You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: spm_check_version.m
    path of file: ./repos/spm
    
    the code of the file until where you have to start completion: function varargout = spm_check_version(tbx,chk)
% Check a version number against a Toolbox version
%
% FORMAT tbx = spm_check_version
% tbx    - toolbox name {'matlab','octave',...}
%
% FORMAT v = spm_check_version(tbx)
% tbx    - toolbox name {'matlab','octave','spm','signal',...}
%
% v      - version number {string}
%
% FORMAT status = spm_check_version(tbx,chk)
% tbx    - toolbox name {'matlab','octave','signal',...}
% chk    - version number to be checked {string}
%
% status - outcome of the comparison:
%          -1: Toolbox version is earlier than the user supplied version
%           0: Toolbox and user versions are the same
%           1: Toolbox version is later than the user supplied version
%              Think of it this way, the sign of status is determined by
%              MATLAB_TOOLBOX_VERSION - USER_VERSION (i.e., THE VERSION YOU
%              INPUT).
%__________________________________________________________________________
%
% This function checks if a user supplied version number is less than,
% equal to or greater than the version number of specified toolbox. If no
% toolbox is specified the function checks the version of MATLAB. User
% defined toolboxes can be checked but the Contents.m file must conform
% to the specification defined in ver.m
%
% This function assumes that the version number is really a text string
% with fields major.minor.revision.build. Other formats are not supported.
% Checking is done to the level specified by the input version. Thus an
% input of '7' will be rated as the same version as 7.1, but 7.0 would be
% rated as earlier than 7.1.
%__________________________________________________________________________
%
% EXAMPLES:
%
% If the MATLAB version is 7.1.0.83, and the user supplied version is '7':
% status = spm_check_version('matlab','7');
% returns status == 0   : major revision numbers are the same.
%
% If the MATLAB version is 7.1.0.0, and the user supplied version is '7.1':
% status = spm_check_version('matlab','7');
% returns status == 0   : major and minor revision numbers are the same.
%
% If the MATLAB version is 7.1.0.83, and the user supplied version is '7.2':
% status = spm_check_version('matlab','7.2');
% returns status == -1   : major + minor revision is earlier for MATLAB.
%
% If the MATLAB version is 6.5.1, and the user supplied version is '6.5.0'.
% status = spm_check_version('matlab','6.5.0');
% returns status == 1     : major + minor + release revision is later
%                           for MATLAB
% The statement ( spm_check_version('matlab','6.5.0') > 0 ) is true for
% all MATLAB Toolbox versions after 6.5.0.
%__________________________________________________________________________
%
% See also VERSION, VER, VERLESSTHAN, ISMATLABRELEASEOLDERTHAN
%__________________________________________________________________________

% Darren Gitelman
% Copyright (C) 2006-2022 Wellcome Centre for Human Neuroimaging


%-Detect software used

    
function varargout = spm_check_version(tbx,chk)
% Check a version number against a Toolbox version
%
% FORMAT tbx = spm_check_version
% tbx    - toolbox name {'matlab','octave',...}
%
% FORMAT v = spm_check_version(tbx)
% tbx    - toolbox name {'matlab','octave','spm','signal',...}
%
% v      - version number {string}
%
% FORMAT status = spm_check_version(tbx,chk)
% tbx    - toolbox name {'matlab','octave','signal',...}
% chk    - version number to be checked {string}
%
% status - outcome of the comparison:
%          -1: Toolbox version is earlier than the user supplied version
%           0: Toolbox and user versions are the same
%           1: Toolbox version is later than the user supplied version
%              Think of it this way, the sign of status is determined by
%              MATLAB_TOOLBOX_VERSION - USER_VERSION (i.e., THE VERSION YOU
%              INPUT).
%__________________________________________________________________________
%
% This function checks if a user supplied version number is less than,
% equal to or greater than the version number of specified toolbox. If no
% toolbox is specified the function checks the version of MATLAB. User
% defined toolboxes can be checked but the Contents.m file must conform
% to the specification defined in ver.m
%
% This function assumes that the version number is really a text string
% with fields major.minor.revision.build. Other formats are not supported.
% Checking is done to the level specified by the input version. Thus an
% input of '7' will be rated as the same version as 7.1, but 7.0 would be
% rated as earlier than 7.1.
%__________________________________________________________________________
%
% EXAMPLES:
%
% If the MATLAB version is 7.1.0.83, and the user supplied version is '7':
% status = spm_check_version('matlab','7');
% returns status == 0   : major revision numbers are the same.
%
% If the MATLAB version is 7.1.0.0, and the user supplied version is '7.1':
% status = spm_check_version('matlab','7');
% returns status == 0   : major and minor revision numbers are the same.
%
% If the MATLAB version is 7.1.0.83, and the user supplied version is '7.2':
% status = spm_check_version('matlab','7.2');
% returns status == -1   : major + minor revision is earlier for MATLAB.
%
% If the MATLAB version is 6.5.1, and the user supplied version is '6.5.0'.
% status = spm_check_version('matlab','6.5.0');
% returns status == 1     : major + minor + release revision is later
%                           for MATLAB
% The statement ( spm_check_version('matlab','6.5.0') > 0 ) is true for
% all MATLAB Toolbox versions after 6.5.0.
%__________________________________________________________________________
%
% See also VERSION, VER, VERLESSTHAN, ISMATLABRELEASEOLDERTHAN
%__________________________________________________________________________

% Darren Gitelman
% Copyright (C) 2006-2022 Wellcome Centre for Human Neuroimaging


%-Detect software used
%==========================================================================
if ~nargin || isempty(tbx)
    if exist('OCTAVE_VERSION','builtin')
        tbx = 'octave';
    else
        tbx = 'matlab';
    end