Solved: if directory exist

As a MATLAB developer, one of the first steps in managing files and directories is to check whether a directory exists. MATLAB provides a simple embedding function that can verify the existence. The function to use is ‘exist’ which returns a boolean value indicating whether the specified file or variable exists. Don’t forget to add here to separate the introduction from the rest of the text.

Checking if a Directory Exists in MATLAB

The base MATLAB function ‘exist(filename, ‘dir’) is commonly used to check whether a file or directory exists. When applied, it outputs a logical value of either 1 or 0. The number 1 is returned indicating that the directory exists, or 0 if the path does not correspond to an existing directory or if the directory is a masked MATLAB function.

To check if a directory exists, simply use the following code:

function dir_exists = directoryExists(directory)
    dir_exists = exist(directory, 'dir') == 7;

Step-by-step Explanation

The code starts with a function definition ‘directoryExists’, takes an input parameter ‘directory’- the name of the directory you intend to check. In the function body, ‘exist’ function is used to check if the directory exists.

  • exist(directory, ‘dir’): This MATLAB function checks if the path in the ‘directory’ variable exists and is a directory.
  • == 7: By using double equals ==, we indicate we want to compare the output of the preceding ‘exist’ function with the number 7. A return value of 7 from ‘exist’ function denotes that the name exists and is a directory.
  • dir_exists: This boolean value would be 1 (true) if the directory exists and 0 (false) otherwise. This value can later be used in logic operations.

Points to Consider

When using the ‘exist’ function, do note that MATLAB search for directories (and also files and variables) in its path. If you’re searching for a directory that should be on the MATLAB path but not found, it may be that the directory was added after MATLAB was started.

Another point to consider is that you must provide the exact pathname or filename — MATLAB does not support wildcard characters like ‘*’ and ‘?’ in the ‘exist’ function.

Other Related Functions and Libraries

There are various other functions related to file and path handling in MATLAB, such as ‘isfolder’, ‘isfile’, ‘mkdir’ (for creating a new directory), or ‘rmdir’ (for removing a directory). These might come in handy when dealing with files and directories. Note that some of these functions are only available in recent MATLAB versions, so always verify in documentation if a function is available in your MATLAB version.

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