MATLAB Functions

Check if a variable or file exists

a = exist('item')
ident = exist('item',kind)

Description

a = exist('item')

returns the status of the variable or file item:


`0`	If `item` does not exist.
`1`	If the variable `item` exists in the workspace.
`2`	If `item` is an M-file or a file of unknown type.
`3`	If `item` is a MEX-file.
`4`	If `item` is a MDL-file.
`5`	If `item` is a built-in MATLAB function.
`6`	If `item` is a P-file.
`7`	If `item` is a directory.

exist('item') or exist('item.ext')returns 2 if item is on the MATLAB search path but the filename extension (ext) is not m, p, or mex. item may be a MATLABPATH relative partial pathname.

ident = exist('item','kind') returns logical true (1) if an item of the specified kind is found, and returns 0 otherwise. kind may be:


`'var'`	Checks only for variables.
`'builtin'`	Checks only for built-in functions.
`'file'`	Checks only for files.
`'dir'`	Checks only for directories.

Examples

exist can check whether a MATLAB function is built-in or a file:

ident = exist('plot')
ident =
      5

plot is a built-in function.