Putting links to scripts in my cygwin bin - shell

I have made a few python scripts, but is there an easier way to run them? I am using cygwin.
python "C:\Users\Desk\Dropbox\scripts\wsort.py" > data11414_unsorted.txt < data11414_sorted.txt
I want something like this (not typing the path name or "python"):
wsort > data11414_unsorted.txt < data11414_sorted.txt
where wsort is a link to my real wsort.py

Add a
Shebang
to the script
#!/bin/python
then invoke like this
wsort.py > data11414_unsorted.txt < data11414_sorted.txt

First, your question has a Windows-style path (backslashes, beginning with C:) rather than a Cygwin path (/cygdrive/c/Users/Desk/Dropbox/scripts/wsort.py). That implies you're not actually using Cygwin, or if you are, you're ignoring a bunch of warnings.
The below assumes you're using Cygwin Bash (which should be what you get if you start Cygwin Terminal from the Start Menu) and Cygwin Python (which you've installed using Cygwin's setup.exe, not a Windows Python installer). If your not, you're making life more difficult for yourself than you need to.
That out the way, there's a bunch of steps you need to take:
First, make the script executable. Use the chmod command for that, from a Cygwin Bash shell:
chmod +x /cygdrive/c/Users/Desk/Dropbox/scripts/wsort.py
Second, tell the system how to execute it. Add the following line to the top of the script:
#!/bin/python
(That's a "shebang". Python sees it as a comment, so doesn't do anything with it, but Cygwin and other Linux-like systems will use that line to see which program to run the script with. In this case, Python.)
Third, make sure your line endings are correct. Cygwin expects Linux line endings and will fail without them. This may not be a problem, but there's no harm in doing this. Run the following command:
dos2unix /cygdrive/c/Users/Desk/Dropbox/scripts/wsort.py
At this point, you'll be able to call the script by specifying the full path to it in Cygwin. You can't yet run it without specifying where the script is explicitly.
The fourth step is making sure the script is "in your path", ie in one of the folders where Cygwin looks for scripts to run. There are lots of ways to do this, but the most sensible is probably to just add your scripts directory to your path. The following command will add your scripts directory to your path whenever you start a new Cygwin session:
echo 'PATH="/cygdrive/c/Users/Desk/Dropbox/scripts:$PATH"' >>~/.bashrc
You will need to restart your Cygwin terminal for that to take effect, however.
At that point, you'll be able to run the script in Cygwin just by typing wsort.py (and thus use it with redirections and so forth as in your question).
Finally, to be able to call it simply as wsort, there's a number of options. The obvious one is just renaming the file. More usefully (and without copying the file or doing anything liable to break with Dropbox syncing things), try creating an alias:
echo 'alias wsort=wsort.py' >>~/.bashrc
Again, you'll need to restart your Cygwin terminal for that to take effect.

Maybe use an alias ?
alias wsort = "Command_Used"

Related

call blat from shell script, w8

Trying to execute blat http://www.blat.net/ from a shell script. I set the environmental PATH variable, and i can call blat from any location with the command prompt. Sending email from the command line works fine. But I'm not able to call it from within a shell script.
The (simplified) script
#!/bin/bash
blat
I get:
$ sh script.sh
script.sh: line 2: blat: command not found
I also tried by specifying the absolute path C:/Windows/System32/blat but that didn't work either.
There are many ways to solve this. If you will only run blat from Bash, you can
just put it in /usr/local/bin AKA C:\cygwin64\usr\local\bin.
If you need to run it from Bash and cmd/PowerShell, Windows "out of the box" has
pretty poor support for that. With Linux/Bash your PATH will usually look
something like this:
/usr/local/bin:/usr/bin
This is great because you have a system space, and a user space for programs.
However Windows looks like this:
C:\Windows\System32;C:\Windows
As you can see by default the PATH only has system space. This is bad because it
encourages people to do dumb things like put user programs alongside protected
operating system files. What Windows needs is the equivalent of
/usr/local/bin, a folder on the PATH, ahead of everything where people can
dump command line programs. Until that happens you just have to add your own:
Move blat.exe to C:\Users\<user>\Documents
Add that to PATH:
SETX PATH "%PATH%;C:\Users\<user>\Documents" /M
When you add it to Windows PATH, it automatically gets added to Bash PATH, so
the program should be available to all shells.

