For my django projects, I wanted to write a simple replacement for manage.py shell to take advantage of bpython. Essentially all it does is run setup_environ(settings) and then import some common models (User, etc.)
in any case, everything works fine when I run bpython -i bshell.py (my script is named bshell.py). Then I thought I'd get clever and set the hashbang line to #!/usr/bin/env bpython -i to make it even simpler, and this worked on the OSX but is not working now in Ubuntu (10.10).
#!/usr/bin/env python -i also does not work, but #!/usr/bin/env bpython works (but obviously doesn't drop into the interactive prompt).
It's a small point, but over the course of my life it will save me hundreds of "bpython -i"s if I can just run my script as ./bshell.py (really I'm just curious). Any ideas why it's not working on Ubuntu?
I should note I'm in a virtualenv, and I already double checked that line endings are *nix style.
From wikipedia:
Another portability problem is the interpretation of the command arguments.
Some systems, including Linux, do not split up the arguments; for example,
when running the script with the first line like,
#!/usr/bin/env python -c
That is, python -c will be passed as one argument to /usr/bin/env,
rather than two arguments.
If it's no big deal, you're probably better off using the actual path to bpython instead of going through /usr/bin/env.
Related
I'm following along with Google's Python class, and the person in the videos always runs his scripts from the interactive session in command line using "./". Whenever I try it, I just get a syntax error. How can I use ./ to run scripts? I'm using Windows 10
To run a script from the command line you need to use the syntax
python3 script.py
Now on Unix systems, it's possible to add a shebang to the first line of the script as followings
#!/usr/bin/env python3
This then allows the shell syntax './name.py' to work. But windows doesn't have this mechanism. Instead, you need to create an 'association' between the .py extension and the python executable ('right click', 'open with'). Or just use the full syntax. Both require the python executable to be in your path, and generally on windows both python 2 and 3 will have the same executable name
I have a problem and hope someone can help me. I am currently trying to write a script for Termux or Termux:Task. My script currently looks like this:
#!/data/data/com.termux/files/usr/bin/bash
cd /./sdcard/www/public/
wp post list sleep 5
Every time I load the script I get the following error message:
/data/data/com.termux/files/usr/bin/wp: /usr/bin/env: bad interpreter: No such file or directory.
I've been looking for a solution to my problem for hours, unfortunately without success.
I am using an extension for Termux called "WordPress CLI". When I start termux and enter the commands individually, everything works. But as soon as I write the commands into a sh script and start it doesn't work anymore. :(
Can anyone help me?
Thanks a lot
This is simple error you can fix it by replacing !/data/data/com.termux/files/usr/bin/bash. With #!/data/data/com.termux/files/usr/bin/bash
Please tell if you get error again
Try with #!/usr/bin/env bash in the shebang line.
Termux-exec allows you to execute scripts with shebangs for traditional Unix file structures. So shebangs like #!/bin/sh and #!/usr/bin/env python should be able to run without termux-fix-shebang.
From https://wiki.termux.com/wiki/Termux-exec
According to doc:
Why do I keep getting a '/bin/sh bad interpreter' error?
This error is thrown due to access script interpreter at nonexistent
location.
Termux does not have common directories like /bin, /sbin, /usr/bin at
their standard place. There is an exception for certain devices where
/bin is a symbolic link to /system/bin, but that does not make a
difference.
Interpreters should be accessed at this directory only:
/data/data/com.termux/files/usr/bin
There are three ways to fix this:
Install termux-exec by using pkg install termux-exec. It won’t affect the current session, but after a restart should work without
any setup. Not needed if your Termux is up to date. If still not
working, try the next workaround.
Use command termux-fix-shebang to fix the shebang line of specified file.
Use termux-chroot from package proot to setup a chroot environment mimicking a normal Linux file system in Termux.
termux-fix-shebang my_script.py of second method work for me, which it modify the shebang(first line of my_script.py) from #!/usr/bin/env python to #!/data/data/com.termux/files/usr/bin/env python. Since /usr/bin/ is not exist in Android, that's why it throws the error /usr/bin/env: bad interpreter: No such file or directory. The other solution is run with python my_script.py, neither of my_script.py nor ./my_script.py.
In my test, termux-exec of the first method only work if I added correct shebang in main script(child OR child of child script no need) and ran command export LD_PRELOAD=/data/data/com.termux/files/usr/lib/libtermux-exec.so.
