I'm building a console application in Ruby. One of the things I'd like it to do is edit text files. It strikes me that the most reasonable course of action would be to launch whatever default editor the user has set up -- nano, vi, emacs... let the user decide. I'd like to pass it the name of the file that will be created/edited.
I've investigated various methods, including the backticks like so:
response = `nano *nameoffile*`
And I've also tried using the POpen4 Ruby gem, which also doesn't seem to do anything.
I suspect these methods are strictly for common, non-shell-type applications that immediately return a result, and editors like nano require a different technique? Your feedback is much appreciated!
Cheers,
Aaron.
You might want to take a look at interactive_editor, they do something like that.
Also you can use
system "nano #{your_file_name}"
There is a good discussion around using exec() or system() or backticks `` to launch interactive processes (like a text-editor)
See it here
It also has info if you want to go deeper into popen4 (which in fact does something, although not suited for all situations), such as the advantages and incovenients
Related
I've been wondering how I could do some of these cool customization options for the terminal on a Mac and I came across lolcat.
However, I can't seem to find an answer as to how to add this into my bashrc (FYI: I'm using zsh now just in case that makes a difference as to which file to add my customizations in) I have tried what many others have suggested, which was just typing zsh | lolcat into the terminal to get rainbow output in the current session, but I was wondering how I can have this every time I start a terminal session.
Also, I'm not sure if this is a bug or if there's something wrong with my terminal settings, but when I use a command with lolcat, I get an output like this:
karenlee#Karens-MBP ~ % Documents
Downloads
Library
Movies
Music
Pictures
Postman
Public
38;5;48m
karenlee#Karens-MBP ~ % 38;5;48m
The colors look right, but as you can see, when I type the ls command on the command line, it disappears and the output also gets messy. It also seems like there's extra lines of 38;5;48m which are appearing. And it also seemed like many of the gems that are installed with lolcat have deprecated; is there another alternative to lolcat that plays nicely with macOS Catalina?
I made a shell extension for the world's fastest website generator that I make called Nift. It has an easter egg where you can turn on lolcat output for most things with lolcat.on (after starting the shell with eg. nift sh). You will even get rainbow output when pressing tab to get possible completion options, I doubt you get that with any other suggested solutions.
The shell extension is for f++ which is the in-built scripting language, which has these functions and these types available. But anything it doesn't recognise is run as a system call using the (probably primary/default) shell on your machine (hence calling it a shell extension in REPL shell mode).
Nift will look for a version of lolcat installed on your machine and otherwise use an in-built version of it which should be the world's fastest (it's near identical to my c++ implementation lolcat-cc which is the world's fastest). I highly recommend installing lolcat-cc (or another version of lolcat) on top of Nift though as otherwise you are frequently running the ~5mb Nift binary for basically all system calls, instead of a <1mb binary for lolcat.
f++ is somewhat of an interesting scripting language as well. Take this script for example which creates and deletes 100k empty text files. On my machine this runs in ~3.5 seconds whereas this Bash script doing essentially the same thing takes more like 3 minutes!! Some of the cool things you might already notice from that f++ script is you can expand variables inside strings, you can define variables with types, you can expand variables in to multiple parameters with function calls, you can have LOTS more than 10k input parameters for function calls (should be able to have millions!).
You can find some more information about the Nift REPLs (including shortcuts for different platforms) here.
If you need to define shell variables (not through f++ but the underlying shell) then you will need to do blocks of code using the sys/system function. You can also do blocks of code for Lua(JIT) and ExprTk similarly as they are both embedded in to Nift. You can use both Lua and ExprTk with accessing/modifying f++ variables as well..
So to get this shell (extension). Install Nift through a package manager or clone, make and install off GitHub. Enter nift sh in to your terminal to start the Nift f++ shell extension, then enter lolcat.on to turn on rainbow output.
I just want to be able to run a python script from the interpreter, so that I can work on my changes to my script in notepad or other editor, save, and then interactively test changed code in the python interpreter.
Also, IDLE is not a solution. I'm operating on a government computer that is blocking the port it uses to communicate interaction between console and module.
To clear up any confusion, here's a demonstration of what I'm trying to do:
So, how do I do it?
EDIT:
Okay so I found a statement that does what I want. exec(open('dir').read()). The problem I think is that the directory I want to refer to contains periods. But I'm sure this will work, because open('dir').read() produces a string of the contents of a document specified, as long as I reference the likes of C:\myTest.py, and exec() obviously runs strings as input. So how can I reference files from the location I want?
Okay so the problem seems to be that Windows addresses often contain what python sees as 'unicode exits'. I'm not sure what they do or how they work, but I know they start with \ and are followed by a single letter and that there are enough of them to use up half the alphabet. There are a few solutions but only one is worth a damn for this application. I came across an operator that can be used in conjunction with strings, similarly to how + can be used to concatenate multiple strings, it seems r or R if you prefer (interestingly), can be used immediately before a string to tell the interpreter to take the string 'literally' as a string, and nothing else.