What is the Bash file extension?

I have written a bash script in a text editor, what extension do I save my script as so it can run as a bash script? I've created a script that should in theory start an ssh server. I am wondering how to make the script execute once I click on it. I am running OS X 10.9.5.
Disagreeing with the other answers, there's a common convention to use a .sh extension for shell scripts -- but it's not a useful convention. It's better not to use an extension at all. The advantage of being able tell that foo.sh is a shell script because of its name is minimal, and you pay for it with a loss of flexibility.
To make a bash script executable, it needs to have a shebang line at the top:
#!/bin/bash
and use the chmod +x command so that the system recognizes it as an executable file. It then needs to be installed in one of the directories listed in your $PATH. If the script is called foo, you can then execute it from a shell prompt by typing foo. Or if it's in the current directory (common for temporary scripts), you can type ./foo.
Neither the shell nor the operating system pays any attention to the extension part of the file name. It's just part of the name. And by not giving it a special extension, you ensure that anyone (either a user or another script) that uses it doesn't have to care how it was implemented, whether it's a shell script (sh, bash, csh, or whatever), a Perl, Python, or Awk script, or a binary executable. The system is specifically designed so that either an interpreted script or a binary executable can be invoked without knowing or caring how it's implemented.
UNIX-like systems started out with a purely textual command-line interface. GUIs like KDE and Gnome were added later. In a GUI desktop system, you can typically run a program (again, whether it's a script or a binary executable) by, for example, double-clicking on an icon that refers to it. Typically this discards any output the program might print and doesn't let you pass command-line arguments; it's much less flexible than running it from a shell prompt. But for some programs (mostly GUI clients) it can be more convenient.
Shell scripting is best learned from the command line, not from a GUI.
(Some tools do pay attention to file extensions. For example, compilers typically use the extension to determine the language the code is written in: .c for C, .cpp for c++, etc. This convention doesn't apply to executable files.)
Keep in mind that UNIX (and UNIX-like systems) are not Windows. MS Windows generally uses a file's extension to determine how to open/execute it. Binary executables need to have a .exe extension. If you have a UNIX-like shell installed under Windows, you can configure Windows to recognize a .sh extension as a shell script, and use the shell to open it; Windows doesn't have the #! convention.
You don't need any extension (or you could choose an arbitrary one, but .sh is a useful convention).
You should start your script with #!/bin/bash (that first line is understood by execve(2) syscall), and you should make your file executable by chmod u+x. so if your script is in some file $HOME/somedir/somescriptname.sh you need to type once
chmod u+x $HOME/somedir/somescriptname.sh
in a terminal. See chmod(1) for the command and chmod(2) for the syscall.
Unless you are typing the whole file path, you should put that file in some directory mentioned in your PATH (see environ(7) & execvp(3)), which you might set permanently in your ~/.bashrc if your login shell is bash)
BTW, you could write your script in some other language, e.g. in Python by starting it with #!/usr/bin/python, or in Ocaml by starting it with #!/usr/bin/ocaml...
Executing your script by double-clicking (on what? you did not say!) is a desktop environment issue and could be desktop specific (might be different with
Kde, Mate, Gnome, .... or IceWM or RatPoison). Perhaps reading EWMH spec might help you getting a better picture.
Perhaps making your script executable with chmod might make it clickable on your desktop (apparently, Quartz on MacOSX). But then you probably should make it give some visual feedback.
And several computers don't have any desktop, including your own when you access it remotely with ssh.
I don't believe it is a good idea to run your shell script by clicking. You probably want to be able to give arguments to your shell script (and how would you do that by clicking?), and you should care about its output. If you are able to write a shell script, you are able to use an interactive shell in a terminal. That it the best and most natural way to use a script. Good interactive shells (e.g. zsh or fish or perhaps a recent bash) have delicious and configurable autocompletion facilities and you won't have to type a lot (learn to use the tab key of your keyboard). Also, scripts and programs are often parts of composite commands (pipelines, etc...).
PS. I'm using Unix since 1986, and Linux since 1993. I never started my own programs or scripts by clicking. Why should I?
just .sh.
Run the script like this:
./script.sh
EDIT: Like anubhava said, the extension doesn't really matter. But for organisational reasons, it is still recommended to use extensions.
I know this is quite old now but I feel like this adds to what the question was asking for.
If your on a mac and you want to be able to run a script by double clicking it you need to use the .command extension. Also same as before make file executable with chmod -x.
As was noted before, this isn't really that useful tbh.
TL;DR -- If the user (not necessarily the developer) of the script is using a GUI interface, it depends on what file browser they are using. MacOS's Finder will require the .sh extension in order to execute the script. Gnome Nautilus, however, recognizes properly shebanged scripts with or without the .sh extension.
I know it's already been said multiple times the reasons for and against using an extension on bash scripts, but not as much why or why not to use extensions, but I have what I consider to be a good rule of thumb.
If you're the type who hops in and out of bash and using the terminal in general or are developing a tool for someone else who does not use the terminal, put a .sh extension on your bash scripts. That way, users of that script have the option of double-clicking on that file in a GUI file browser to run the script.
If you're the type who primarily does all or most of your work in the terminal, don't bother putting any extension on your bash scripts. They would serve no purpose in the terminal, assuming that you've already set up your ~/.bashrc file to visually differentiate scripts from directories.
Edit:
In the Gnome Nautilus file browser with 4 test files (each with permissions given for the file to be executed) with stupidly simple bash command to open a terminal window (gnome-terminal):
A file with NO extension with #!/bin/bash on the first line.
It worked by double-clicking on the file.
A file with a .sh extension with #!/bin/bash on the first line.
It worked by double-clicking on the file.
A file with NO extension with NO #!/bin/bash on the first line.
It worked by double-clicking on the file...technically, but the GUI gave no indication that it was a shell script. It said it was just a plain text file.
A file with a .sh extension with NO #!/bin/bash on the first line.
It worked by double-clicking on the file.
However, as Keith Thompson, in the comments of this answer, wisely pointed out, relying on the using the .sh extension instead of the bash shebang on the first line of the file (#!/bin/bash) it could cause problems.
Another however, I recall when I was previously using MacOS, that even properly shebanged (is that a word?) bash scripts without a .sh extension could not be run from the GUI on MacOS. I would love for someone to correct me on that in the comments though. If this is true, it would prove that there is a least one file browser out there where the .sh extension matters.

