If I accidentally entered a typo into a command prompt questionnaire, is there a way to go backwards and edit that input?
For example, when I run npm init, I'm given a bunch questions. If I accidentally write a typo in the package name field and press enter, the questionaire moves on to version:. Is there a way to quickly go back to package name and fix my typo?
My experience with the terminal and npm is limited, but I found out that you cannot undo a command line. However, I'm wonder if you CAN undo an answer to a command prompt, since this is a little different- The command hasn't really run yet until all the prompts are done.
Sat Apr 27 npm Dashie$ npm init
This utility will walk you through creating a package.json file.
It only covers the most common items, and tries to guess sensible defaults.
See `npm help json` for definitive documentation on these fields
and exactly what they do.
Use `npm install <pkg>` afterwards to install a package and
save it as a dependency in the package.json file.
Press ^C at any time to quit.
package name: (npm) oops-typo
version: (1.0.0)
An undo functionality like you are describing would have to be implemented by the developers of the cli tool you are using (in this case, npm).
I think the best I can offer as a means to fix your mistake on the command line, without having to open an editor and modify the package.json file from there, is to use the json npm package.
So in the particular case displayed in your question, you would keep going with the install and afterwards you could simply do:
$ npm i -g json
$ json -I -f package.json -e "this.name='your package name'"
You can edit the package name in the package.json file created when you use init.
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I decided recently that I want to start learning to code. I chose python as my first language because of it's versatility and Open Source connections. Now, of course to learn any programming language, first you have to be able to practice with it by writing code and running it.
I have Python beginner tutorials I am using but as soon as I got to the point where I wanted to run a simple Hello World message, I couldn't figure out how to get my document to actually RUN. I downloaded LiClipse with the hopes of using PyDev. I read that you can run a code directly from PyDev.
Wow, what a confusing mess! I downloaded the instant install version of LiClipse and I had to manually update the pip because it was out of date and that took an hour of research all on it's own to figure out how to do it.
Now that I have the interpreter set up correctly with the most recent pip...(I THINK), when I try to run any code I write, it doesn't let me. It wants me to save it first, which of course is quite logical. But when I try to save it, it says there is no folders to save to. How can there be no folders? I have been reading the install help, but it doesn't say anything about this issue. Or maybe it did explain how to fix this issue and I simply didn't understand all the jargon included in the configuration documentation. It kept instructing me to do technical things I couldn't understand.
Can anyone tell me what is going on? Shouldn't this all be ready to go when I used the "instant install" ?? I am just a beginner here, I don't know all this technical installation jargon. If anyone can help me get this setup, please let me know.
I really want to start learning. But I can't if I don't have the right tools.
Yeah, the technical jargon can be really confusing in the beginning. I've never heard of LiClipse but I can give you a few tips to get started:
Use a good IDE or Editor. For beginning VsCode with the Python PlugIn is quite good. You can also use PyCharm (the free version is enough) but that IDE is quite confusing.
Get comfortable with the commandline. On Windows you can invoke Python by running py on Linux with python3. You open the commandline on Windows by opening the startmenu, entering cmd and hitting enter.
You will have to make sure Python is in your "PATH" enviroment variable. That is a variable telling the Operating System where to find your programms. It should have asked you whether you want to add Python to your PATH during the install.
You run your python programm by saving it as a .py file and running py <filename.py> or python3 <filename.py> on Windows or linux respectively. You have to be in the directory where you saved your file of course.
I hope I could help you. Please mark this answer as accepted if it did answer your question or helped you with your issue.
I want to start by saying I'm mainly experienced in C & C++, not Python, but with programming in general many of the concepts carry over. I also don't have enough rep to comment, or I'd ask for some clarification on how familiar you are with the commandline.
I'm going to assume you're on Windows since you didn't mention the platform.
I wrote this like a tutorial, because I found those to be very helpful when I first started programming.
I can't recommend this enough, start off by using the commandline!
I think you complicated things more by searching for a text editor that can also run code. In order to get something like that working for your setup you need to know what's happening behind-the-scenes first.
Once you have a grasp of how to write & execute Python code, then you can move on to an IDE or advanced text editor like Visual Studio Code or LiClipse with confidence.
R+Click on the Start Menu, then click on Windows PowerShell to open a terminal.
Take a moment to note the filepath shown before the blinking cursor.
