I am new to both linux and ruby. I am using Ubuntu and Ruby 1.9
When I do which ruby, I get /usr/bin/ruby
When I do ruby -v I get ruby 1.9.3p0 (2011-10-30 revision 33570)
[i686-linux]
When I try to kick off a simple script
#!/usr/bin/env
puts "Hello"
I get
./test.rb: line 1: #!/usr/bin/env: No such file or directory
./test.rb: line 4: puts: command not found
Why?
Thanks
Todd
--
Posted via http://www.ruby-forum.com/.
#!/usr/bin/env*ruby*
Hope that helps.
Sam
On 27/06/13 15:58, Todd Sterben wrote:
I am new to both linux and ruby. I am using Ubuntu and Ruby 1.9
When I do which ruby, I get /usr/bin/ruby
When I do ruby -v I get ruby 1.9.3p0 (2011-10-30 revision 33570)
[i686-linux]When I try to kick off a simple script
#!/usr/bin/env
puts "Hello"
I get
./test.rb: line 1: #!/usr/bin/env: No such file or directory
./test.rb: line 4: puts: command not foundWhy?
Thanks
Todd
Hello,
Shebang line should like "#! /usr/bin/env ruby" or "#! <path to your
ruby VM i.e /usr/bin/ruby>". This line tell shell which program to
run.
Regards,
On Thu, Jun 27, 2013 at 10:58 AM, Todd Sterben <lists@ruby-forum.com> wrote:
I am new to both linux and ruby. I am using Ubuntu and Ruby 1.9
When I do which ruby, I get /usr/bin/ruby
When I do ruby -v I get ruby 1.9.3p0 (2011-10-30 revision 33570)
[i686-linux]When I try to kick off a simple script
#!/usr/bin/env
puts "Hello"
I get
./test.rb: line 1: #!/usr/bin/env: No such file or directory
./test.rb: line 4: puts: command not foundWhy?
Thanks
Todd
--
Posted via http://www.ruby-forum.com/\.
--
Duong Quang Ha (Hà Quang Dương in Vietnamese)
blog.haqduong.com
Hi Todd!
!#/usr/bin/env ruby
it needs the token (i.e. program executable name) in front of the env
token. This makes your script portable.
You will want to make it exectutable which is done with the command chmod
like so:
% chmod +x /path/to/your-program
from there to exectute it you can do it one of three ways.
1. simply use dot slash in front of the program like: ./prog
2. type the whole path like: /home/todd/prog
3. set up a bin directory and set up your the PATH variable in your shells
rc file.
The last one is your homework =) With that you can just run your script
from anywhere and even incorporate it into other scripts and so on.
Congratulations and welcome to the wonderful world of UNIX and Ruby
Programming =)
Oh and one last word of advice. AUTOMATE EVERYTHING!
~Stu (15 years hacking shells networks and BSDs and GNUs )
On Wed, Jun 26, 2013 at 10:58 PM, Todd Sterben <lists@ruby-forum.com> wrote:
I am new to both linux and ruby. I am using Ubuntu and Ruby 1.9
When I do which ruby, I get /usr/bin/ruby
When I do ruby -v I get ruby 1.9.3p0 (2011-10-30 revision 33570)
[i686-linux]When I try to kick off a simple script
#!/usr/bin/env
puts "Hello"
I get
./test.rb: line 1: #!/usr/bin/env: No such file or directory
./test.rb: line 4: puts: command not foundWhy?
Thanks
Todd
--
Posted via http://www.ruby-forum.com/\.
Thanks for the responses. I should have been a bit more clear about my
UNIX skills. Not great, but I can move around and set permissions and
look at things like environment variables. So I had already set things
to execute. I still can't see what is up. Here is the code(again) and
files and symbolic links & path & permissions
Here is my beautiful code:
#!/usr/bin ruby
puts "Hello world!"
