echo on

fh_isstr = @isstr

fh_isstr =

  <a href="matlab:helpPopup function_handle" style="font-weight:bold">function_handle</a> with value:

    @isstr


functions (fh_isstr)

ans = 

  <a href="matlab:helpPopup struct" style="font-weight:bold">struct</a> with fields:

    function: 'isstr'
        type: 'simple'
        file: 'MATLAB built-in function'

which ('isstr')
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\strfun\isstr)
isstr (pi)

ans =

  <a href="matlab:helpPopup logical" style="font-weight:bold">logical</a>

   0

fh_isstr (pi)

ans =

  <a href="matlab:helpPopup logical" style="font-weight:bold">logical</a>

   0


cd subdir
[Warning: Function isstr has the same name as a MATLAB builtin. We suggest you rename the function to avoid a potential name conflict.] 
[> In <a href="matlab:matlab.internal.language.introspective.errorDocCallback('tstscript_isstr', 'D:\SVN\Octave\builtin-fh-tst\tstscript_isstr.m', 11)" style="font-weight:bold">tstscript_isstr</a> (<a href="matlab: opentoline('D:\SVN\Octave\builtin-fh-tst\tstscript_isstr.m',11,0)">line 11</a>)] 
[Warning: Function sin has the same name as a MATLAB builtin. We suggest you rename the function to avoid a potential name conflict.] 
[> In <a href="matlab:matlab.internal.language.introspective.errorDocCallback('tstscript_isstr', 'D:\SVN\Octave\builtin-fh-tst\tstscript_isstr.m', 11)" style="font-weight:bold">tstscript_isstr</a> (<a href="matlab: opentoline('D:\SVN\Octave\builtin-fh-tst\tstscript_isstr.m',11,0)">line 11</a>)] 

functions (fh_isstr)

ans = 

  <a href="matlab:helpPopup struct" style="font-weight:bold">struct</a> with fields:

    function: 'isstr'
        type: 'simple'
        file: 'MATLAB built-in function'

which ('isstr')
D:\SVN\Octave\builtin-fh-tst\subdir\isstr.m
isstr (pi)
not the builtin sin function!
fh_isstr (pi)

ans =

  <a href="matlab:helpPopup logical" style="font-weight:bold">logical</a>

   0


diary off