fc: Edit and Rerun Shell History Commands

Overview

`fc` stands for 'fix command' and helps you select a command from your shell history to open in your default editor or to rerun immediately without editing. This can save time during repetitive tasks or when correcting typos.

Key Features

Edit shell history commands
Rerun history commands without editing
Select and process specific ranges of commands
Specify a default editor

Key Options

The `fc` command offers various options to control how history is processed.

Behavior Control

Generated command:

Try combining the commands.

Description:

`fc` Executes the command.

Combine the above options to virtually execute commands with AI.

Usage Examples

Learn how to manage history and rerun commands through various examples of the `fc` command.

Edit and Rerun the Most Recent Command

fc

Opens the most recently executed command in the default editor (usually `vi`). After editing and saving, the command will be re-executed.

Edit Recent Command with a Specific Editor

fc -e nano

Uses the `nano` editor to edit and rerun the most recent command.

View the Last 5 Commands

fc -l -5

Displays a list of the last 5 executed commands with their numbers.

Edit a Specific Range of Commands

fc 100 105

Opens commands from history numbers 100 to 105 in the editor for modification and re-execution.

Rerun Previous Command (Without Editing)

fc -s

Immediately re-executes the most recently executed command without invoking an editor. The `-s` option suppresses editor invocation.

Rerun Command Starting with a Specific String

fc -s ssh

Finds and re-executes the most recent command starting with `ssh` without editing.

Substitute String in Previous Command and Rerun

fc -s old_string=new_string

Re-executes the most recent command after changing 'old_string' to 'new_string'. This is similar to the `^old_string^new_string^` shortcut.

Tips & Precautions

Tips and precautions to help you use the `fc` command more efficiently and safely.

Setting the Default Editor

You can specify the default editor that `fc` will use by setting the environment variables `$FCEDIT` or `$EDITOR`.

Example: export FCEDIT=nano
Priority: $FCEDIT takes precedence over $EDITOR.

Checking History Numbers

You can use the `history` command to view the current shell's history list and the number of each command. This is useful when specifying a particular command with `fc`.

Safe Re-execution

When re-executing complex commands, especially those involving pipes (|) or redirection (>, >>), it is safer to first open the command in `fc`'s editor to review and modify it. Be cautious with `fc -s` as it executes immediately without an editing step.