-1

I have this simple bash script called get-volume.sh:

mutedStatus=`amixer -c 0 -D pulse get Master | tail -n 1 | grep -c '\[on\]'`

echo $mutedStatus

if "$mutedStatus" -eq 0; then
    echo 'x'
else
    echo `amixer get Master | awk -F'[]%[]' '/%/ {if ($7 == "off") { print "MM" } else { print $2 }}' | head -n 1`
fi

exit 0

It should

  1. populate the mutedStatus variable with 1 if unmuted and 0 if muted
  2. if muted, echo 'x', else echo the volume
  3. exit

But when I run the script with bash get-volume.sh I get this irritating message:

1
get-volume.sh: line 7: 1: command not found
100

why is it giving that error?

It seems to be trying to execute my variable, which is where 1: comes from, as when I mute my system the message changes to

get-volume.sh: line 7: 0: command not found
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6
  • 1
    I think it's just a simple syntax error. See acloudguru.com/blog/engineering/… Commented Dec 31, 2021 at 23:53
  • 1
    Looks like you figured it it out. BTW the command at line 3 is invoked immediately at line 3, not when the variable is referenced as you seemed to indicate. Commented Dec 31, 2021 at 23:56
  • 2
    -eq is not a shell operator; it's an argument to be interpreted by the test command. You are literally trying to run a command named 1 with arguments -eq and 0. Commented Dec 31, 2021 at 23:57
  • The condition in a shell if statement is a command, not an expression. The condition is true if the command succeeds, false if it fails. [ is a special (often built-in) command that evaluates an expression. Commented Dec 31, 2021 at 23:59
  • BTW #!.bin/bash should be: #!/bin/bash Commented Dec 31, 2021 at 23:59

1 Answer 1

Reset to default
0

Solution is to write the if statement like this

...
if [ "$mutedStatus" -eq 0 ] ; then
...

Notice the space after [ and before ] - without this the command fails with

get-volume.sh: line 7: [1: command not found

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1 Comment

Other ways of writing the if statement include if test "$mutedStatus" -eq 0, if [[ "$mutedStatus" -eq 0 ]], if (( mutedStatus == 0 )) , and if let "mutedStatus == 0" and many more. However for portability, one such use the Posixly correct war, i.e. if [ "$mutedStatus" -eq 0 ]

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