Total newb here. I'm trying to get a simple ruby program to run in the terminal on my MacBook Pro. I used Atom text editor to write the following:
class Sample
def hello
puts "Hello, World!"
end
end
s = Sample.new
s.hello
I saved the file as my_program.rb to a folder on my desktop. I go to the terminal to run the program. I type
ruby my_program.rb
and it returns
ruby: No such file or directory -- my_program.rb (LoadError)
I can use the irb and run a single line of ruby using
ruby -e 'puts "hello world"'
But can't get it to find the .rb file.
I appreciate any help y'all can offer! Thanks!
ruby ~/Desktop/my_program.rb
Ruby might be clever, but is has no mind-reading builtin. You need to tell it, where your file is. This is, of course, not Ruby-specific, but applies to all commands - they can't guess, where in your file system you have stored a file.
An alternative would be to place ~/Desktop in your PATH and use
ruby -S my_program.rb
Ruby will then execute the first program with this name which it finds in $PATH. Whether it is wise to place the Desktop directory into the PATH is a different issue....
Related
Good afternoon! I have a problem with Ruby. I downloaded this program from the official site https://www.ruby-lang.org/en/downloads/ on Fedora without any problems (using the command via the terminal). However, I cannot use the 'irb' command in the terminal to run Ruby on Linux as described here https://www.ruby-lang.org/en/documentation/quickstart/. Therefore, I cannot learn the Ruby programming language.Command 'irb' not found
I tried my best to run Ruby in other ways. One of them, as is customary in Fedora, is to write the name of the program in the terminal. But it opens a folder in which, I assume, Ruby is located (I can't find the folder itself either in Files or via the 'cd' command in the terminal). I kind of can open this folder in the terminal, but I can't find it in Files.
Oh, by the way, the 'irb' command doesn't work there. Only some real command for a program like this one will work: irb(main):001:0> "Hello World" (from https://www.ruby-lang.org/en/documentation/quickstart/). The program is and is not at the same time
Move on. I made a text document, wrote irb(main):001:0> "Hello World" in it (as written in "Ruby in Twenty Minutes"), and saved the file as hello.rb . Opened the hello.rb file path through the terminal and wrote 'ruby hello.rb' (without quotes, of course). Result: syntax error. hello.rb file Tried to open hello.rb via ruby in terminal
Oh yeah, I almost forgot: when I tried to open hello.rb in Files through another application, there was no Ruby script in the list (ruby or irb or at least something through which one could open a .rb file). No program for .rb format
I hope I have explained the problem in sufficient detail and clearly. And I hope for your help and understanding! In any case, good mood to you!
On Fedora & CentOS, the Ruby installation is split into many smaller packages. If you want to run irb, you'll also have to install the ruby-irb package using dnf install ruby-irb.
How can I deploy a simple ruby script via homebrew?
Here's what I tried
Wrote formula in a GitHub repo named homebrew-foo
# file https://github.com/foo/homebrew-foo/blob/master/foo.rb
class Foo < Formula
desc "A command line tool"
url "https://github.com/foo/foo/archive/master.zip"
version "5.0.1"
def install
bin.install "foo"
lib.install Dir["lib/*"]
end
end
The other repository contains the ruby script. These are the files
./foo
./lib/libfile1.rb
here's what the script does
#!/usr/bin/env ruby
require './lib/libfile1.rb'
puts "came here"
The problem is that the require fails.
$ brew install foo/foo/foo
$ foo
results in this error
/Users/user1/.rbenv/versions/2.4.1/lib/ruby/2.4.0/rubygems/core_ext/kernel_require.rb:55:in
require': cannot load such file -- ./lib/libfile1.rb (LoadError)
from
/Users/user1/.rbenv/versions/2.4.1/lib/ruby/2.4.0/rubygems/core_ext/kernel_require.rb:55:in
require' from /usr/local/bin/foo
$ which foo
/usr/local/bin/foo
I suspect it's because the .rb file is not there at /usr/local/bin/foo/lib/libfile1.rb
Any ideas whats the proper way to do this?