Run a bash script in cygwin using ./

I have a simple bash script that throw errors on a Windows machine in the Cygwin xterm terminal when I call it like so: ./myscript.bat. It runs fine when I call it like this: /cygdrive/c/cygwin/bin/bash.exe myscript.bat. I am thinking that my shell is not using bash by default. How can I set it to bash so that the next time I open the shell, I can execute my script using ./myscript.bat?
When you execute a file, Windows (or some component within Windows) decides how to execute it based on the extension part of the file name.
Cygwin inherits this functionality, letting you run Windows commands from within Cygwin. Cygwin also implements most of the usual UNIX functionality (running commands based on their content), but the combination of UNIX and Windows semantics can't always be perfectly clean.
The .bat suffix refers to a Windows batch file, so when you try to execute myscript.bat, the system treats it that way rather than as a bash script.
Change the file name from myscript.bat to myscript.bash or myscript.sh -- or just drop the extension altogether (since someone running your script shouldn't need to care how it's written).
There are several other filename extensions you should avoid (like .cmd), depending on how Windows is configured. A few quick experiments show that a .sh extension is safe, but really you don't need to use an extension at all for a shell script.
And, as R Sahu's answer says, you also need to make sure the script has execute permission if you haven't already done so:
mv myscript.bat myscript
chmod +x myscript
You'll probably need to change permissions of the file to make it an executable.
Try
chmod +x myscript.bat
./myscript.bat

