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Control-Y
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Control-Y is a common computer command. It is generated by holding Ctrl and pressing the Y key on most computer keyboards.
In most Windows applications this keyboard shortcut functions as Redo, reversing a previous Undo. In some programs such as Microsoft Office it repeats the previous action if it was something other than Undo.[1]
Apple Macintosh systems use ⌘ Command+⇧ Shift+Z for Redo.[2] In general a shortcut on Macintosh using ⌘ Command matches up with a shortcut on Windows using Ctrl, this is one of the most noticeable conflicts. Many programs (on all systems including Linux) support both Ctrl+Y and Ctrl+⇧ Shift+Z for Redo to resolve this conflict. But quite a few remain where only one or the other shortcut works.
Other uses
[edit]The OpenVMS operating system command-line uses Ctrl+Y as its "abort" character, stronger in effect than the ordinary Ctrl+C "interrupt" character.
Ctrl+Y deleted the current line in the WordStar word processor for CP/M and MS-DOS.[3] In the 1980s, many text editors and word processors mimicked the WordStar command set, making Ctrl+Y a common synonym for "delete line."
In Borland IDEs it also deletes the current line.
In emacs it does a paste action (known as "yank").[4] Emacs uses Ctrl+/ for Undo and Redo.
In vi and vim it scrolls the display up one line.[5]
In the pico and nano text editors this shortcut scrolls one page up.[6][7]
In SAP GUI it enters block-select mode.[citation needed]
See also
[edit]References
[edit]- ^ "Keyboard shortcuts in Word".
- ^ Apple Shortcut Key Standards
- ^ WordStar Reference Card. San Rafael, CA: MicroPro. June 1980 – via archive.org.
- ^ Yanking - GNU Emacs Manual
- ^ "vi(1p) - Linux manual page". man7.org. Scroll Backward by Line. Archived from the original on 2023-07-18. Retrieved 2023-09-09.
[count] <control>-Y: Display the line count lines before the first line currently displayed.
- ^ "U-M Information and Technology Services".
- ^ "Nano Keyboard Commands". Archived from the original on 2015-11-27. Retrieved 2015-12-09.
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Control-Y
View on Grokipediafrom Grokipedia
Control-Y, often stylized as Ctrl+Y, is a standard keyboard shortcut in computing that activates the "redo" command, allowing users to reverse the effects of the previous "undo" operation in most graphical user interfaces and applications.[1] This shortcut is generated by simultaneously pressing the Control key and the Y key on a keyboard, and it serves as the counterpart to Control-Z (Ctrl+Z), which performs the undo function.[2] Primarily associated with Windows operating systems and Microsoft software like Office suites, Control-Y enables efficient navigation through edit histories by reapplying actions that were recently undone, thereby streamlining workflows in text editing, graphic design, and data manipulation tasks.[1]
In broader contexts, the redo functionality invoked by Control-Y supports multiple levels of action reversal, depending on the application's implementation; for instance, repeated presses can redo a sequence of previously undone steps in tools like Microsoft Excel or Word.[1] Widely recognized in many productivity applications, variations exist across platforms and specialized software—for example, on macOS the equivalent redo shortcut is Command+Shift+Z, and in Adobe Illustrator, Ctrl+Y toggles between preview and outline views rather than performing a redo.[3][4]
Overview
Definition and generation
Control-Y is a keyboard shortcut generated by simultaneously pressing the Control (Ctrl) key and the Y key on standard computer keyboards.[5] This combination produces a control character input that applications interpret as a command signal rather than a printable letter. In the ASCII standard, Ctrl+Y corresponds to the End of Medium (EM) control character, with a decimal value of 25 and hexadecimal value of 19.[6] However, in modern graphical user interfaces (GUIs), the operating system or application typically intercepts this key combination at the hardware or driver level, preventing it from being transmitted as the raw ASCII character to the terminal or input stream.[7] This shortcut is primarily associated with English QWERTY keyboard layouts, where the Y key is positioned in the top row of the alphabetic section. In non-QWERTY layouts, such as AZERTY or QWERTZ, the physical position of the Y key may differ (e.g., swapped with Z in AZERTY), but the Ctrl modifier is applied to the key that generates the 'Y' character in the active layout.[8] Control-Y functions on various hardware platforms, including desktop and laptop keyboards with physical Ctrl and Y keys, as well as physical keyboards connected to mobile devices (e.g., via Bluetooth or USB) that support modifier keys like Ctrl for productivity apps or remote desktop sessions.[9] In many applications, this input serves as a redo command to reverse an undo action.[7]Common associations