And for the issue of this question, error shows /usr/bin/env in the middle with /data/data/com.termux/files/usr/bin/wp even though the shebang of script #!/data/data/com.termux/files/usr/bin/bash looks ok, it means that wp command (located at /data/data/com.termux/files/usr/bin/wp) used inside the script contains shebang #!/usr/bin/env wp and should modify it to #!/data/data/com.termux/files/usr/bin/env wp too. termux-exec of first method should fix this specific case too(already has correct shebang in main script).
I have a python script that I want to execute from the terminal, but I don't want to use the command pythonscriptName.py, instead, I'd like to just type scriptName. Is that possible? If it is, how?
I had a look in here and here, but it doesn't work (probably because I'm on a different os).
I'm using python 2.7.9 on osx Yosemite (10.10.3).
Put this as the first line in your Python script:
#!/usr/bin/python
(or wherever your Python interpreter lives).
Then give the script the executable bit:
chmod +x scriptName.py
Now you should be able to execute it like ./scriptName.py. You can then put a symlink without the .py extension somewhere in your path.
Let's say I've got this one-line Python module called say_hello.py.
print 'Hello World'
How can I make the script executable from any location in my terminal? That is, having Hello World printed outside the Python interpreter anywhere on my system. I'm running on OS X Mavericks.
General *nix answer
First line of script should look something like:
#!/usr/bin/python
although the exact path may be different on your system. Then, make the script executable and put it somewhere in your PATH.
Add as the first line of your script:
#!/usr/bin/env python
or, for a python3 script:
#!/usr/bin/env python3
The shell (actually the kernel) will use the first Python/Python3 interpreter found in your $PATH.
In Fabric, when I try to use any alias' or functions from my .bash_profile file, they are not recognized. For instance my .bash_profile contains alias c='workon django-canada', so when I type c in iTerm or Terminal, workon django-canada is executed.
My fabfile.py contains
def test():
local('c')
But when I try fab test it throws this at me:
[localhost] local: c
/bin/sh: c: command not found
Fatal error: local() encountered an error (return code 127) while executing 'c'
Aborting.
Other Fabric functions work fine. Do I have to specify my bash profile somewhere in fabric?
EDIT - As it turns out, this was fixed in Fabric 1.4.4. From the changelog:
[Feature] #725: Updated local to allow override of which local shell is used. Thanks to Mustafa Khattab.
So the original question would be fixed like this:
def test():
local('c', shell='/bin/bash')
I've left my original answer below, which only relates to Fabric version < 1.4.4.
Because local doesn't use bash. You can see it clearly in your output
/bin/sh: c: command not found
See? It's using /bin/sh instead of /bin/bash. This is because Fabric's local command behaves a little differently internally than run. The local command is essentially a wrapper around the subprocess.Popen python class.
http://docs.python.org/library/subprocess.html#popen-constuctor
And here's your problem. Popen defaults to /bin/sh. It's possible to specify a different shell if you are calling the Popen constructor yourself, but you're using it through Fabric. And unfortunately for you, Fabric gives you no means to pass in a shell, like /bin/bash.
Sorry that doesn't offer you a solution, but it should answer your question.
EDIT
Here is the code in question, pulled directly from fabric's local function defined in the operations.py file:
p = subprocess.Popen(cmd_arg, shell=True, stdout=out_stream,
stderr=err_stream)
(stdout, stderr) = p.communicate()
As you can see, it does NOT pass in anything for the executable keyword. This causes it to use the default, which is /bin/sh. If it used bash, it'd look like this:
p = subprocess.Popen(cmd_arg, shell=True, stdout=out_stream,
stderr=err_stream, executable="/bin/bash")
(stdout, stderr) = p.communicate()
But it doesn't. Which is why they say the following in the documentation for local:
local is simply a convenience wrapper around the use of the builtin Python subprocess module with shell=True activated. If you need to do anything special, consider using the subprocess module directly.
One workaround is simply to wrap whatever command you have around a bash command:
#task
def do_something_local():
local("/bin/bash -l -c 'run my command'")
If you need to do a lot of these, consider creating a custom context manager.
It looks like you're trying to use virtualenvwrapper locally. You'll need to make your local command string look like this:
local("/bin/bash -l -c 'workon django-canada && python manage.py runserver'")
Here's an example by yours truly that does that for you in a context manager.