unsetenv

Remove environment variable

Since R2022b

Syntax

unsetenv(varname)

Description

unsetenv(varname) removes the operating system environment variable varname. If any elements in varname do not exist, then unsetenv has no effect.

Examples

Create and Test Environment Variable

Create environment variable myVar, and then check that it exists.

setenv("myVar","myValue");
isenv("myVar")

ans = logical
   1

Remove myVar, and then check that it no longer exists.

unsetenv("myVar");
isenv("myVar")

ans = logical
   0

Create and Test Multiple Environment Variables

Create multiple environment variables, and then check that they exist.

setenv(["Var1" "Var2" "Var3" "Var4"],["Val1" "Val2" "Val3" "Val4"]);
isenv(["Var1" "Var2"; "Var3" "Var4"])

ans = 2x2 logical array

   1   1
   1   1

Remove two of the environment variables using unsetenv, and then check that they no longer exist.

unsetenv(["Var1" "Var4"]);
isenv(["Var1" "Var2"; "Var3" "Var4"])

ans = 2x2 logical array

   0   1
   1   0

You can also remove environment variables using setenv with missing. Change the value of one environment variable and remove another.

setenv(["Var2" "Var3"],["ValB" missing]);
isenv(["Var1" "Var2"; "Var3" "Var4"])

ans = 2x2 logical array

   0   1
   0   0

Input Arguments

varname — Environment variable names

string scalar | character vector | string array | cell array of character vectors

Environment variable names, specified as a string scalar, character vector, string array, or cell array of character vectors.

Example: "PATH"

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• Code generation does not support the use of unsetenv inside parfor loops.

Version History

Introduced in R2022b

R2023a: Remove multiple environment variables

Remove multiple environment variables by using unsetenv with a string array or cell array of character vectors as input.