One would think that the quotes would be enough to express this, but they aren't and I'll probably eventually find out why. But for now, here's the answer to my question. I hope someone else finds it useful:
In plain text: >>> exec(open(R'C:\Users\First.Last\Desktop\myScript.py').read())
Open up irb and
type gets. It should work fine.
Then try system("choice /c YN") It should work as expected.
Now try gets again, it behaves oddly.
Can someone tell me why this is?
EDIT: For some clarification on the "odd" behavior, it allows me to type for gets, but doesn't show me the characters and I have to press the enter key twice.
Terminal input-output handling is dark and mysterious art. Anyone trying to make colorized output of bash work in windows PowerShell via ssh knows that. (And various shortcutting habits like Ctrl+Backspace only make things worse.)
One of the possible reasons for your problem is special characters handling. Every terminal out there can type characters in number of different modes, and it parses its own output in search for certain character sequences in order to toggle states.
F.e. here one can find ANSI escape code sequences, one of possible supported standards among different kind of terminals.
See there Esc[5;45m? That will make all the following output to blink on magenta background. And there is significantly more stuff like that out there.
So, the answer to your question taken literally is — your choice command messes something with output modes using special escape sequences, and ruby's gets breaks in that quirk special mode of terminal operation.
But more useful will be the link to HighLine gem documentation. Why one might want to implement platform-specific and obtrusive behavior when it is possible to implement the same with about 12 LOC? All the respect for the Gist goes to botimer, I've only stumbled into his code using search.
I must work with tcsh.
I am using an internal tool that provides basic completion for some of its commands.
I would like to extend the completion.
I mean that in future releases the default completion may evolve.
I tried something like this:
set def_cmpl = complete tool
complete tool $def_cmpl 'n/-l/(reg short long gui)/'
But I don't understand the result I get.
Indeed, the quotes inside $def_cmpl are doubled:
tcsh> complete tool
''n#-t#$script#'' n/-l/(reg short long gui)/'
I tried some tricks with echo, sed, etc. but I can't avoid those ''.
Could somebody help me?
Please don't say go on bash... The tool doesn't support it...
Finally, I did not find a solution to keep the data inside the script. So, the solution was to redirect the output of the complete command inside a file and then to append new lines to the file.
Background
Lately I've become a fanatic that everything I type while working on a computer should be compatible with "DRY". If there's anything I have to type more than once in any context, I want some kind of user-aware auto-complete option to do some of the work for me -- always -- no exceptions.
Having to work under Windows, I've looked at GUI solutions to make this insane goal a reality.
The (almost) optimal solution
If you have a moment, open up Firefox 3.0 and type a few keystrokes into the address bar. You will notice that it performs a kind of Incremental Autocomplete based on space-separated sub-strings of whatever you type. Another place in Firefox that does something similar is the about:config URL.
This is sub-optimal, because I don't want this in Firefox only. I want to use this everywhere.
The Question
Does anyone out there know of a widget or app that does nothing but insanely good incremental auto-complete that can be used as a general purpose "run everywhere" tool? Something that allows the user to: 1) maintain one or more "completion candidate files"; 2) pick one of those files as the source for Firefox 3.0 style completion; 3) return the result (or blank if the user canceled), and do those three things only?
Details
Here's how it should work:
STEP1: user saves or more csv file(s) (or other easy-edit format) somewhere in his hard-drive
STEP2: user creates a Windows Script Host script or a batch file (or whatever) instantiates the FilterAsYouType GUI
STEP3: user runs the script file, and the script file instantiates the GUI, telling it which CSV file to use as the source of all potential completions
STEP4: the user either chooses one of the completions, supplies his own text that is not in the list, or cancels out without supplying anything
STEP5: when the user is done the script saves the result to a variable and does something with it
Here is some pseudo-code for the script:
include "GenericTypeaheadWidget";
var gengui = new GenericTypaheadWidget('c:\docs\favorite_foods.csv');
var fave_food = gengui.get_user_input();
if(fave_food != ''){
alert('you chose '+fave_food+'!');
}
The rationale
The goal is to just have a way to always be able to do auto-completions from a list of arbitrary items, even if the list is a couple thousand items, and not have to rely on it being built into some IDE or standalone application that only accepts certain kinds of input or has an overly-complicated API relative to the simplicity of this task.
CSV (or text or sqlite database) would provide a way for me to self-generate "candidate lists" or "history logs" and then just use those logs as the source of the possible completions.
The disclaimer
I've tried several GUI "launcher" programs, command-line engines like power-shell and scripting shells, the regular plain old command-line history with varying degrees of satisfaction. The problem with these is they all do extra superfluous stuff like searching directories or built-in commands. I just want nothing but whatever is in the CSV file I happen to be pointing at.
I'm wondering if there is any simple tool that does nothing but what I'm describing above.
UPDATE: It looks like this question is very closely related to Graphical Command Shell, which captures the essential idea presented here.
You should really try Launchy - it's exactly what you're looking for, a "run anything" with intelligent autocompletion. It completely changes the way you interact with a Windows PC.
And it has open source-code, so you can borrow its autocompletion code if you want to roll your own interface.