bash script for switch stealth mode on macos-CodePudding

To solve a specific problem i'm trying to make a switch for stealth mode on macos using bash

Here is part of the code:

STEALTH_STATUS=$(/usr/libexec/ApplicationFirewall/socketfilterfw --getstealthmode)
if [ "$STEALTH_STATUS" = "Stealth mode enabled" ]; then
    /usr/libexec/ApplicationFirewall/socketfilterfw --setstealthmode off
else
    /usr/libexec/ApplicationFirewall/socketfilterfw --setstealthmode on
fi

Everything seems to look ok (right?), but it doesn't work. For debug, I changed the reaction to the condition to True and False:

STEALTH_STATUS=$(/usr/libexec/ApplicationFirewall/socketfilterfw --getstealthmode)
if [ "$STEALTH_STATUS" = "Stealth mode enabled" ]; then
    echo "True"
else
    echo "False"
fi

(if we use a $STEALTH_STATUS without ", we get an error line 2: [: too many arguments)

And when executing this code, it always get False, which makes it clear that the result of executing the function to set $STEALTH_STATUS is not equal to "Stealth mode enabled"

But if we run the command in the shell, we can make sure that the mode is enable now

$ /usr/libexec/ApplicationFirewall/socketfilterfw --getstealthmode
> Stealth mode enabled

Just another one check to make a sure

STEALTH_STATUS=$(/usr/libexec/ApplicationFirewall/socketfilterfw --getstealthmode)
STRING="Stealth mode enabled"

echo $STEALTH_STATUS
echo $STRING

if [ "$STEALTH_STATUS" = "$STRING" ]; then
    echo "True"
else
    echo "False"
fi

And we got...

> Stealth mode enabled
> Stealth mode enabled
> False

Can someone explain where I went wrong?

CodePudding user response：

The response from STEALTH_STATUS=$(/usr/libexec/ApplicationFirewall/socketfilterfw --getstealthmode) contains a trailing whitespace, so your if check is failing. You can see it by checking the length of the strings. One mechanism for trimming the whitespace is to pipe to xargs.

Here is a modified version of your script:

#!/bin/bash

current_status="$(/usr/libexec/ApplicationFirewall/socketfilterfw --getstealthmode | xargs)"
enabled="Stealth mode enabled"

echo "${current_status} length: ${#current_status}"
echo "${enabled} length: ${#enabled}"

if [ "$current_status" = "$enabled" ]; then
    echo "True"
else
    echo "False"
fi

Output:

$ ./script 
Stealth mode enabled length: 20
Stealth mode enabled length: 20
True

Output without the pipe to xargs:

$ ./script 
Stealth mode enabled  length: 21
Stealth mode enabled length: 20
False

(Note, you may also want to avoid using all-caps for your variable names per bash scripting best practices)