systems (for which pulse is the right
option), but not the default, so `amixer info` will not give the right
result. When this command succeeds, there is no more need to check the
output.

Additionally removed a wrong test bracket (not neccessary and not
working for all bash versions).

* [volume: don't check for pulse via lsmod but command](https://github.com/vivien/i3blocks-contrib/commit/67dba4fca91b6dcdc3deb00c74ed4cab1da22598#diff-210ab9e731c9c36c2c38db15c28a8d1c)

- check if command `pulseaudio` exists
- check if pulse is running
- in the case that pulse is detected, still check if the mixer name
  "pulse" exists

- instruction for manual setting in README

Fixes vivien/i3blocks#236
Fixes vivien/i3blocks#201
Fixes: vivien/i3blocks#281

* [volume: allow device names to include numbers](https://github.com/vivien/i3blocks-contrib/commit/1b3efc6e44ca2a01da2fb23ac60dbfc49bdec33c#diff-210ab9e731c9c36c2c38db15c28a8d1c):

Fixes: vivien/i3blocks#281

3 files changed, 32 insertions, 17 deletions

diff --git a/config b/config
index 4ae6379..60803fc 100644
--- a/config
+++ b/config
@@ -225,9 +225,10 @@ exec --no-startup-id conky
 # exec --no-startup-id aarchup
 
 # Pulse Audio controls
-bindsym XF86AudioRaiseVolume exec --no-startup-id amixer -q -D pulse sset Master 5%+; exec pkill -SIGRTMIN+10 i3blocks #increase sound volume
-bindsym XF86AudioLowerVolume exec --no-startup-id amixer -q -D pulse sset Master 5%-; exec pkill -SIGRTMIN+10 i3blocks #decrease sound volume
-bindsym XF86AudioMute exec --no-startup-id amixer -q -D pulse sset Master toggle; exec pkill -SIGRTMIN+10 i3blocks # mute sound
+exec --no-startup-id pulseaudio --start
+bindsym XF86AudioRaiseVolume exec --no-startup-id amixer -q -D pulse sset Master 5%+ && pkill -SIGRTMIN+10 i3blocks #increase sound volume
+bindsym XF86AudioLowerVolume exec --no-startup-id amixer -q -D pulse sset Master 5%- && pkill -SIGRTMIN+10 i3blocks #decrease sound volume
+bindsym XF86AudioMute exec --no-startup-id amixer -q -D pulse sset Master toggle && pkill -SIGRTMIN+10 i3blocks # mute sound
 
 # Enable devices USB
 # bindsym $mod+m exec --no-startup-id "udisksctl mount -b /dev/sdb1"
diff --git a/i3blocks.conf b/i3blocks.conf
index bcbe309..d5a4d0e 100644
--- a/i3blocks.conf
+++ b/i3blocks.conf
@@ -47,11 +47,12 @@ signal=10
 [volume]
 #label=VOL
 label=♪
-instance=Master
-# instance=PCM
 # interval=once
 interval=5
 signal=10
+#STEP=5%
+#MIXER=[determined automatically]
+#SCONTROL=[determined automatically]
 
 # Memory usage
 #
diff --git a/scripts/i3blocks/volume b/scripts/i3blocks/volume
index a55db88..3b2a7f4 100755
--- a/scripts/i3blocks/volume
+++ b/scripts/i3blocks/volume
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright (C) 2014 Julien Bonjean <julien@bonjean.info>
 # Copyright (C) 2014 Alexander Keller <github@nycroth.com>
 
@@ -18,26 +18,37 @@
 #------------------------------------------------------------------------
 
 # The second parameter overrides the mixer selection
-# For PulseAudio users, use "pulse"
+# For PulseAudio users, eventually use "pulse"
 # For Jack/Jack2 users, use "jackplug"
 # For ALSA users, you may use "default" for your primary card
 # or you may use hw:# where # is the number of the card desired
-MIXER="default"
-[ -n "$(lsmod | grep pulse)" ] && MIXER="pulse"
-[ -n "$(lsmod | grep jack)" ] && MIXER="jackplug"
-MIXER="${2:-$MIXER}"
+if [[ -z "$MIXER" ]] ; then
+    MIXER="default"
+    if command -v pulseaudio >/dev/null 2>&1 && pulseaudio --check ; then
+        # pulseaudio is running, but not all installations use "pulse"
+        if amixer -D pulse info >/dev/null 2>&1 ; then
+            MIXER="pulse"
+        fi
+    fi
+    [ -n "$(lsmod | grep jack)" ] && MIXER="jackplug"
+    MIXER="${2:-$MIXER}"
+fi
 
 # The instance option sets the control to report and configure
 # This defaults to the first control of your selected mixer
 # For a list of the available, use `amixer -D $Your_Mixer scontrols`
-SCONTROL="${BLOCK_INSTANCE:-$(amixer -D $MIXER scontrols |
-                  sed -n "s/Simple mixer control '\([A-Za-z ]*\)',0/\1/p" |
-                  head -n1
-                )}"
+if [[ -z "$SCONTROL" ]] ; then
+    SCONTROL="${BLOCK_INSTANCE:-$(amixer -D $MIXER scontrols |
+                      sed -n "s/Simple mixer control '\([^']*\)',0/\1/p" |
+                      head -n1
+                    )}"
+fi
 
 # The first parameter sets the step to change the volume by (and units to display)
 # This may be in in % or dB (eg. 5% or 3dB)
-STEP="${1:-5%}"
+if [[ -z "$STEP" ]] ; then
+    STEP="${1:-5%}"
+fi
 
 #------------------------------------------------------------------------
 
@@ -51,12 +62,14 @@ volume() {
 }
 
 format() {
+
   perl_filter='if (/.*\[(\d+%)\] (\[(-?\d+.\d+dB)\] )?\[(on|off)\]/)'
   perl_filter+='{CORE::say $4 eq "off" ? "MUTE" : "'
   # If dB was selected, print that instead
   perl_filter+=$([[ $STEP = *dB ]] && echo '$3' || echo '$1')
   perl_filter+='"; exit}'
-  perl -ne "$perl_filter"
+  output=$(perl -ne "$perl_filter")
+  echo "$LABEL$output"
 }
 
 #------------------------------------------------------------------------