How to run a bash script as a command? - bash

I have a bash script that I would like to run globally as a command. For that I moved the script to /usr/local/bin/somefile.sh.
Now I still have to call a command called somefile.sh. I would like to have an alias for this command (for example I would just like to call the script with the command sf).
How do I do that?

And to complement answer from #Kent :
alias sf='/usr/local/bin/somefile.sh' using alias
ln -s somefile.sh /usr/local/bin/sf using soft link
mv /usr/local/bin/somefile.sh /usr/local/bin/sf using renaming

There are different ways:
as you mentioned, use alias, man alias for details
create a soft link named sf to your real script
rename your script

Open your .bashrc file located in ~/.bashrc. .bashrc file is read whenever you login to the system. Add the below line to the end of the file.
alias sf='/usr/local/bin/somefile.sh'
then re login or run source .bashrc

If you're on a GNU system, you could use the "alternatives" system:
dir=/usr/local/bin
sudo update-alternatives --install $dir/sf somefile $dir/somefile.sh 10
This creates 2 symbolic links:
/usr/local/bin/sf -> /etc/alternatives/somefile
/etc/alternatives/somefile -> /usr/local/bin/somefile.sh

Related

how can i make my bash script (.sh) to run locally as a bash command? [duplicate]

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.

How do I properly set aliases in a bash script (Ubuntu 17.04)?

I have this script called menal in my ~/bin directory:
#!/bin/sh
alias mendir='cd ~/projects/myproject'
It has executable property and I expect that when I run it it sets an appropiate alias for cd command for the terminal session. But it doesn't. When I type $ menal in terminal it shows no error, but when I try $ mendir after that I get
No command 'mendir' found, did you mean:
Command 'menhir' from package 'menhir' (universe)
mendir: command not found
When I type
$ alias mendir='cd ~/projects/myproject'
$ mendir
in terminal, it works.
What am I doing wrong? Is it a script scope issue or something?
Yes, it's a scope problem. Calling it the following way won't produce the result you expect:
./bin/menal
If you want the alias to persist, use source:
source ./bin/menal
You can add it to your .bash_profile.
alias mendir='cd ~/projects/myproject'
then do source ~/.bash_profile
It should create the alias and also will work on every login.

Creating aliases in .bash_profile that run a shell script

So I have a script called spotlyrics.sh that I want to be able to run using the command "lyrics" in the terminal.
I have opened up my .bash_profile and am wondering how I can create the alis which 1) finds the script and then 2) executes it
The file is inside a folder called bash at the following path
/Users/username/Documents/bash
What I have so far (inside my bash profile), which doesn't work because I guess it's not "executing" the script.
alias spotlyrics=“/Users/username/Documents/bash/spotlyrics.sh“
I get the following error when running "spotlyrics" in the terminal:
-bash: “/Users/username/Documents/bash/spotlyrics.sh“: No such file or directory
Would love some help, thanks!
You've been editing your .bash_profile with something that is not a proper text editor. The quotation marks are not ASCII, and therefore not actually quotation marks as far as the shell is concerned.
Instead of beating around the bush with aliasing a script to a name it mostly already has, why not put the script in a directory in PATH and let it be its own command?
mkdir ~/bin
echo 'PATH+=:$HOME/bin' >> ~/.bashrc
mv "/path/to/spotlyrics.sh" ~/bin/spotlyrics && chmod +x ~/bin/spotlyrics
Then restart the shell (log out and back in) and you won't need the alias.
Well, the shell scripts are not executable by just calling it's name, they should be run using "source" command(in case of not c-shell, dot command(.) can also be used).So while adding an alias in .bashrc or .bash_profile for running a shell script append source command before the path to the shell script.
In your case probably this should work:`
alias spotlyrics='source /Users/username/Documents/bash/spotlyrics.sh'`
Please let me know if it doesn't work. Because it worked for me.