Cygwin automatic script launch

Im trying to automatically run a script using Cygwin via CMD. I basically created a BAT file that goes to the directory and executes an .SH file. SH files are accosiated with Cygwin, and I tried something like "cygwin update.sh" in the command line. But all it really does is open Cygwin. I want Cygwin to automatically run the script file. Is there any easy way to do this, I've been trying to find but can't. Thank you!
You'll want to call the shell script with a particular shell, e.g. bash.
When having Cygwin open, call which bash to figure out where the binary is located. Cygwin also comes with tools that can convert paths between Cygwin and Win32 form, which is pretty helpful in cases like yours.
There is one other thing that may work, depending on your setup. There is an environment variable named PATHEXT which declares file extensions that are deemed "executable" by CMD. This can be used to your advantage, if Windows is configured so that the shell's "open" verb executes the correct shell for the file extension .sh (in your case).
Good luck.
From Cygwin Terminal, read man mintty. Try something like the following from a Windows Command Prompt:
c:\cygwin\bin\mintty --hold always --exec /cygdrive/c/path/to/bash/script.sh
I also found this!
http://rothmanshore.com/2011/01/26/kick-off-a-cygwin-script-from-a-windows-bat-file-with-a-different-working-directory/
I didn't quite understand it at first, but then it worked as I wanted it. Just if anyone knows, is there a way to make the script run without the CMD window open?? Thanks

Can I use cygwin to script a hudson build step?

I've tried executing the following:
#!C:\cygwin\bin\bash.exe
ls ${WORKSPACE}
But that doesn't find ls (even if it's on the windows path). Is there any way to set this up?
UPDATE: In other words, I want to be able to set up a build step that uses cygwin bash instead of windows cmd like this page shows you how to do with Python.
So put your cygwin's bin directory in your PATH.
In case you don't know how to do it (Control Panel -> System -> Advanced -> Environment Variables), see: http://support.microsoft.com/kb/310519
That shell-script has two errors: the hash-bang line should be "#!/bin/bash", and ${WORKSPACE} is not a shell-variable. Hudson has a bunch of variables of its own which are expanded in the commands you specify to be run (i.e. when you add commands in the web gui).
If you want to run Hudson build step on the Cygwin command line, you need to figure out what command Hudson runs and in which directory.
To give a more specific answer, you need to show us how your project is configured and what steps you want to run separately.
Provided cygwin's bin folder is in your path, the following works for me:
#!/bin/sh
ls ${WORKSPACE}
I find Hudson does not pick up environment variable changes unless you restart the server.
you might want to try to give a full path to ls
/cygdrive/c/cygwin/bin/ls
One other thing that seems to work is to use this:
#!C:\cygwin\bin\bash.exe
export PATH=$PATH:/usr/bin
ls
But it would be nice not to have to modify the path for every script.
Have you thought about power shell? as much as I like cygwin, it's always been a little flaky, powershell is a solid fully functional shell on windows, another option is Windows Services for UNIX it gives you korn shell or c shell not quite as nice as bash but it gets the job done
You will need to pass the --login (aka -l) option to bash so that it will source Cygwin's /etc/profile and set up the PATH variable correctly. This will cause the current directory to get changed to the default "home" but you can set the environment variable CHERE_INVOKING to 1 before running bash -l and it will stay in the current directory if you need to preserve that.

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