There are two issues with your script:
The first one is you try to require some file relatively to the current directory; i.e. the one from which the script is run, not the one it’s located in. That issue can be fixed by using Ruby’s require_relative:
#!/usr/bin/env ruby
require_relative './lib/libfile1.rb'
puts "came here"
The second issue is the script assumes the lib/ directory is located in its directory; which it’s not because your formula installs the script under <prefix>/bin/ and the library files under <prefix>/lib/. Homebrew has a helper for that use-case called Pathname#write_exec_script. It lets you install everything you need under one single directory, then create an executable under bin/ that calls your script.
Your formula now looks like this:
class Foo < Formula
desc "A command line tool"
url "https://github.com/foo/foo/archive/master.zip"
version "5.0.1"
def install
libexec.install Dir["*"]
bin.write_exec_script (libexec/"foo")
end
end
It installs everything under libexec/ (lib/ is usually reserved for lib files), then add an executable under bin/ that calls your libexec/foo script.
I found the answer to my own question, actually it's a technique used by someone on the net, basically do something like this
#!/usr/bin/env ruby
DBMGR_HOME = File.expand_path('../..', __FILE__)
$LOAD_PATH.unshift(File.join(DBMGR_HOME, 'lib'))
require 'dbmgr'
And the recipe can be like this:
https://github.com/callahanrts/homebrew-dbmgr/blob/master/dbmgr.rb
I'm pretty inexperienced with terminal type stuff besides the most basic commands, I recently switched from Bash to ZSH with in oh-my-zsh. I'm trying to make an executable ruby script at usr/bin/test.rb. For what it's worth, I never tried this with bash so I have no idea if its zsh specific.
$~ test.rb
/usr/bin/test.rb: line 2: puts: command not found
$~ ruby test.rb
ruby: No such file or directory -- test.rb (LoadError)
and my .zshrc file:
export ZSH=$HOME/.oh-my-zsh
source $ZSH/oh-my-zsh.sh
export PATH="/Users/jason/.rvm/gems/ruby-2.0.0-p247/bin:/Users/jason/.rvm/gems/ruby- 2.0.0-p247#global/bin:/Users/jason/.rvm/rubies/ruby-2.0.0-p247/bin:/Users/jason/.rvm/bin:.git/safe/../../bin:.git/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/X11/bin:/Users/jason/.rvm/bin"
.
~ which ruby
/Users/jason/.rvm/rubies/ruby-2.0.0-p247/bin/ruby
test.rb
#!/usr/bin/env ruby
puts 'test!'
$~ test.rb
/usr/bin/test.rb: line 2: puts: command not found
This is probably because your script is missing an essential line, often called a "pound-bang line" or, more simply, a "bang line", which tells the operating system what program to use to execute the rest of the file. Typically, for Ruby scripts, it looks like:
#!/usr/bin/ruby
or
#!/usr/bin/env ruby
and MUST be the first line in the file. When the OS opens the file, it looks for #! and, if it sees those, launches the executable at the path given, and passes the script to it. That's basic script execution on a *nix system, and applies to sh/Bash/Perl/Python/Ruby and any number of other executable applications on a *nix system.
ruby test.rb
ruby: No such file or directory -- test.rb (LoadError)
I suspect the second failed because you weren't in the /usr/bin/ directory when you executed that command. Ruby tried to run the script but couldn't find it in the local/current directory.
I'm not trying to be cruel, but, as a programmer, you'll spend a huge amount of time at the command-line, especially so if you are programming in C/C++, Perl, Ruby, Python, or any non-IDE based language. You have to learn how the OS works otherwise disasters of varying sizes and shapes await you, so, in parallel to learning a language you need to learn how to use, and administer, your OS. You don't have to be a power-user or administrator, but you have to know enough to understand good instructions from ones that don't apply, or are just plain-wrong.
