Scoroncocolo

Fish Autosuggestion

Perhaps the biggest difference between Fish and it's two primary competitors Bash and zsh is that Fish features autosuggestion right out of the box while the other two Command Line Shells require plugins and/or configuration scripts to achieve this functionality

Once you start typing the fist letter of a command at the prompt Fish will attempt to complete the command for you and shade its guess at what you wanted in grey/teal letters and you can accept the suggestion by hitting your right arrow key or you can have Fish show all other suggestions (if there are any) by hitting your Tab key allowing you to highlight the choices thus presented with your arrow keys
And once you have decided on one of the choices highlight it and hit the Enter/Return key to choose it then hit Enter again to execute the command

Fish Syntax Highlighting

Another outstanding, game-changing difference between Fish and its comptitors is that in Fish invalid commands or misspelled commands are highlighted in red while valid commands turn green, blue or a blue-ish teal color depending on your Fish set-up and are underlined

This underling of valid paths is a wonderful Fish-only feature

Web-Based Customization

Unlike any other Command Line Shell, Fish allows you to use web-based customization
Just run fish_config or fish_config browse and Fish will open up a page in your default browser that shows your current settings for Colors, Prompt, Functions, Variables, History and Bindings and you can change any of those settings right there on the web page
The web page allows you to see how it will look on your console before you make the changes

Command Line Based Customization

You can use fish_config command to customize your fish shell. To customize your prompt, you can use fish_config prompt show command to get all the prompts, and based on your choice, you can use fish_config prompt save to save the prompt. You can also choose and update themes with the theme sub-command. For example, to show all the themes, you can use fish_config theme list to see a long list of themes
Preview a specific theme run fish_config theme show theme-name
Apply and save a theme fish_config theme choose theme-name
Apply the chosen theme to all future sessions by following it with save: fish_config theme save
To see your current theme type fish_config theme show

Navigating in Fish

Fish features built-in keybindings to help you move back and forth through your directory history

You can move backward through directories/folders that you've cd to by holding down the opt/alt key and using your left arrow key and then hit enter when one shows up yo want to visit again
And you can move forward through the list using your right arrow key

But one of the neatest ways to navigate in Fish is to use the command cdh to view a list of your cd history and then type a directory's corresponding number or letter and Bam! you're there!

You can also move backward by running the command prevd and forward by typing nextd

• prevd or (opt/alt+left arrow) - takes you to the previous directory
• nextd or (opt/alt+right arrow) - takes you to the next directory
• dirh (opt/alt+d) - shows a list of the recently visited directories
• cdh - allows you to quickly jump to any recently visited directory using letter or number shortcuts

Straying from the Path

In both the Bash and zsh shell rather than having to enter a long path name to get to a directory/folder, you can set a variable to represent the path to that directory by running DIR1="/Users/stevenhenderson/Desktop/Websites/commandline" for instance so that in order to cd to that directory you simply have to type cd $DIR1 and BAM! you're there

You can do that in the Fish shell too but the syntax is a little different
In fish you would need to run set DIR1 /Users/stevenhenderson/Desktop/Websites/commandline with no equal signs or parenthesis

So now if I wanted a list of all the files in that directory I could run ls $DIR1

You can define the path to yet another directory in Bash by running dir2="/Users/stevenhenderson/Desktop/Websites/fish"> and hit the Enter key or in Fish with set dir2 /Users/stevenhenderson/Desktop/Websites/fish and hit Enter/Return

Now no matter where you are in the Terminal you are you no longer need to use the complete path to cd into or work with files in those two directories/folders because the paths to those folders now have the shortcut/variable $DIR1 and $dir2 (just don't forget to use the dollar sign)

Varible Path in Bosh and zsh

• DIR1="/Users/stevenhenderson/Desktop/Websites/commandline"
• dir2="/Users/stevenhenderson/Desktop/Websites/fish"

Varible Path in Fish

• set DIR1 /Users/stevenhenderson/Desktop/Websites/commandline
• set dir1 /Users/stevenhenderson/Desktop/Websites/fish

This little variable trick works great in all three of the most common Command Line shells - Base zsh and Fish but it is only temporary and once you log out of the current session all three shells "forget" your handy path variables

To make these variables permanent in Bosh and zsh you would need to edit their config files which isn't all that scary of difficult but with Fish you don't have to dig into the guts of the shell

Make Fish Variables Permanent

Universal variables are unique to the fish shell. They are automatically saved and shared across all future shell sessions without you having to modify any configuration files

set -Ux VARIABLE_NAME value
-U makes the variable universal (persistent across reboots)
-x exports it as an environment variable to child processes
set -Ux DIR1 /Users/stevenhenderson/Desktop/Websites/commandline
set -Ux dir1 /Users/stevenhenderson/Desktop/Websites/fish

Fast Fish Facts

After installing fish your default shell will not be changed. To make Fish run type fish and to make fish your login shell after the installation, run: chsh -s /usr/local/bin/fish

To have the fish shell show a list of command flags (options/switches/modifiers), type a space then a dash (-) after any command like the ls (list command) for instance and press the Tab key

In fish shell, you can use fish -P or fish --private command to enter private mode. In private mode, your shell history will not be saved
Just type exit to move out of private mode

To quickly move to your Home Directory type cd and the symbol that is called tilde or cd ~

To move quickly to the root directory type cd /

cd .. to go to the parent of your current folder
cd ~ or just cd to jump back to your user’s home directory
cd / to go to the very top of your file system
cd ../.. to move up two levels
cd ../../.. to jump up three levels from your current location

• mkdir Data Makes a new, empty folder/directory named Data
• touch dog.txt Creates a new empty file named dog.txt
• pwd prints the path of the directory you are currently in
• ls lists all files in the current directory/folder
• ls -a list all files including hidden files
• ls -l long listing of all files showing owner, size and time last edited
• ls -R Recursive: Lists everything in the current folder and all subfolders
• ls .. list the contents of the parent directory one level above
• mv oldname.txt newname.txt renames files
• rm filename.txt (remove) permanetly deletes files (caution there be dragons)    there is no cmd + Z or undo
• rm -r DeadFolder remove/delete a directory/folder and all of its contents (files and sub-directories) permenatly
• cat AnyFile.txt prints out the entire text of the file
• head AnyFile.txt prints the first 10 lines of specified file
• tail AnyFile.txt prints the last 10 lines of specified file
• echo "Arf! Arf!" > dog.txt replaces any existing text with Arf Arf
• echo "Arf! Arf! Arf!" >> dog.txt adds text below existing text on dog.txt
• cp copies files or folders from one location to another
• say "Everything not forbidden is compulsory" hear your machine speak to you
• say -f filename.txt Reads the contents of a specific text file aloud
• history lists a history of your last 16 (in ZSH/macOS) commands
• history 5 lists your last 5 commands (specify any number you want) and you can use your up arrow to bring them to the command prompt
• open -a "Sublime Text" dog.txt will open the file in Sublime Text (substitute your code editor) if it is installed on your machine
• Command + K Clears the console's screen
• Control + Z to pause a process and put it in the background; you can resume it later with the fg command

Here's a link to my Command Line page

Scoroncocolo

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