smart-change-directory (scd)

Z shell function for visiting any directory in a unix shell, Vim or IPython.

scd is a Z shell (Zsh) script for changing to any directory with a few keystrokes. scd keeps history of the visited directories, which serves as an index of the known paths. The directory index is updated after every cd command in the shell and can be also filled manually by running scd -a. To switch to some directory, scd needs few fragments of the desired path to match with the index. A selection menu is displayed in case of several matches, with a preference given to recently visited paths. scd can define persistent aliases, which match only their target paths.

SYNOPSIS

scd [options] [pattern1 pattern2 ...]

PATTERNS

Patterns may use all zsh glob operators available with extendedglob option. Specified patterns must match the absolute path and at least one of them must match in the tail. Several special patterns are also recognized as follows:

^PAT

PAT must match at the beginning of the path, for example, "^/home"

PAT$

require PAT to match the end of the path, "man$"

./

match only subdirectories of the current directory

PAT:

require PAT to match over the tail component, "doc:", "re/doc:"

OPTIONS

-a, --add

add current or specified directories to the directory index. For file arguments add their containing paths.

--unindex

remove current or specified directories from the index.

-r, --recursive

apply options --add or --unindex recursively.

--alias=ALIAS

create alias for the current or specified directory and save it to ~/.scdalias.zsh.

--unalias

remove ALIAS definition for the current or specified directory from ~/.scdalias.zsh. Use "OLD" to purge aliases to non-existent directories.

-A, --all

display all directories even those excluded by patterns in ~/.scdignore. Disregard the unique matching for a directory alias and filtering of less likely paths.

-p, --push

use "pushd" to change to the target directory.

--list

show matching directories and exit.

-v, --verbose

display directory rank in the selection menu.

-h, --help

display this options summary and exit.

INSTALLATION

Unix shell

1. Make sure that Z shell is installed. On Linux it is usually the zsh package.

2. Copy or symlink the bin/scd script to some directory in the PATH.

3. Find out what shell is active for your account by running ps -p $$.

4. Edit the startup file for your shell and have it source the corresponding scd setup file from shellrcfiles as follows:

   • zsh

     # ~/.zshrc
     source ~/Software/smart-change-directory/shellrcfiles/zshrc_scd

     Note that scd aliases are named directories in Zsh and can be thus expanded as ~NAME in the shell. If you use the oh-my-zsh framework you may just activate the scd plugin instead.

   • bash

     # ~/.bashrc
     source ~/Software/smart-change-directory/shellrcfiles/bashrc_scd

   • tcsh

     # ~/.cshrc
     source ~/Software/smart-change-directory/shellrcfiles/tcshrc_scd

   • dash

     # add to ~/.profile or to the ${ENV} file
     . ~/Software/smart-change-directory/shellrcfiles/dashrc_scd

Examples

# Index recursively some paths for the very first run
scd -ar ~/Documents/

# Change to a directory path matching "doc"
scd doc

# Change to a path matching all of "a", "b" and "c"
scd a b c

# Change to a directory path that ends with "ts"
scd "ts$"

# Show selection menu and ranking of 20 most likely directories
scd -v

# Alias current directory as "xray"
scd --alias=xray

# Jump to a previously defined aliased directory
scd xray

Installation as Vim plugin

Please refer to https://github.com/pavoljuhas/scd.vim.

Installation as IPython extension

1. Copy or symlink ipython/ipy_scd.py to some directory in Python module path.

2. In IPython terminal session do %load_ext ipy_scd to define the %scd magic command. This also modifies the %cd, %pushd, %popd magics to add directories to the scd index. To load ipy_scd for every IPython session, modify .../profile_default/ipython_config.py so that it contains

   c.TerminalIPythonApp.extensions = ['ipy_scd']

3. If scd is not in the PATH, its location can be defined with

   import ipy_scd
   ipy_scd.scd_executable = '/path/to/scd'

Examples

# recursively index ~/.local/ and its subdirectories
%scd -ar ~/.local

# jump to the site-packages directory (if exists in ~/.local)
%scd site pack

FILES

~/.scdhistory

time-stamped index of visited directories.

~/.scdalias.zsh

scd-generated definitions of directory aliases.

~/.scdignore

glob patterns for paths to be ignored in the scd search, for example, /mnt/backup/*. The patterns are specified one per line and are matched assuming the extendedglob zsh option. Lines starting with "#" are skipped as comments. The .scdignore patterns are not applied in the --all mode.

ENVIRONMENT

SCD_HISTFILE

path to the scd index file (by default ~/.scdhistory).

SCD_HISTSIZE

maximum number of entries in the index (5000). Index is trimmed when it exceeds SCD_HISTSIZE by more than 20%.

SCD_MENUSIZE

maximum number of items for directory selection menu (20).

SCD_MEANLIFE

mean lifetime in seconds for exponential decay of directory likelihood (86400).

SCD_THRESHOLD

threshold for cumulative directory likelihood. Directories with a lower likelihood compared to the best match are excluded (0.005).

SCD_SCRIPT

command script file where scd writes the final cd command. This variable must be defined when scd runs in its own process rather than as a shell function. It is up to the scd caller to use the output in SCD_SCRIPT.