How To Run This Script More Easily - ruby

I have a Ruby script that I wrote that sorts some files in a jumble of directories based on it's file extension. It would be very difficult to sort it using a GUI, and its easier for me to just put the file in the topmost directory and let the sorter do the work.
Problem is, I'm a bit of a noob to unix scripting. What I want to be able to do is be able to run that sorter script from anywhere on my computer, without having to
cd Desktop/Whatever/Foo
ruby sorterscript.rb
just write sortfolders at the commandline and have the program be run.
I've tested the script many times, and it works fine, I just want a bit more convenience.
Bonus: If possible, and not too difficult, it would be even better if I could have the program run, say, every hour automatically.

As far as your first question goes, you need to do couple of things:
Add a shebang line to your script (make it the first line of the script):
#!/usr/bin/ruby (or whatever the path to the Ruby interpreter's executable is, I forget its exact location)
Make the script executable, either via the Finder's "Get Info" context menu, or via the command line, for example:
chmod 755 my_script.rb
Add the directory location of your script to the PATH environment variable to OS X's launchd.conf file, as described here. You need to add this line:
setenv PATH /path/to/my/script:$PATH (substitute the real path to your script)
As far as your bonus question goes, you can use cron to set up a recurring job. I never really do this, but here's Apple's cron man page to get you started.

Related

How do I give my shell script a simple word to make it run. For example "mkdir"

so I have a bash script right now which automates the git process for me. I have made the shell script accessible from everywhere. I want to give the script a command like "ctdir" instead of typing in "intilize_directory.sh" every time. Is there a way to make this possible?
There are (at least) three ways to do this:
First, if it's on your path, you can simply rename it to ctdir.
Second, you can create an alias for it in your startup scripts (like $HOME/.bashrc):
alias ctdir='initialize_directory.sh'
Third, you can create a function to do the work (again, defining it in your startup scripts):
ctdir() {
initialize_directory.sh
}
Just remember to make sure you load up your modified startup scripts after making the changes. New shells should pick the changes up but you may need to re-source it manually from an existing shell (or just exit and restart).
Agreed with #paxdiablo, the best way is to create an alias.
Following steps will work in Linux:
Naming the alias.
Type the following at the command line:
alias ctdir='initialize_directory.sh'
Edit bashsrc file.
This file is usually present at your home directory.
Add at the alias mentioned in step 1 at the end of the bashsrc file to make them permanent and reusable in every session.
vi ~/.bashsrc

Instead of giving command for batch mode, give .scm file path?

It is possible to supply batch commands directly with the -b flag, but if the commands become very long, this is no longer an option. Is there a way to give the path to an .scm script that was written to a file, without having to move the file into the scripts directory?
No as far as I know. What you give in the -b flag is a Scheme statement, which implies your function has already been loaded by the script executor process. You can of course add more directories that are searched for scripts using Edit>Preferences>Folders>Scripts.
If you write your script in Python the problem is a bit different since you can alter the Python path before loading the script code but the command line remains a bit long.

Shell script sh executable - edit to see script

Is there a way to see the original code of a executable sh script. (I am very new to Linux and trying to understand what things do and such.)
If you know how I need very clear step by step process so I can just type i the commands and run them.
Thanks for your help. Trying to learn (Windows man for 25 years here)
A shell script specifically can be seen in the original text form by simply printing the contents of the file:
cat disk-space.sh.x
Several caveats:
If you mean an executable rather than a script the situation is different. Scripts are read by an interpreter at runtime, which then executes it line by line. Executables may be either scripts or ELF binaries. The latter have been transformed from the original source code to a machine readable form which is very much harder to read for humans.
The extension of the file (.sh.x or .x) does not control whether the file contents are executed as a binary or script.
If the file really is a script it may have been obfuscated, meaning that the source code on your system has deliberately been changed to make the resulting file hard to read.

Changing directory for User in Ruby script

I'm quite familiar with Dir.chdir("/xyz")
Unfortunately, this changes the directory of the process, but not actually the directory of the user. I'll make the following example to illustrate my need.
$~/: ruby my_script.rb
CHANGING TO PATH FOR USER NOT SCRIPT
$/Projects/Important/Path: pwd
$/Projects/Important/Path
See? I need the script to change the user's path. Performing system/backticks/Dir.chdir all adjust the process path, and end with the user sitting where they started, instead of the path I want them.
From what I've read exec was the way to go, since it takes over the existing process... but to no avail.
You can't, but you can do something which might be good enough. You can invoke another shell from ruby:
Dir.chdir("/xyz")
system("bash")
Running this will create a new bash process, which will start in the /xyz directory. The downside is that changing this process will bring you back to the ruby script, and assuming it ends right away - back to the bash process that started the ruby script.
Another hack that might work is to use the prompt as a hackish hook that will be called after each command. In the ruby script, you can write the new directory's path somewhere that can be read from both bash and ruby(for example a file - but not an environment variable!). In the PROMPT_COMMAND function, you check that file and cd to what's written there. Just make sure you delete that file, so you don't get automatically cded there after every command you run.

Is it possible to override hashbang/shebang path behavior

I have a bunch of scripts (which can't be modified) written on Windows. Windows allows relative paths in its #! commands. We are trying to run these scripts on Unix but Bash only seems to respect absolute paths in its #! directives. I've looked around but haven't been able to locate an option in Bash or a program designed to replace and interpreter name. Is it possible to override that functionality -- perhaps even by using a different shell?
Typically you can just specify the binary to execute the script, which will cause the #! to be ignored. So, if you have a Python script that looks like:
#!..\bin\python2.6
# code would be here.
On Unix/Linux you can just say:
prompt$ python2.6 <scriptfile>
And it'll execute using the command line binary. I view the hashbang line as one which asks the operating system to use the binary specified on the line, but you can override it by not executing the script as a normal executable.
Worst case you could write some wrapper scripts that would explicitly tell the interpreter to execute the code in the script file for all the platforms that you'd be using.

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