Control-Y is primarily associated with the redo function in productivity software, where it reverses the action undone by Control-Z, allowing users to restore previously reversed changes in applications such as word processors, spreadsheets, and code editors.[1][2] This association stems from its role in maintaining a balanced edit history navigation, complementing the undo operation to support iterative workflows without permanent data loss.[10] The mnemonic reasoning behind assigning 'Y' to redo often relates to its position immediately adjacent to 'Z' on the QWERTY keyboard, creating a natural pairing for opposing actions that promotes efficient one-handed use near other editing shortcuts like cut (X) and copy (C).[11] As of 2025, Control-Y functions as the redo shortcut in the majority of Windows applications and many cross-platform tools, reflecting widespread adherence to Microsoft-influenced UI conventions that standardize keyboard interactions for consistency across software ecosystems.[10][12][13]Primary Usage
Redo functionality
In general computing environments, the redo functionality associated with Control-Y (Ctrl+Y) re-applies the most recently undone action when available, restoring the application's state from the undo stack to its prior condition before the undo operation. When no actions are pending in the redo stack, Ctrl+Y repeats the most recent non-undo action, such as pasting or applying a format, particularly in applications like Microsoft Office.[1][2] For example, if a text deletion is undone via Ctrl+Z, activating Ctrl+Y will re-execute that deletion. The typical workflow involves sequential interaction with the undo history: after one or more undos via Ctrl+Z, pressing Ctrl+Y once redoes the last undone action, and repeated presses continue forward through the stack of previously undone operations. This bidirectional navigation supports precise control over iterative modifications without permanent loss of recent states. It complements the undo operation by enabling recovery of intentionally reversed actions, as explored further in the relation to undo section.[1] At its core, redo implementation relies on an action stack or the command design pattern, a behavioral software architecture where each user action is encapsulated as a reversible command object that can be queued, executed, and unexecuted. In this pattern, commands are pushed onto an undo stack upon execution; undos pop and reverse them, transferring to a redo stack, from which redo operations pop and re-execute. This structure ensures actions are stored with both forward (execute/redo) and backward (undo) methods, facilitating reliable history management.[14][15] A key limitation of redo functionality is that the redo stack typically clears automatically upon any new action to avoid inconsistencies between the current state and pending redos; for instance, entering new text after an undo will discard the redo history, requiring users to re-perform those actions manually if needed. This design prevents branching histories that could complicate state synchronization. Despite such constraints, redo enhances editing efficiency by minimizing repetitive input and supporting fluid experimentation in workflows.[16][17]Relation to undo
Control-Y, as the redo shortcut, is inherently paired with Control-Z (undo) to enable bidirectional navigation through a document's edit history, forming a core mechanism for reversible operations in user interfaces. This pairing leverages the keyboard layout, with Z positioned for backward actions and Y as its complementary forward counterpart, allowing users to step back and forth efficiently without disrupting workflow. The design ensures that redo directly counters undo, maintaining a linear history stack where each action can be reversed or reapplied as needed.