exist (MATLAB Function Reference)

Check if a variable or file exists

Syntax

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')

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

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.