TOPIC: GNU CORE UTILITIES
Grouping directories first in output from ls commands executed in terminal sessions on macOS and Linux
12th February 2026
This enquiry began with my seeing directories and files being sorted by alphabetical order without regard for type in macOS Finder. In Windows and Linux file managers, I am accustomed to directories and files being listed in distinct blocks, albeit within the same listings, with the former preceding the latter. What I had missed was that the ls command and its aliases did what I was seeing in macOS Finder, which perhaps is why the operating system and its default apps work like that.
Over to Linux
On the zsh implementation that macOS uses, there is no way to order the output so that directories are listed before files. However, the situation is different on Linux because of the use of GNU tooling. Here, the --group-directories-first switch is available, and I have started to use this on my own Linux systems, web servers as well as workstations. This can be set up in .bashrc or .bash_aliases like the following:
alias ls='ls --color=auto --group-directories-first'
alias ll='ls -lh --color=auto --group-directories-first'
Above, the --color=auto switch adds colour to the output too. Issuing the following command makes the updates available in a terminal session (~ is the shorthand for the home directory below):
source ~/.bashrc
Back to macOS
While that works well on Linux, additional tweaks are needed to implement the same on macOS. Firstly, you have to install Homebrew using this command (you may be asked for your system password to let the process proceed):
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
To make it work, this should be added to the .zshrc file in your home folder:
export PATH="/opt/homebrew/opt/coreutils/libexec/gnubin:$PATH"
Then, you need to install coreutils for GNU commands like gls (a different name is used to distinguish it from what comes with macOS) and adding dircolors gives you coloured text output as well:
brew install coreutils
brew install dircolors
Once those were in place, I found that adding these lines to the .zshrc file was all that was needed (note those extra g's):
alias ls='gls --color=auto --group-directories-first'
alias ll='gls -lh --color=auto --group-directories-first'
If your experience differs, they may need to be preceded with this line in the same configuration file:
eval "$(dircolors -b)"
The final additions then look like this:
export PATH="/opt/homebrew/opt/coreutils/libexec/gnubin:$PATH"
eval "$(dircolors -b)"
alias ls='gls --color=auto --group-directories-first'
alias ll='gls -lh --color=auto --group-directories-first'
Following those, issuing this command will make the settings available in your terminal session:
source ~/.zshrc
Closing Remarks
In summary, you have learned how to list directories before files, and not intermingled as is the default situation. For me, this discovery was educational and adds some extra user-friendliness that was not there before the tweaks. While we may be considering two operating systems and two different shells (bash and zsh), there is enough crossover to make terminal directory and file listing operations function consistently regardless of where you are working.
Something to try when you get a message like this caused by a filename with a leading hyphen: "mv: illegal option -- u"
3rd December 2024
Recently, I downloaded some WEBP files from Ideogram and attempted to move them to another folder. That is when I got the message that you see in the title of this entry. Because I had not looked at the filenames, I baffled when I got this from a simple command that I had been using with some success until then. Because I was using an iMac, I tried the suggestion of installing coreutils to get GNU mv and cp to see if that would help:
brew install coreutils
The above command gave me gmv and gcp for the GNU versions of mv and cp that comes with macOS. Trying gmv only got me the following message:
gmv: cannot combine --backup with --exchange, -n, or --update=none-fail
The ls command could list all files, but not the WEBP ones. Thus, I executed the following to show what I wanted:
ls | grep -i webp
That got around the problem by doing a subset of the directory listing. It was then that I spotted the leading hyphen. To avoid the problem tripping me up again, I renamed the offending file using this command:
mv -- -iunS9U4RFevWpaju6ArIQ.webp iunS9U4RFevWpaju6ArIQ.webp
Here, the -- switch tells the mv command not to look for any more options and only to expect filenames. When I tried enclosing the filename in quotes, I still got problems, even that might have because I was using double quotes instead of single quotes. Another option is to escape the leading hyphen like this:
mv ./-iunS9U4RFevWpaju6ArIQ.webp iunS9U4RFevWpaju6ArIQ.webp
Once the offending file was renamed, I could move the files to their final location. That could have used the -- option too, saving me an extra command, only for my wanting this not to trip me up again. Naturally, working in Finder might have avoided all this as much as not having a file with a leading hyphen in its name, but there would have been nothing to learn then.