[18] Historically, Control-Z and Control-Y were developed in synergy to provide a robust safety net for user errors, enabling trial-and-error interactions without fear of permanent data loss. Early implementations, such as those in the Xerox PARC Bravo editor from 1974, introduced undo as a foundational feature, with redo emerging alongside it in subsequent systems like the Apple Lisa in 1983 to support iterative experimentation. A 1976 IBM research report emphasized the value of such mechanisms, noting that the ability to retract commands alleviates user distress and encourages confident exploration of software features, thereby reducing anxiety in creative tasks and promoting bolder innovation. This combined approach transformed user interfaces by mitigating the risks associated with interactive systems.[19][20] In terms of user experience, invoking undo with Control-Z typically clears the forward history in the redo stack, positioning Control-Y as the exclusive means to recover previously undone actions and thereby avoiding potential infinite loops in state management. This behavior ensures system stability by preventing conflicting histories from accumulating. For edge cases, multiple successive undos build a redo queue accessible via repeated Control-Y presses, but any new user input—such as typing or editing—invalidates and clears the redo queue to maintain a coherent current state.[21] The psychological impact of this undo-redo interplay is significant, fostering a sense of reversibility and control during experimentation. This bidirectional safety mechanism has become a staple in modern software, enhancing overall usability.[20]Variations Across Platforms
Operating systems
In Windows, Ctrl+Y serves as the native redo shortcut for reversing the most recent undo action (Ctrl+Z) across the operating system, including in File Explorer for file operations such as renaming or moving items.[7] This functionality has been integrated since Windows 95, where the Explorer shell introduced multi-level undo and redo support for enhanced file management. On macOS, the default redo shortcut is Command+Shift+Z in system applications like Finder and TextEdit, allowing users to reapply undone actions such as text edits or file modifications.[3] However, Ctrl+Y functions differently at the system level, primarily in Terminal and emulator contexts where it pastes the most recently "killed" (cut) text from the readline buffer, a behavior inherited from Unix-like shells. This distinction reflects a historical evolution from early Macintosh shortcuts, which prioritized Command-key combinations for GUI interactions starting with System 7 in 1991, gradually standardizing redo as Command+Shift+Z to avoid conflicts with Emacs-style bindings. Linux implementations of Ctrl+Y vary by desktop environment and application context, with no universal system-wide default due to the modular nature of distributions. In GNOME (used in Ubuntu and Fedora), the redo shortcut in the Nautilus file manager is Ctrl+Shift+Z for operations like folder navigation or deletions, aligning with broader GNOME conventions. In KDE Plasma environments, the redo shortcut in the Dolphin file manager is Ctrl+Shift+Z, consistent with many Qt-based applications. Conversely, in terminal emulators running Bash or similar shells, Ctrl+Y typically yanks (pastes) previously killed text from the input buffer, rather than suspending processes or acting as end-of-file, though delayed suspend can be bound to it in some configurations. On mobile operating systems like Android and iOS, Ctrl+Y lacks native support on virtual keyboards but is recognized in productivity applications (e.g., Google Docs) when using external Bluetooth keyboards, where it performs redo for text editing.[22] Chrome OS, built on a Linux kernel, aligns closely with Windows conventions by using Ctrl+Y as the redo shortcut system-wide, including in the Files app and web-based tools, to facilitate cross-platform consistency for users transitioning from desktop environments.[23] Cross-platform shortcut handling, including Ctrl+Y, is influenced by display server protocols: X11 propagates keyboard events globally, allowing applications to intercept and process combinations like Ctrl+Y for redo in window managers, while Wayland emphasizes per-application input isolation for improved security, requiring compositors (e.g., Mutter in GNOME) to route shortcuts via input method protocols without legacy X11 grabs.Specific applications