which produces these errors:
./test.rb: line 1: #!/usr/bin: No such file or directory
./test.rb: line 3: puts: command not found
/usr/bin is in PATH so it should not have a problem there:
/usr/lib/lightdm/lightdm:
/usr/local/sbin:
/usr/local/bin:/usr/sbin:
/usr/bin:/sbin:/bin:
/usr/games:
/usr/bin/ruby
ruby points, through symbolic links, to /usr/bin/ruby1.9.1
lrwxrwxrwx 1 root root 22 Jun 20 16:30 ruby -> /etc/alternatives/ruby
lrwxrwxrwx 1 root root 18 Jun 20 16:30 ruby -> /usr/bin/ruby1.9.1
-rwxr-xr-x 1 root root 5552 Mar 22 12:14 ruby1.9.1
And the code is here:
-rwxrwxrwx 1 john john 41 Jun 27 18:41 test.rb
I am going to /home/john to run the file ./test.rb
And everything is executable
--
Posted via http://www.ruby-forum.com/.
I added /env (and should have known better) and still get the same
errors
#!/usr/bin/env ruby
puts "Hello world!"
./test.rb: line 1: #!/usr/bin/env: No such file or directory
./test.rb: line 3: puts: command not found
--
Posted via http://www.ruby-forum.com/.
This works
$ /usr/bin/env ruby
puts "Hello world"
^D
$ ls -la /usr/bin/env Gives
-rwxr-xr-x 1 root root 22060 Nov 19 2012 /usr/bin/env
which env gives /usr/bin/env
which ruby gives /usr/bin/ruby
ruby -v gives ruby 1.9.3p0 (2011-10-30 revision 33570) [i686-linux]
--
Posted via http://www.ruby-forum.com/.
I changed my text editor and it works. Hidden characters?
--
Posted via http://www.ruby-forum.com/.
as others suggested you can do the following:
Link directly to your ruby executable:
#!/usr/bin/ruby
This line is called the shebang line, whenever your computer tries to read
a script, this line tells the computer what program to run this script
with. If you shebang to your ruby program directly, there is no issue. But
if you share the code, or install ruby to a different directory later on,
you have to change the line, some people might be using RVM, or have it
installed in #!/usr/local/bin/ruby instead. So we use the ENV program to
find the appropriate version of ruby in the PATH. #!/usr/bin/env ruby says
use the ruby that is returned by the env program. this way ENV returns the
ruby that is set for use in your systems path. This changes computer to
computer, so it is the most standard way of writing the shebang line to
make sure your code works on multiple machines. #!/usr/bin/env just dumps
your entire environment.
To see what I mean, type env in terminal and console. Then type env ruby
and see what happens.
Cheers,
Richard
On Wed, Jun 26, 2013 at 9:04 PM, Duong Quang Ha <quangduongha@gmail.com>wrote:
Hello,
Shebang line should like "#! /usr/bin/env ruby" or "#! <path to your
ruby VM i.e /usr/bin/ruby>". This line tell shell which program to
run.Regards,
On Thu, Jun 27, 2013 at 10:58 AM, Todd Sterben <lists@ruby-forum.com> > wrote:
> I am new to both linux and ruby. I am using Ubuntu and Ruby 1.9
>
> When I do which ruby, I get /usr/bin/ruby
> When I do ruby -v I get ruby 1.9.3p0 (2011-10-30 revision 33570)
> [i686-linux]
>
> When I try to kick off a simple script
>
> #!/usr/bin/env
>
> puts "Hello"
>
> I get
>
> ./test.rb: line 1: #!/usr/bin/env: No such file or directory
> ./test.rb: line 4: puts: command not found
>
>
> Why?
>
> Thanks
>
> Todd
>
> --
> Posted via http://www.ruby-forum.com/\.--
Duong Quang Ha (Hà Quang Dương in Vietnamese)
blog.haqduong.com
--
*Richard Wilson*
Proteous Trading Group
ph. - (604) 842 5318
Skype - r.crawfordwilson
email - r.crawfordwilson@gmail.com
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email is prohibited”.*
Well that's embarrassing. It's hash bang... I had reversed it while typing
to fast. My apologize.
Todd to know more about chmod read the man page:
% man chmod
It stands for change mode. Basically it's turning on the execute bit when
you use +x.
~Stu
On Thu, Jun 27, 2013 at 12:13 AM, Stu <stu@rubyprogrammer.net> wrote:
Hi Todd!
!#/usr/bin/env ruby
it needs the token (i.e. program executable name) in front of the env
token. This makes your script portable.You will want to make it exectutable which is done with the command chmod
like so:% chmod +x /path/to/your-program
from there to exectute it you can do it one of three ways.
