cd — Change or query the current working folder in MATLAB and RunMat.

cd displays the current working folder or switches to a different folder. Relative path resolution and session behavior follow MATLAB semantics for script and interactive workflows.

Syntax

folder = cd()
folder = cd(folder)

Inputs

Returns

Errors

How cd works

• cd with no input returns the absolute path of the current folder as a character row vector (1×N).
• cd(newFolder) changes the working folder and returns the previous folder, enabling the classic MATLAB pattern old = cd(new); ...; cd(old);.
• Accepts character vectors and string scalars. String arrays must contain exactly one element. Other types raise cd: folder name must be a character vector or string scalar.
• Supports relative paths (for example cd('..')), absolute paths, and the shell-style ~ expansion to jump to the user home folder.
• MATLAB command form is supported for path-like folder arguments, including cd .., cd ./data, and cd ~/project.
• Emits descriptive errors when the folder does not exist or cannot be accessed.
• Does not modify GPU residency; path values always live on the host.

Does RunMat run cd on the GPU?

cd performs host-side path manipulation and process-level directory changes. When callers supply the folder argument from GPU memory, RunMat gathers the value before resolving the new path. Providers are not expected to implement hooks for this builtin, and no GPU kernels run as part of cd.

GPU memory and residency

cd operates entirely on the CPU, so there is no performance benefit to moving folder arguments onto the GPU. If a path value is already wrapped in gpuArray, RunMat transparently gathers it before resolving the change directory request. Scripts can keep using plain character vectors or string scalars without worrying about residency.

Examples

Display The Current Working Folder In RunMat

current = cd

Expected output:

% current is the absolute path to the folder where RunMat is executing

Change Directory To A Project Subfolder

projectRoot = pwd;
mkdir("data/logs");
old = cd("data/logs");
% ... work inside the logs folder ...
cd(old)

Expected output:

% old contains the previous folder so you can restore it later, and the final cd(old)
% call brings you back to projectRoot

Navigate Up One Level From The Current Folder

old = cd("..")

Expected output:

% RunMat moves to the parent folder and old captures the prior location

Navigate With MATLAB Command Syntax

projectRoot = pwd;
mkdir("scratch");
cd scratch
cd ..
backAtRoot = strcmp(pwd, projectRoot)

Expected output:

backAtRoot =
  logical
   1

Switch To Your Home Folder With cd ~

old = cd("~")

Expected output:

% Changes to the user home directory; old stores the previous folder

Capture The Previous Folder And Restore Later

old = cd("results");
% ... run code that writes outputs into results ...
cd(old)

Expected output:

% The working folder is restored to its original location at the end

Handle Missing Folders With A try/catch Block

try
    cd("missing-folder");
catch err
    disp(err.message);
end

Expected output:

% Displays a descriptive error such as:
% "cd: unable to change directory to 'missing-folder' (No such file or directory)"

Using cd with coding agents

Open a RunMat example with live inputs, then ask the agent to explain how cd changes the result.

FAQ

Related Io functions

Open-source implementation

Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how cd is executed, line by line, in Rust.

• View the source for cd in Rust on GitHub
• Learn how the RunMat runtime works
• Found a bug? Open an issue with a minimal reproduction.

About RunMat

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