In text editors and integrated development environments (IDEs), Control-Y implementations vary significantly from the standard redo function. In Microsoft Office applications such as Word and Excel, Control-Y serves to redo the last undone action or repeat the previous command, a feature consistent across these tools for efficient workflow management.[24][25] This shortcut has been a core part of Office's editing paradigm, enabling users to reverse undos or duplicate actions like formatting or insertions without menu navigation. In contrast, the Vim text editor assigns Control-Y to scrolling the screen upward by one line without moving the cursor, prioritizing view manipulation over action reversal in its modal editing system. This non-redo usage highlights Vim's focus on precise text navigation, where scrolling commands like Control-Y complement cursor movements. Graphics software often deviates from conventional redo bindings to accommodate specialized preview functions, leading to potential conflicts. In Adobe Illustrator, Control-Y toggles between Outline view—which displays paths as wireframes for precise editing—and the standard Preview mode, allowing designers to switch visualizations rapidly during artwork creation.[4] Similarly, in Adobe Photoshop, Control-Y activates or deactivates Proof Colors, a preview mode that simulates output conditions like grayscale or color profiles to ensure print fidelity. These assignments override the typical redo behavior, requiring users to remap shortcuts if they rely on Control-Y for action repetition, as the preview toggles can inadvertently disrupt editing history. Web browsers generally align Control-Y with redo functionality within editable contexts like forms or rich text areas, but extensions and legacy features introduce variability. In Google Chrome and Mozilla Firefox, pressing Control-Y redoes the last undone typing or formatting change in input fields, supporting standard web editing conventions across sites like Google Docs or email composers.[26][22] However, browser extensions or custom scripts may intercept the shortcut, causing conflicts. Other applications exhibit unique bindings that diverge entirely from redo semantics. In the Emacs editor, Control-Y performs a "yank" operation, inserting the most recent killed (copied or cut) text from the kill ring at the cursor position, emphasizing Emacs's ring-based clipboard management.[27] In command-line terminals using shells like Bash, Control-Y yanks (pastes) the last deleted text segment, such as content cut with Control-U or Control-K, facilitating quick line editing without mouse interaction.[28] To mitigate conflicts arising from these diverse implementations, most modern applications provide options for shortcut customization through preferences or dedicated dialogs. For instance, Adobe Creative Cloud apps allow editing of keyboard shortcuts via the Keyboard Shortcuts menu, enabling users to reassign Control-Y to redo if needed. Similarly, IDEs like Vim and Emacs support configuration files (e.g., .vimrc or .emacs) for remapping keys, while system-level tools in Windows, such as PowerToys Keyboard Manager, permit application-specific overrides to harmonize behaviors across software.[29] This flexibility ensures accessibility and productivity in multi-application environments.History and Standardization
Origins in early software
The Control-Y shortcut emerged in the context of terminal-based computing during the 1960s and 1970s, when ASCII control codes defined combinations like Ctrl-Y (ASCII 25, End of Medium) for basic terminal operations in teletype and early computer systems. In UNIX and BSD environments of that era, such codes were primarily used for low-level input handling and were often left unused in command-line interfaces or assigned to minor functions like signal handling, predating more complex editor behaviors.[30] A seminal early use appeared in the vi text editor, created in 1976 by Bill Joy as part of the Berkeley Software Distribution for UNIX. In vi's normal mode, Ctrl-Y scrolls the screen upward by one line, enabling users to preview additional preceding text without repositioning the cursor or disrupting editing flow—this function reflected the constraints of character-based displays and influenced scrolling mechanics in subsequent terminal editors. By the late 1970s, Ctrl-Y gained prominence in word processing software running on CP/M and early MS-DOS systems. In WordStar, released in 1978 by MicroPro International, Ctrl-Y served to delete the entire current line where the cursor was positioned, a concise command that streamlined text removal in non-GUI environments and was widely emulated in 1980s text editors due to WordStar's market dominance.[31] These terminal-era assignments laid groundwork for Ctrl-Y's evolution, though its role shifted with the advent of graphical interfaces like the Xerox Alto's experimental GUI in 1973, where keyboard controls complemented mouse interactions for editing tasks. By the mid-1980s, paired undo/redo mechanisms in systems such as the Apple Macintosh (1984) began standardizing forward-reverse actions, with Ctrl-Y (or equivalents) emerging as the "forward" counterpart in Windows environments around 1990 to maintain proximity to Ctrl-Z on the keyboard layout.[32]Adoption in modern interfaces