1. simply use dot slash in front of the program like: ./prog
2. type the whole path like: /home/todd/prog
3. set up a bin directory and set up your the PATH variable in your shells
rc file.The last one is your homework =) With that you can just run your script
from anywhere and even incorporate it into other scripts and so on.Congratulations and welcome to the wonderful world of UNIX and Ruby
Programming =)
Oh and one last word of advice. AUTOMATE EVERYTHING!~Stu (15 years hacking shells networks and BSDs and GNUs )
On Wed, Jun 26, 2013 at 10:58 PM, Todd Sterben <lists@ruby-forum.com>wrote:
I am new to both linux and ruby. I am using Ubuntu and Ruby 1.9
When I do which ruby, I get /usr/bin/ruby
When I do ruby -v I get ruby 1.9.3p0 (2011-10-30 revision 33570)
[i686-linux]When I try to kick off a simple script
#!/usr/bin/env
puts "Hello"
I get
./test.rb: line 1: #!/usr/bin/env: No such file or directory
./test.rb: line 4: puts: command not foundWhy?
Thanks
Todd
--
Posted via http://www.ruby-forum.com/\.
#!/usr/bin/env ruby
*or*
#!/usr/bin/ruby
Prefer the former over the latter =]
Sam
On 28/06/13 13:55, Todd Sterben wrote:
Thanks for the responses. I should have been a bit more clear about my
UNIX skills. Not great, but I can move around and set permissions and
look at things like environment variables. So I had already set things
to execute. I still can't see what is up. Here is the code(again) and
files and symbolic links & path & permissionsHere is my beautiful code:
#!/usr/bin ruby
puts "Hello world!"
which produces these errors:
./test.rb: line 1: #!/usr/bin: No such file or directory
./test.rb: line 3: puts: command not found/usr/bin is in PATH so it should not have a problem there:
/usr/lib/lightdm/lightdm:
/usr/local/sbin:
/usr/local/bin:/usr/sbin:
/usr/bin:/sbin:/bin:
/usr/games:
/usr/bin/rubyruby points, through symbolic links, to /usr/bin/ruby1.9.1
lrwxrwxrwx 1 root root 22 Jun 20 16:30 ruby -> /etc/alternatives/ruby
lrwxrwxrwx 1 root root 18 Jun 20 16:30 ruby -> /usr/bin/ruby1.9.1
-rwxr-xr-x 1 root root 5552 Mar 22 12:14 ruby1.9.1
And the code is here:
-rwxrwxrwx 1 john john 41 Jun 27 18:41 test.rb
I am going to /home/john to run the file ./test.rb
And everything is executable
Thanks for the responses. I should have been a bit more clear about my
UNIX skills. Not great, but I can move around and set permissions and
look at things like environment variables. So I had already set things
to execute. I still can't see what is up. Here is the code(again) and
files and symbolic links & path & permissionsHere is my beautiful code:
#!/usr/bin ruby
Change that to: #!/usr/bin/env ruby
puts "Hello world!"
which produces these errors:
./test.rb: line 1: #!/usr/bin: No such file or directory
./test.rb: line 3: puts: command not found/usr/bin is in PATH so it should not have a problem there:
/usr/lib/lightdm/lightdm:
/usr/local/sbin:
/usr/local/bin:/usr/sbin:
/usr/bin:/sbin:/bin:
/usr/games:
/usr/bin/rubyruby points, through symbolic links, to /usr/bin/ruby1.9.1
lrwxrwxrwx 1 root root 22 Jun 20 16:30 ruby -> /etc/alternatives/ruby
lrwxrwxrwx 1 root root 18 Jun 20 16:30 ruby -> /usr/bin/ruby1.9.1
-rwxr-xr-x 1 root root 5552 Mar 22 12:14 ruby1.9.1
And the code is here:
-rwxrwxrwx 1 john john 41 Jun 27 18:41 test.rb
I am going to /home/john to run the file ./test.rb
And everything is executable
--
Posted via http://www.ruby-forum.com/\.
Everything looks fine except for the one change I mentioned above.
