cd by jumping (cjump)

Boost productivity by quickly and deterministically jumping to predefined paths and their subdirectories (or deeper subdirectories) using aliases.

Inspired by experience working on enormous commercial codebases.

As aliases are predefined, there is no uncertainty as to where an alias will jump to, because cjump doesn't care about usage frequencies like some tools do. This could be an upside or a downside, depending on your use case or habit.

Example

You have these long paths that you frequently work with:

• ~/projects/myos/kernel/mem
• ~/music/classical/orchestra/beethoven/symphonies
• ~/music/classical/orchestra/dvorak/symphonies

And you want to jump to any of them swiftly without hesitation and breaking your flow.

First, define aliases myos and orch

$ cjump alias myos ~/projects/myos
$ cjump alias orch ~/music/classical/orchestra

Now jump from anywhere to the the directories defined by these aliases:

$ cj myos
$ pwd
~/projects/myos
$ cj orch
$ pwd
~/music/classical/orchestra

The cj myos makes you jump from anywhere to ~/projects/myos, while cj orch jumps to ~/music/classical/orchestra.

That's not it. Try this:

$ cj myos mem
$ pwd
~/projects/myos/kernel/mem

Notice that mem is a sub-subdirectory of myos. The cjump script is able to search deeper beyond subdirectory level as illustrated below:

 Target:        ~/ projects / myos / kernel / mem
                ^^^^^^^^^^^^^^^^^^            ^^^
Command:   cj          myos                   mem

Here myos is the predefined alias, but mem does not need to be predefined.

Also, when multiple matches are found:

$ cj orch symphonies
Multiple matches found:

  (1) /home/me/music/classical/orchestra/beethoven/symphonies
  (2) /home/me/music/classical/orchestra/dvorak/symphonies

Which path to jump to?

Simply reply 1 or 2 in this case to pick the path you want to jump to.

Installation

1. Copy the content of cjump.sh to ~/.bashrc or ~/.zshrc.
2. Place cjump (the Python script) to somewhere in $PATH.

Description

cjump itself is a Python script that you can call directly, but it will not perform any jumps. The cj function is what you should use to perform the actual jumps. This shell function is needed because there is no way for a child process to modify the working directory of the parent process, and so the Python script cannot change the working directory of the interactive shell you're in.

These are the common operations:

Operation	Command
Jump to an aliased path	cj ALIASNAME
Jump to a subdirectory under an aliased path	cj ALIASNAME SUBDIR SUBSUBDIR ...
Jump to a subdirectory under the current directory	cj . SUBDIR SUBSUBDIR...
Define an alias	cjump alias ALIASNAME PATH
Undefine an alias	cjump unalias ALIASNAME
Print an alias's path	cjump alias ALIASNAME
Print all aliases	cjump alias or just cj

Upon running cjump, the the alias database ~/.cjump/alias will be created. This is the only file created by cjump.

To change the subdirectory search depth, change the value of CJUMP_DEPTH. Its value defaults to 4. Be careful when increasing this value: cjump can take a long time to search for subdirectories and return results.

Requirements

Bash or zsh on macOS or Linux. Python 2 or 3 is required.

Performance

The act of jumping is very fast. When used on *nix systems, it doesn't spawn any subshell or subprocess unless it's searching for deeper subdirectories.

The search for deeper subdirectories can be slow if you have a huge number of nested files and directories.