This is known as the Working Directory, which works similar to how the file explorer only allows you to "view" one directory at any given time; You can open multiple explorer windows side-by-side, but you can't view multiple directories at the same time in a single window.
You can run commands by typing them and pressing Enter.
You can also use the Tab key to autocomplete things like directory/file names, commands, etc. after typing a few characters.
Now let's create a workspace directory for your first project.
This can be anywhere that you choose, but for the sake of simplicity I'll be using my User directory which is usually where PowerShell will start by default.
To create a new directory named _workspace, use the mkdir (Make Directory) command like so:
mkdir _workspace
Now let's change our working directory to _workspace by using the cd (Change Directory) command like so:
cd _workspace
This directory is empty, but if you want to view the contents of a directory you can use the ls (List Directory) command:
ls
Since this is an empty directory, nothing will happen.
Next, we'll create a Python script file using the touch command, which creates empty files:
touch HelloWorld.py
Now that we have a script file, open HelloWorld.py in Notepad by running this command:
notepad HelloWorld.py
If you use a dark desktop theme, now is the time when your retinas may be seared out by the intensity of Notepad's white color scheme.
Now, let's add the code to print "Hello World!" in Python:
print("Hello World!")
Once you're done, you can save & close Notepad to save your retinas.
Now it's time to run the program! In the PowerShell window, enter this command:
py HelloWorld.py
which will show:
Hello World!
If you see an error saying this:
The term 'py' is not recognized as the name of a cmdlet, function, script file, or operable program.
You should re-install Python and make sure you check this box in the installer:
After re-installing Python and checking the Add to PATH box, close and reopen the PowerShell window, enter the cd _workspace command again, followed by py HelloWorld.py, which should be successful this time.
I hope I could be of some help, if so, I'd greatly appreciate marking this answer as accepted so I can write comments. Happy coding!
If you are using Linux following will work.
Install python3 first (Its better to stuck on python3 now. Once you get use-to then you can code in python2.7 also.)
Open a terminal, go the folder contains your code. If your source code is in hello.py then type python3 hello.py on terminal. It will execute and print the output on terminal.
The suggestions given by both #radj and #C. Dautermann are excellent.
Like others here, I will be assuming that you are on Windows.
Before jumping into LiClipse and PyDev, I highly recommend making sure that Python and packages (such as pip) are functioning on their own first. Command line is a great tool for this.
Windows Command Line can be accessed in a variety of ways, one of which is to go to your start menu and search "cmd." Command Prompt should return. In the command prompt, run the following:
python
This should return the version of Python installed on your machine if it is configured properly. For example, you may see the following:
Python 3.10.1 (...)[...] on win32
If this does not appear, I recommend uninstalling Python and reinstalling. In the installer, you will want to check the "Add Python ... to PATH" option. This will configure your environment variables on your machine. If you plan on running multiple versions of Python down the road, don't worry; you can use batch files to set the PATH variable to another version.
Once you have Python working, your command prompt will lead with the following:
>>>
Notice that there is no longer a file path followed by >>. This is because you are now in the Python interpreter. Congratulations!
To exit the Python interpreter, enter Ctrl+Z. It should appear as the following:
^Z
After we know Python works, we will check to see that pip works. Ensure you have pip installed by entering the following:
python -m pip --version
You should then be able to see the pip version. For example:
pip 22.0.3 from C:\...
If pip is not working, you can consult this documentation on pip to make sure pip gets installed properly.
Once pip is working, again, congratulations! You've gotten over some of the biggest hurdles. At this point, you can open up any text editor, type in:
print('Hello World!')
save the file with the extension .py, then run the script through command prompt. To run a script through the command line, you have to cd to the file location, then run the script with python, like so:
cd filepath
python filename.py
Where filepath is the path to the Python file and filename is the name of the file. For example:
cd C:\Users\name\Documents\PythonPractice
python helloworld.py
Usually, command line is all that is needed when starting out with Python outside of a text editor. Notepad comes standard on Windows computers, but there are plenty of other editors out there. Sublime text and Notepad++ are some of my favorites, personally.
Now, if you're able to run everything prior, the good news is that your Python and pip are both working, and you have everything you need to get started learning Python. If Python and/or pip are not functioning, there's thankfully a huge body of troubleshooting tips out there.