With the shebang line, you are telling bash to execute "/usr/bin/env",
passing it one parameter, "ruby". The "env" program will then launch the
appropriate "ruby" executable.
The reason for this is that "shebang" line must specify a complete path to
an executable (either an absolute path or one relative to the current
working directory; relative paths are problematic though so everyone uses
absolute paths). Since the "ruby" executable may be installed in a
different location on different systems, the convention is to instead run
ruby via the "env" command for which it is safe to assume it'll be
available in the /usr/bin directory.
The "env" command lets you run other commands in a modified environment.
However, in this case, it's just being used for the fact that it'll look up
whatever command you tell it to run using the PATH environment variable.
So, as long as an executable (or a symlink to one) is in one of the
directories in your PATH (which is the case on your system) then "env" can
run it.
You can try it manually inside your shell (the "^D" mean, type CTRL-D; you
won't actually see the "^D" characters):
$ /usr/bin/env ruby
puts "Hi"
^D
Hi
$
The above runs ruby which reads it's input (ruby code) from the terminal.
The CTRL-D tells ruby it's reached the end of the file so it will exit, at
which point it will run whatever ruby code you entered (outputting "Hi" to
the terminal).
On Thu, Jun 27, 2013 at 7:55 PM, Todd Sterben <lists@ruby-forum.com> wrote:
--
Kendall Gifford
zettabyte@gmail.com
Try this in your shell:
which env
If you get nothing, try this:
which ruby
If you get nothing, you are stuck (your $PATH is probably broken).
echo $PATH
Sam
On 28/06/13 14:39, Todd Sterben wrote:
I added /env (and should have known better) and still get the same
errors#!/usr/bin/env ruby
puts "Hello world!"
./test.rb: line 1: #!/usr/bin/env: No such file or directory
./test.rb: line 3: puts: command not found
What's the output of:
$ ls -la /usr/bin/env
What happens if you try the by-hand experiment I mentioned in my last
message:
$ /usr/bin/env ruby
puts "Hello world"
^D
(where the ^D means type CTRL-D)
On Thu, Jun 27, 2013 at 8:39 PM, Todd Sterben <lists@ruby-forum.com> wrote:
I added /env (and should have known better) and still get the same
errors#!/usr/bin/env ruby
puts "Hello world!"
./test.rb: line 1: #!/usr/bin/env: No such file or directory
./test.rb: line 3: puts: command not found
--
Kendall Gifford
zettabyte@gmail.com
What happens when you type ruby in front of it like:
% ruby test.rb
On Fri, Jun 28, 2013 at 12:12 AM, Todd Sterben <lists@ruby-forum.com> wrote:
This works
$ /usr/bin/env ruby
puts "Hello world"
^D$ ls -la /usr/bin/env Gives
-rwxr-xr-x 1 root root 22060 Nov 19 2012 /usr/bin/env
which env gives /usr/bin/env
which ruby gives /usr/bin/ruby
ruby -v gives ruby 1.9.3p0 (2011-10-30 revision 33570) [i686-linux]--
Posted via http://www.ruby-forum.com/\.
It *might be* the line endings.
If I have "DOS" style line endings in a file then on Linux I see:
vagrant@precise64:/vagrant$ cat try.rb
#!/usr/bin/env ruby
puts "Hello"
vagrant@precise64:/vagrant$ ls -l try.rb
-rwxrwxr-x 1 vagrant vagrant 37 Jun 29 23:38 try.rb
vagrant@precise64:/vagrant$ ./try.rb
: No such file or directory
On my Mac trying the same thing I get a more obvious clue:
ratdog:vagrant_book_example mike$ ./try.rb
env: ruby\r: No such file or directory
Which tells me there is a \r at the end of the #! line. I often use the file command to check, again on Linux:
vagrant@precise64:/vagrant$ file try.rb
try.rb: a ruby\015 script, ASCII text executable, with CRLF line terminators
The CRLF is one give-away.
Hope this helps,
Mike
On 2013-06-29, at 7:15 PM, Todd Sterben <lists@ruby-forum.com> wrote:
I changed my text editor and it works. Hidden characters?
--
Posted via http://www.ruby-forum.com/\.
--
Mike Stok <mike@stok.ca>
http://www.stok.ca/~mike/
The "`Stok' disclaimers" apply.