Command Line Options

Next: Startup Files, Up: Invoking Octave from the Command Line

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2.1.1 Command Line Options

Here is a complete list of all the command line options that Octave accepts.

--debug

-d

Enter parser debugging mode. Using this option will cause Octave's parser to print a lot of information about the commands it reads, and is probably only useful if you are actually trying to debug the parser.

--echo-commands

-x

Echo commands as they are executed.

--eval code

Evaluate code and exit when done unless --persist is also specified.

--exec-path path

Specify the path to search for programs to run. The value of path specified on the command line will override any value of OCTAVE_EXEC_PATH found in the environment, but not any commands in the system or user startup files that set the built-in variable EXEC_PATH.

--help

-h

-?

Print short help message and exit.

--image-path path

Specify the path to search for images. The value of path specified on the command line will set the value of IMAGE_PATH found in the environment.

--info-file filename

Specify the name of the info file to use. The value of filename specified on the command line will override any value of OCTAVE_INFO_FILE found in the environment, but not any commands in the system or user startup files that use the info_file function.

--info-program program

Specify the name of the info program to use. The value of program specified on the command line will override any value of OCTAVE_INFO_PROGRAM found in the environment, but not any commands in the system or user startup files that use the info_program function.

--interactive

-i

Force interactive behavior. This can be useful for running Octave via a remote shell command or inside an Emacs shell buffer. For another way to run Octave within Emacs, see Emacs.

--no-history

-H

Disable command-line history.

--no-init-file

Don't read the ~/.octaverc or .octaverc files.

--no-line-editing

Disable command-line editing.

--no-site-file

Don't read the site-wide octaverc file.

--norc

-f

Don't read any of the system or user initialization files at startup. This is equivalent to using both of the options --no-init-file and --no-site-file.

--path path

-p path

Specify the path to search for function files. The value of path specified on the command line will override any value of OCTAVE_PATH found in the environment, but not any commands in the system or user startup files that set the internal load path through one of the path functions.

--persist

Go to interactive mode after --eval or reading from a file named on the command line.

--silent

--quiet

-q

Don't print the usual greeting and version message at startup.

--traditional

--braindead

For compatibility with Matlab, set initial values for user-preferences to the following values

            PS1                             = ">> "
           PS2                             = ""
           beep_on_error                   = true
           crash_dumps_octave_core         = false
           default_save_options            = "-mat-binary"
           fixed_point_format              = true
           history_timestamp_format_string = "%%-- %D %I:%M %p --%%"
           page_screen_output              = false
           print_empty_dimensions          = false
    

and disable the following warnings

            Octave:fopen-file-in-path
           Octave:function-name-clash
           Octave:load-file-in-path
    

--verbose

-V

Turn on verbose output.

--version

-v

Print the program version number and exit.

file

Execute commands from file. Exit when done unless --persist is also specified.

Octave also includes several built-in variables that contain information about the command line, including the number of arguments and all of the options.

— Built-in Function: argv ()

Return the command line arguments passed to Octave. For example, if you invoked Octave using the command

          octave --no-line-editing --silent
    

argv would return a cell array of strings with the elements --no-line-editing and --silent.

If you write an executable Octave script, argv will return the list of arguments passed to the script. See Executable Octave Programs, for an example of how to create an executable Octave script.

— Built-in Function: program_name ()

Return the last component of of the value returned by program_invocation_name.

See also: program_invocation_name.

— Built-in Function: program_invocation_name ()

Return the name that was typed at the shell prompt to run Octave.

If executing a script from the command line (e.g., octave foo.m) or using an executable Octave script, the program name is set to the name of the script. See Executable Octave Programs, for an example of how to create an executable Octave script.

See also: program_name.

Here is an example of using these functions to reproduce Octave's command line.

     printf ("%s", program_name ());
    arg_list = argv ();
    for i = 1:nargin
      printf (" %s", arg_list{i});
    endfor
    printf ("\n");

See Index Expressions, for an explanation of how to properly index arrays of strings and substrings in Octave, and See Defining Functions, for information about the variable nargin.

Begin

Get help: help + whatever
Ex: help plot
help comma
help semicolon
More about comments for getting help.

Matrix
Identity 3x3 matrix: eye(3)
A 3x3 matrix: A = [ 1, 1, 2; 3, 5, 8; 13, 21, 34 ]
A random matrix w. coeffs. between 0 and 1: B = rand (3, 2)
To display B: B
Transpose: B'
Matrix arithmetics: 2*A, A*B, A'*A
Solve Linear System Ax=b: A\b

Integrating Differential Equations
To be continued.