Shell context helper for saving, recalling, and executing information from a persistent dictionary.
Setting environment variables and aliases (.bashrc, .cshrc, etc.)
is useful when you have an established workflow with known common actions.
This program is for discovering what that workflow should be, when the needed
working directories and commands are not fully known just yet. All shell
instances have access to the work-in-progress context dictionary.
The ctx command is the entry into the program. It behaves like a dictionary
that can get/set/delete keys and values.
$ ctx set x 123
$ ctx get x
123
$ ctx del x
It can be used for storing a long directory for later use:
$ cd /very/long/directory/to/type/manually
$ ctx set project `pwd`
$ cd "`ctx get project`"
It can store long commands for later use:
$ ctx set server '/usr/bin/python3 -m http.server'
$ ctx shell server
Serving HTTP on 0.0.0.0 port 8000 (http://0.0.0.0:8000/) ...
It can also save and load environment variables:
$ ctx set mypath $PATH
$ export PATH="`ctx get mypath`"
By default, ctx shows the current context dictionary and the
sorted timestamped (newest on top) entries:
$ ctx
Using context main
There are 2 entries.
2020-01-01T23:24:40.893719 server = python3 -m http.server
2020-01-01T23:07:57.792251 home = /home/serwy
copy - copies a key, updates timestamp
$ ctx copy home home2
rename - renames a key, preserves timestamp
$ ctx rename home2 home3
items - provides a sort-by-timestamp display of key-values
$ ctx items
home=/home/serwy
server=python3 -m http.server
keys - provides a list of keys
$ ctx keys
home
server
log - print out a log of changes to the context dictionary
$ ctx log
['2020-01-01T22:51:50.180685', 'set', 'home', '/home/serwy']
['2020-01-01T22:52:01.008981', 'copy', 'home', 'home2']
['2020-01-01T22:52:08.194826', 'rename', 'home2', 'home3']
switch - switch the context dictionary, or print a list.
New contexts may be created this way.
The context dictionary can be chained together using '+' and will show a
merged dictionary, with changes applied to the first name.
$ ctx switch dev
switching to "dev" from "main"
$ ctx switch
* dev
main
$ ctx switch main+dev
switching to "main+dev" from "dev"
shell - uses the key as a command, and values are treated as
additional keys. The command string is passed to a shell.
$ ctx set port 9999
$ ctx shell server port
Serving HTTP on 0.0.0.0 port 9999 (http://0.0.0.0:9999/) ...
dryshell - prints the command passed to the shell without executing
$ ctx dryshell server port
dryrun shell command: python3 -m http.server 9999
exec - uses the key to get the executable, and the additional arguments
are passed directly to the executable. This is like an alias.
$ ctx exec server 9999
Serving HTTP on 0.0.0.0 port 9999 (http://0.0.0.0:9999/) ...
dryexec - prints the arguments passed to the executable without executing.
$ ctx dryexec server 9999
dryrun exec command: ['python3', '-m', 'http.server', '9999']
set - set a key to a value
$ ctx set keyname value
get - print the value for the given key
$ ctx get server
python3 -m http.server
del - delete a key
$ ctx del keyname
setpath - add the present working directory to the value when setting
the given key
$ ctx setpath keyname .bashrc
keyname=/home/serwy/.bashrc
args - print out the arguments as seen by the program, quoted. This
is useful when debugging argument quoting errors.
$ ctx args some arguments "kept together"
sys.argv[:]
0 = '/home/serwy/.local/bin/ctx'
1 = 'args'
2 = 'some'
3 = 'arguments'
4 = 'kept together'
entry - auto-increment the maximum suffix for a key before setting.
This is useful for storing quick notes.
$ ctx entry _note This is an observation
_note_001=This is an observation
$ ctx entry _note system A depends on system B
_note_002=system A depends on system B
now - prints out the iso8601 time, filesystem safe.
This is useful for quickly appending a suffix to a file
$ ctx now
2020-01-01T193048.465660
$ cp myfile.txt ~/backup/myfile.txt_`ctx now`
update - opens a given file for loading key=value data. Use a
hyphen to read from stdin.
$ ctx switch env
$ env | ctx update -
$ ctx
Using context env
There are 6 entries.
2020-01-01T17:06:10.234052 _ = /usr/bin/env
2020-01-01T17:06:10.234040 PATH = /home/serwy/.local/bin:/usr/local/bin:/usr/bin
2020-01-01T17:06:10.234038 LC_ALL = en_US.UTF-8
2020-01-01T17:06:10.234028 DISPLAY = :0
2020-01-01T17:06:10.234012 HOME = /home/serwy
2020-01-01T17:06:10.233881 SHELL = /bin/bash
waitpid - waits for a PID to finish before exiting, possible displaying a message box.
# assume PID 5417 is a long-running process
$ ctx waitpid 5417 [message]
message - displays a graphical message box with a message, along with PID,
start time, and window elapsed time.
$ ctx message Hello World # Tkinter window appears
The active context may be forced by setting the CTX_NAME environment variable.
This is useful when needing to dedicate a terminal to a particular context.
A flag to increase verbosity. It is an integer value of 0, 1, or more.
If undefined, it defaults to 0.
Set the directory containing the dictionaries and logs. If unset,
it defaults to ~/.ctx/.
The context dictionaries are stored in ~/.ctx/
The .json files are the context dictionaries.
The .log files are the change logs.
The _name.txt file contains the name of the active context.
If missing, defaults to main.
Ensure that the ctx script can be found on your system PATH,
e.g. ~/.local/bin.
pip3 install shellctx
or
python3 setup.py install
If you just want the script directly, you can download and copy
shellctx/ctx.py as ctx somewhere on your $PATH and apply chmod +x.
The direct link is: https://raw.githubusercontent.com/serwy/shellctx/latest/shellctx/ctx.py
curl https://raw.githubusercontent.com/serwy/shellctx/latest/shellctx/ctx.py > ctx
chmod +x ctx
Licensed under the GNU General Public License, Version 3.0