.bash_history does not update in Git for Windows (git bash)

I am using Git for Windows (ver. 1.7.8-preview20111206) and even though I have a .bash_history file in my HOME folder, it never automatically gets updated. When I start Git Bash, I can see in the history commands that I manually added to the .bash_history file, but it does not get updated automatically.
I used the shopt -s histappend command to make sure that the history gets saved every time I close the shell, but it does not work.
If I manually use the history -w command, then my file gets updated, but I would want to understand why the shopt command does not work as I understand it should.
Anyone can tell me why is this behavior happening?
I put this in my ~/.bash_profile
PROMPT_COMMAND='history -a'
Create the following files
~/.bash_profile
~/.bashrc
And put the following line in both of them
PROMPT_COMMAND='history -a'
To do this from the console (Git Bash) itself, use the following commands:
echo "PROMPT_COMMAND='history -a'" >> ~/.bash_profile
echo "PROMPT_COMMAND='history -a'" >> ~/.bashrc
What history -a means
From the history --help command
-a append history lines from this session to the history file
What is PROMPT_COMMAND?
Bash provides an environment variable called PROMPT_COMMAND. The contents of this variable are executed as a regular Bash command just before Bash displays a prompt.
Difference between .bash_profile and .bashrc
.bash_profile is executed for login shells, while .bashrc is executed for interactive non-login shells.
When you login (type username and password) via console, either sitting at the machine, or remotely via ssh: .bash_profile is executed to configure your shell before the initial command prompt.
But, if you’ve already logged into your machine and open a new terminal window (xterm) then .bashrc is executed before the window command prompt. .bashrc is also run when you start a new bash instance by typing /bin/bash in a terminal.
On OS X, Terminal by default runs a login shell every time, so this is a little different to most other systems, but you can configure that in the preferences.
References
https://www.tldp.org/HOWTO/Bash-Prompt-HOWTO/x264.html
https://apple.stackexchange.com/questions/51036/what-is-the-difference-between-bash-profile-and-bashrc
As it was said here, to save git bash history on Windows you must not close the terminal with X button. Use exit command instead. History of commands will be saved then regardless of configuration mentioned in the accepted answer.
If you're using Git bash in VSCode please see C.M.'s comment above.
This worked for running git's bash in Visual Studio Code, but I had to put it ~/.bashrc not ~/.bash_profile. – C.M. Jul 29 at 14:43
This solved it for me.
There is a more complete answer on Unix Stackexchange, by Pablo R. and LinuxSecurityFreak. Add the following to your ~/.bashrc:
# Avoid duplicates
HISTCONTROL=ignoredups:erasedups
# When the shell exits, append to the history file instead of overwriting it
shopt -s histappend
# After each command, append to the history file and reread it
PROMPT_COMMAND="${PROMPT_COMMAND:+$PROMPT_COMMAND$'\n'}history -a; history -c; history -r"
Please be careful, though:
The problem with this PROMPT_COMMAND solution is that the numbers for each history item changes after each command. For example, if you type history(1) ls (2) rm, then you do !1 to repeat (1), the history number might change and might run the rm command. Chris Kimpton
If you use git bash for windows 8, just put this in your ~/.bash_logout file:
history > .bash_history
Obviously you need a ~/.bash_history file.
Regards.
For me what worked was going into C:\Users\MY_USER\ and deleting the .bash_profile file.
Ps: I am using windows 10
I am using Windows 10 for me it was a permission problem, my temporary solution was to add Everyone group and give it Full control on ~/.bash_history file.
By the way, for those using the Portable version of Git for Windows, there's no need to create .bash_profile or .bashrc. Simply add to C:<path to your Git Portable folder>\etc\bash.bashrc:
PROMPT_COMMAND='history -a'
Found an answer in another post : https://superuser.com/questions/555310/bash-save-history-without-exit
If you want to have an history updated between two terminals.
As a window user I created a file .bash_profile inside my user folder. And then I add the following content : PROMPT_COMMAND='history -a;history -c;history -r'
Just run this in your git bash
echo 'HISTFILE=$HOME/.bash_history' >> $HOME/.bashrc

How do I execute a bash script in Terminal?

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.

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