Big Sur - LaunchAgents - Load error 5: input/output error

Hello, Discovering my plist was not working since the Big Sur update, it seems the issue was my shell script was located in the ~/Documents/ folder, and seen as forbidden for security reasons. I moved my script in another folder (in ~/ ), unload and load again, and it worked.

Hello, the same happened to my system. I placed a small shell script in /usr/local/bin and it worked fine when I call it from the Terminal. After trying to load the launchctl command I got the "Load failed: 5: Input/output error" My plist file was very simple and plutil check was w/o any complains.

[mf@Server]:/Users/xyz/Library/LaunchAgents $ launchctl load local.demo.plist Load failed: 5: Input/output error Try running launchctl bootstrap as root for richer errors.




[mf@Server]:/Users/xyz/Library/LaunchAgents $ plutil local.demo.plist local.demo.plist: OK

After moving this script into /Users/xyz/ it worked fine.

Consider this small script:

% cat /usr/local/bin/greetings.sh 
#! /bin/sh

logger 'Hello Cruel World!'

It’s marked as executable:

% ls -l /usr/local/bin/greetings.sh 
-rwxr-xr-x  1 root  wheel  40  9 Jul 12:23 /usr/local/bin/greetings.sh

Now consider this launchd property list file:

% cat com.example.test665661.plist 
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.example.test665661</string>
    <key>ProgramArguments</key>
    <array>
        <string>/usr/local/bin/greetings.sh</string>
    </array>
</dict>
</plist>

You can load this as a job:

% launchctl load com.example.test665661.plist 

IMPORTANT Because I didn’t use sudo, this is loaded as a launchd agent in the current session.

And then start it:

% launchctl start com.example.test665661     

And in console you see this:

type: default
time: 12:32:02.647234+0100
process: logger
category: -
message: Hello Cruel World!

I ran this all on macOS 13.4.1 but it should work this way on any version of macOS that supports launchd (so 10.5 and later).

Oh, and to tidy up:

% launchctl unload com.example.test665661.plist
% rm com.example.test665661.plist 
% sudo rm /usr/local/bin/greetings.sh

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

For me, the plist having write access for everyone was the problem. I did chmod go-w on it and it worked.

Why is the launchd system so fragile and uncommunicative? It's like they don't want developers to use it. I've raised a bug with Apple.

https://feedbackassistant.apple.com/feedback/15371740

It's like they don't want developers to use it.

Actually, that’s kinda right. We always intended to create a proper API for managing launchd jobs it’s just that for… well… reasons… it took a long time coming. In the meantime, the only alternative was to mess around with launchd property lists and launchctl )-:

The good news is that there are much better options these days:

• Many of the things that you’d previously did with a launchd daemon are now done with a system extension, managed via the System Extensions framework.

• For other stuff, you have the SMAppService API.

In both cases the system is responsible for managing the launchd property list, which avoids many of the issues being discussed in this thread. If you can adopt these APIs, I recommend that you do so.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"