Category: <span>MAC</span>

Published 06/02/2025 by

How to Install watch on macOS Sequoia

The watch command is a useful utility in Unix-like systems that allows you to execute a command periodically and display its output. However, macOS does not come with watch pre-installed. If you’re running macOS Sequoia and want to use watch, follow the steps below to install it.

Recently i switch my mabook to a new MacBook Pro M2 and try to use the command to watch some openshift logs and i got the following result:

To install just use Homebrew. 

brew install watch

Using watch on macOS

Now that watch is installed, you can start using it. The basic syntax is:

watch -n <seconds> <command>

For example, to monitor the disk usage of your system every two seconds, you can run:

watch -n 2 df -h

Additional Options

  • -d: Highlights the differences between updates.
  • -t: Turns off the title/header display.
  • -b: Beeps if the command exits with a non-zero status.

Alternative: Using a while Loop

If you prefer not to install watch, you can achieve similar functionality using a while loop in the terminal:

while true; do <command>; sleep <seconds>; done

For example:

while true; do df -h; sleep 2; done

This method works in any macOS version without requiring additional installations.

Linux MAC

Published 05/03/2023 by

Error: podman-machine-default: VM already exists

This error appears today on my MAC using macOS 12.6 Monterey. I don’t know the cause and . It was woking last time i used podman on this MAC.

To solve the problem:

podman machine rm podman-machine-default

brew uninstall podman

brew install podman

podman machine init

Cloud MAC

podman

Published 05/06/2019 by

Converting M4V to MP4 and WEBM with FFmpeg

This month i am creating a Course about AI & IoT   (AI & IoT Fundamentals).

The course are about AI and IoT in general but i will use IBM Watson APIs, IBM Watson IoT and off course Node-Red and Raspberry Pi to make the excersices.

The course is 15 hours long (lots off video) plus the exercises.

Using the Keynote to generate de videos is fine but when i export the video the only option is M4V type.  To convert the videos i am usin FFmpeg.

1 – Install FFmpeg brew install ffmpeg

2 – Convert to mp4 using ffmpeg -i input.m4v out.mp4

3 – Convert to webm ffmpeg -i input.m4v output.webm

 

AI IoT MAC

Published 06/05/2018 by

Setup command line tools to work with IBM Cloudant

Command line tools are always welcome.  Today i need to setup my MAC to work with IBM Cloudant

Install curl on your MAC if you haven’t done it yet.

1 – You need to setup the Cloudant DB using your IBM Cloud account.

2 – Go to service credentials and get your username, password and hostname

Sample:
"username": "xxxx-xxx-xxx-bluemix",
"password": "12345678901234567890",
"host": "xxxx-xxx-xxx-bluemix.cloudant.com"

3 – Test the connection

curl –v –u xxxx-xxx-xxx-bluemix 'https://xxxx-xxx-xxx-bluemix.cloudant.com'

The command will prompt for the password: 12345678901234567890

You will see a lot off lines but pay attention on the line Authorization: Basic. This will be used to setup acurl (authorized curl) to avoid type the password every time you use curl.

* Using HTTP2, server supports multi-use
* Connection state changed (HTTP/2 confirmed)
* Copying HTTP/2 data in stream buffer to connection buffer after upgrade: len=0
* Server auth using Basic with user ‘xxxx-xxx-xxx-bluemix’
* Using Stream ID: 1 (easy handle 0x7fabd0805800)
> GET / HTTP/2
> Host: xxxx-xxx-xxx-bluemix.cloudant.com
> Authorization: Basic asddadasdDASDdaDadaDSERQERQRQERQEDSGSFDGSFDG==

4 – Edit the .bash_profile or .bashrc file in any text editor. For example, from the command line, issue the following command:
open –e .bash_profile

5 – Add the following line to the file, then save the file.
alias acurl="curl -s --proto '=https' -g -H 'Authorization: Basic asddadasdDASDdaDadaDSERQERQRQERQEDSGSFDGSFDG=='"

6 – On the terminal run : source .bash_profile

7 – Issue a command using the new alias. For example, issue a command to view your account information.
acurl -X GET 'https://xxxx-xxx-xxx-bluemix.cloudant.com'

TIP: The hostname is not friendly you can edit your hosts file and create an alias:

On MAC terminal type: sudo vi /etc/hosts

ping your hostname to get the ip address

add a line like this one bellow:

<ip address>  xxxx-xxx-xxx -bluemix.cloudant.com  keniodb.cloudant.com

Save the hosts file

test the connection

acurl -X GET 'https://keniodb.cloudant.com

 

Linux MAC

cloudant

Published 05/04/2018 by

Rename several files on MAC using command line

Today i need to rename lots of files from .txt to .json.   I type the following on the terminal window:

for f in *.txt; do
mv "$f" "$(basename "$f" .txt).json"
done

MAC

MAC