Campus Livre
isenv
Tests whether an environment variable is defined.
Category: Environment and Settings > System Commands
Syntax
tf = isenv(name)Returns true when the variable name exists in the process environment.
Description
isenv gives a direct yes or no, without reading the value. Variables created with setenv count; variables removed with unsetenv do not.
Input arguments
name- Variable name, as a character vector or string scalar.
Output arguments
tf- Logical scalar.
Example
Defined or not
disp(isenv('MY_FLAG'))
setenv('MY_FLAG', '1');
disp(isenv('MY_FLAG'))
unsetenv('MY_FLAG');
disp(isenv('MY_FLAG'))Output
0
1
0