The adoption of Control-Y (or its platform equivalents like Command-Y on macOS) as a redo shortcut solidified in the 1990s through key standardization efforts by major operating system developers. Microsoft's interface guidelines for Windows, beginning with early versions in the 1990s, established Ctrl+Y as the standard for redoing actions in applications, aligning it with the broader API for common editing operations. Similarly, Apple's 1992 Macintosh Human Interface Guidelines described the Undo command (Command-Z) as toggling to Redo after an undo is performed, without specifying a separate shortcut. Subsequent guidelines established Command-Shift-Z as the Redo equivalent.[33] These codifications influenced countless applications, promoting a uniform user experience for reversing undos in text editing, graphics, and productivity tools. Cross-platform frameworks further propagated Control-Y to diverse ecosystems starting in the 1990s. The Qt framework, widely used for developing applications on Linux, Windows, and other platforms, incorporates Ctrl+Y as the default redo shortcut in its editing components on Windows and Linux (with Command-Shift-Z on macOS), enabling seamless integration in open-source software.[34] On Linux, while some toolkits like GTK favor Ctrl+Shift+Z, Qt's influence ensured Control-Y's presence in many cross-platform apps, such as KDE-based editors. In the 2010s, web browsers advanced this adoption by implementing Ctrl+Y for redo operations in contenteditable HTML elements, as seen in major browsers like Chrome and Firefox.[35] In the 21st century, Control-Y's reach expanded to mobile and cloud environments, adapting to touch interfaces while preserving core functionality. On iOS and Android, gesture equivalents emerged as alternatives; Apple's Human Interface Guidelines recommend three-finger swipes or device shakes for undo/redo, effectively mirroring Ctrl+Y's role in apps like Notes and Pages since the 2010s.[36] Cloud-based tools like Google Docs, launched in 2006, support Ctrl+Shift+Z for redo to ensure compatibility across desktop and mobile users in real-time workflows.[22] This widespread implementation reflects high adoption rates in contemporary desktop software, with usability analyses indicating near-universal support in productivity suites while legacy systems like mainframes remain unaffected due to their non-graphical interfaces.Alternative and Conflicting Uses
Specialized software behaviors
In command-line interfaces such as Bash and Zsh, Control-Y serves as the yank command, which retrieves and inserts the most recently killed (deleted) text back into the input buffer at the cursor position, providing a way to recover previously removed content during line editing. This behavior stems from the Readline library used by Bash, where killing text with commands like Control-K stores it in a kill ring for later yanking, enhancing interactive editing efficiency in terminals. In media editing software, Final Cut Pro on macOS assigns Control-Y to toggle the Skimmer Info overlay in the browser view, displaying metadata such as keywords, ratings, and analysis details for the clip under the skimmer without altering the primary timeline workflow.[37] This specialized function supports quick inspection of clip properties during skimming, distinct from standard undo/redo operations.[38] In simulation games like Microsoft Flight Simulator 2020 and 2024, Control-Y has non-redo mappings. In Microsoft Flight Simulator 2020, Control-Y performs the redo function when Developer Mode is enabled. In Microsoft Flight Simulator 2024, Control-Y sets the condition lever to high idle in power management contexts for supported aircraft models.[39][40] When Control-Y conflicts with application-specific bindings, users on Windows can resolve issues by remapping keys using AutoHotkey, a scripting tool that allows custom hotkeys like redirecting Control-Y to alternative actions via simple syntax such as^y::Send {SomeOtherKey} in a .ahk script.[41] This approach enables personalized overrides without altering core software configurations, commonly applied in environments with overlapping shortcuts.[42]