Unfortunately, from what I get of your initial post, you might be struggling with configuring LiClipse. I personally do not use LiClipse, nor do I use PyDev, so my help at this point may be limited. You may want to uninstall and reinstall after confirming your Python and pip work as a first step. After that, perhaps check that you are following the practices outlined in the LiClipse manual. Worst case scenario, you can try a different version of Python (I believe it has some Python3 incompatibilities), try running PyDev independent of LiClipse, or look at a different tool. If you believe the problem lies with file locations/existence, I would look at radj's post or play around in File Explorer to see what is going on for yourself.
Again, to get familiar with Python, you don't even need these extra tools. All you need is a text editor and the command line to get started.
Some other tools to help you get started:
PyPI
A venv virtual environment tutorial
PyDev
A comparison of LiClipse alternatives in case you continue to struggle
Hope this helps. Happy Coding!
The go clean -i command that is ran inside some project deletes an executable file of that particular project that was previously installed by go install command. How to delete everything installed by the go install commands that were ran from several different projects? Is there some single go command that can do that?
TL;DR
Delete the binary like any other file.
The "install" term means place (something) in a new position ready for use.
Therefore, Go builds a single-file binary and places it in another directory ($GOPATH/bin). It is useful when you add the Go binary directory into the environment variable to call the program.
There's no auxiliary flag such as go clean -bincache to remove all binaries installed by Go 1.16.4.
However, at the current version of GoLang (1.16.4), the right way to remove (or "uninstall" as you said) any installed binary is solely to delete it, like any other file despite you feel it sounds awkward.
I realize this is kind of a silly question, but I'm deeply curious about how I accomplish the following.
I created a shell script for my cohort at school which builds out large project templates. I've successfully published the package to npm, but after downloading, I can't get the script to run. I'd like for users to simply download the package and run something like $ npm project-template start(as an example) to trigger the script.
Is this possible?
If anyone has advice, suggestions, pointers, I'd really appreciate it. Thanks in advance!
Its always after I ask the internet for answers that I find the answers on my own.
Add the program to the binaries object
Basically, what I needed to do was to add the command I wanted to run to the bin section of the package.json:
"bin": {
"nameOfCommand": "path/to/script.sh"
}
The left side, nameOfCommand, is the name of the command that is used in your terminal
$ nameOfCommand args --options
The right side is the path to your CLI program, in this case, a bash/shell script.
The information can be found here in this article by NPM.
If I had a compiled Golang program that I wanted to install such that I could run it with a bash command from anywhere on my computer, how would I do that? For example, in nodejs
npm install -g express
Installs express such that I can run the command
express myapp
and express will generate a file directory for a node application called "myapp" in whatever my current directory is. Is there an equivalent command for go? I believe now with the "go install" command you have to be in the directory that contains the executable in order to run it
Thanks in advance!
Update: If you're using Go 1.16, this answer still works, but go install has changed and is now the recommended method for installing executable packages. See Karim's answer for an explanation: https://stackoverflow.com/a/68559728/10490740
Using Go >= 1.11, if your current directory is within a module-based project, or you've set GO111MODULE=on in your environment, go get will not install packages "globally". It will add them to your project's go.mod file instead.
As of Go 1.11.1, setting GO111MODULE=off works to circumvent this behavior:
GO111MODULE=off go get github.com/usr/repo
Basically, by disabling the module feature for this single command, it will install to GOPATH as expected.
Projects not using modules can still go get normally to install binaries to $GOPATH/bin.
There's a lengthy conversation and multiple issues logged about this change in behavior branching from here: golang/go - cmd/go: go get should not add a dependency to go.mod #27643.
Starting with Go >= 1.16 the recommended way to install an executable is to use
go install package#version
For example, go install github.com/fatih/gomodifytags#latest.
Executables (main packages) are installed to the directory named by the GOBIN environment variable, which defaults to $GOPATH/bin or $HOME/go/bin if the GOPATH environment variable is not set. You need to add this directory to your PATH variable to run executables globally. In my case, I've added this line to my ~/.zshrc file. (if you are using bash, add it to the ~/.bash_profile file):
export PATH="$HOME/go/bin:$PATH"
Go team published a blog post about this change, here's the explanation quote:
We used to recommend go get -u program to install an executable, but this use caused too much confusion with the meaning of go get for adding or changing module version requirements in go.mod.