Well I was facing the same problem, I had ruby & rails installed but I couldn't run them on ZSH
The answer is so simple
Just Add the following lines to .zshrc
export PATH="$HOME/.rbenv/bin:$PATH"
eval "$(rbenv init -)"
Then run
source ~/.zshrc
After that to check if ruby & rails are found by ZSH run
ruby --version
rails --verison
I've set everything up that I need on my Mac (Ruby, Rails, Homebrew, Git, etc), and I've even written a small program. Now, how do I execute it in Terminal? I wrote the program in Redcar and saved it as a .rb, but I don't know how to execute it through Terminal. I want to run the program and see if it actually works. How do I do this?
Just call: ruby your_program.rb
or
start your program with #!/usr/bin/env ruby,
make your file executable by running chmod +x your_program.rb
and do ./your_program.rb some_param
Open your terminal and open folder where file is saved.
Ex /home/User1/program/test.rb
Open terminal
cd /home/User1/program
ruby test.rb
format or test.rb
class Test
def initialize
puts "I love India"
end
end
# initialize object
Test.new
output
I love India
Assuming ruby interpreter is in your PATH (it should be), you simply run
ruby your_file.rb
To call ruby file use : ruby your_program.rb
To execute your ruby file as script:
start your program with #!/usr/bin/env ruby
run that script using ./your_program.rb param
If you are not able to execute this script check permissions for file.
Just invoke ruby XXXXX.rb in terminal, if the interpreter is in your $PATH variable.
( this can hardly be a rails thing, until you have it running. )
For those not getting a solution for older answers, i simply put my file name as the very first line in my code.
like so
#ruby_file_name_here.rb
puts "hello world"
Although its too late to answer this question, but still for those guys who came here to see the solution of same problem just like me and didn't get a satisfactory answer on this page, The reason is that you don't have your file in the form of .rb extension. You most probably have it in simple text mode. Let me elaborate.
Binding up the whole solution on the page, here you go (assuming you filename is abc.rb or at least you created abc):
Type in terminal window:
cd ~/to/the/program/location
ruby abc.rb
and you are done
If the following error occurs
ruby: No such file or directory -- abc.rb (LoadError)
Then go to the directory in which you have the abc file, rename it as abc.rb
Close gedit and reopen the file abc.rb. Apply the same set of commands and success!
In case someone is trying to run a script in a RAILS environment,
rails provide a runner to execute scripts in rails context via
rails runner my_script.rb
More details here:
https://guides.rubyonrails.org/command_line.html#rails-runner
Open Terminal
cd to/the/program/location
ruby program.rb
or add #!/usr/bin/env ruby in the first of your program (script tell that this is executed using Ruby Interpreter)
Open Terminal
cd to/the/program/location
chmod 777 program.rb
./program.rb
You can run ruby code just passing -e option
ruby -e 'x = Time.now; puts x;'
Output will be:
2022-06-22 15:55:06 +0500
I'm trying to call a Ruby script from a bash script, but no luck.
#!/bin/bash
ruby -v
works just fine, so I know that it's not Ruby, but
#!/bin/bash
ruby bash_test.rb
does not. Here's the fun part:
john#starfire:~/Desktop$ bash ubuntu_cmds.sh
(LoadError)h file or directory -- bash_test.rb
john#starfire:~/Desktop$ ls *.rb
bash_test.rb
Both files are sitting on my desktop.
ruby bash_test.rb
works just fine, too.
I'm new to bash scripting, so I'm pretty sure that I'm just making a stupid error.
I'm running Ubuntu 10.10 with Ruby 1.8.7. Thanks in advance for any help or advice.
EDIT: Deleted the .sh and the .rb and started over, and made sure to chmod +x the .sh, and it worked on the first try. I have no idea why. Thanks for the help, though.
try
#!/bin/bash
ruby ~/Desktop/bash_test.rb
Do you have a carriage return in the bash script after the file name ?
EDITED
Double check how the filename is being passed to ruby in the bash script.
Error output should be as below if the file wasn't found
ruby: No such file or directory -- bash_test.rb (LoadError)
From what you are displaying as an error it appears that there is a carriage return that is being assumed by ruby as part of the filename so you are getting the following error output.
(LoadError)h file or directory -- bash_test.rb
You may have to do ruby ./bash_test.rb, as sometimes . isn't in your $PATH.