Refer to go install documentation for more details
As far as I know, there is no direct equivalent to npm install -g. The closest equivalent would not be go install, but go get. From the help page (go help get):
usage: go get [-d] [-f] [-fix] [-insecure] [-t] [-u] [build flags] [packages]
Get downloads and installs the packages named by the import paths,
along with their dependencies.
By default, go get installs binaries to $GOPATH/bin, so the easiest way to make those binaries callable from everywhere is to add that directory to your $PATH.
For this, put the following line into your .bashrc (or .zshrc, depending on which shell you're using):
export PATH="$PATH:$GOPATH/bin"
Alternatively, you could also copy or link the executables to /usr/local/bin:
ln -s $GOPATH/bin/some-binary /usr/local/bin/some-binary
Short solution for Linux users:
Use the go get command as usual
Add the following lines to .bashrc:
# This is the default GOPATH, you should confirm with the 'go env' command
export GOPATH=$HOME/go
export PATH=$PATH:$GOROOT/bin:$GOPATH/bin
Restart terminal or source it. Installed binaries will be available globally.
For Go v1.8+
go install package_name#latest
Caveat: this answer is outdated following the 2020 deprecation of go get. The solution presented here won't work with newer Go runtime installs.
The closest analogue of this in Go would be go get. By default, it will fetch a Go package from a supplied repository URL, and requires a $GOPATH variable to be set in your shell so that Go knows where to store the packages (and subsequently where to find them when compiling code depending on go get-ted packages).
Example syntax:
$ go get github.com/user/repo
The behaviour supplied by npm's -g flag is default, and packages installed using go get are normally available globally.
See go get --help for more information about the command.
As mentioned by #helmbert, adding your $GOPATH to your $PATH is useful if you're installing standalone packages.
if you are using zsh :
first: install your package using :
go install package#version
then , you edit your .zshrc file
nano ~/.zshrc
Add this line to the end of .zshrc file :
export PATH="$HOME/go/bin:$PATH"
last but not least :
source ~/.zshrc
then open a new terminal and execute your command :)
TL;DR at the bottom. I'm going to walk you through how I came to this conclusion, and why the more obvious solutions don't work.
Upon seeing this question, I thought "If I could set root's GOPATH=/usr, it would install things in /usr/bin/ and /usr/src!"
So I tried the obvious thing:
Add GOPATH=/usr to root's .bashrc.
And it worked!
Sort of.
Not really.
Turns out, sudo doesn't execute root's .bashrc. For "security" or something like that.
Do env_set or something in /etc/sudoers
Turns out, /etc/sudoers can only remove environment variables. There's no env_set directive.
(As far as I can find)
Dig through man sudoers.
Where does sudo get it's default set of environment variables from?
Well, the first one in the list is /etc/environment, so that's the one I used.
sudo echo "GOPATH=/usr" >> /etc/environment
sudo go get <repo>
Binaries will be put in /usr/bin, and sources will be put in /usr/src.
Running go as non-root will use GOPATH the "normal" way.
If you don't have go installed, you may use the gobinaries. it builds an on-demand binary of the project from github repo.
The command to install the go package would be:
curl -sf https://gobinaries.com/rakyll/hey | sh
I install cygwin frequently enough that it would be handy to have the process automated. Specifically, I want to be able to specify ahead of time the packages that I want to install, so that I don't have to remember them at install-time. Is there any way to do this?
Yes, you can. Assuming you haven't installed Cygwin yet, bash isn't available, so you have to use a CMD script. Here's an example:
setup-x86.exe ^
--quiet-mode ^
--packages ^
aria2,^
atool,^
autoconf,^
...
xmlstarlet,^
zip
and add other packages to the list. The caret (^) character at the end of every line is the line continuation character in CMD scripts. The list of package names is comma-delimited, which is what the --packages option expects, although that's not documented.
You can run setup-x86.exe --help, or see the Cygwin FAQ, to read about the available command line options for setup.
If you name this script, say, setup.bat or setup.cmd, and put it in the same directory as setup-x86.exe, then you can run it to get a one-click install of Cygwin with all of the packages you want.
Note also that you'll have to specify the --site and --root options for a fresh install, or it will kick out of "quiet mode" and prompt the user anyway.
apt-cyg is similar to what I was looking for, although it requires a pre-existing cygwin install with a few non-default packages.
I don't know if you can script it, but I found a 'how-to' on making a custom package directory and the installer to go with it. This way, you can have all the packages you need and have the installer pre-selected.
You can find that article here.