I don't really know how to ask this question but I can describe what I want to achieve. I would update any edits that would be suggested.
I have a python module that makes use of some command line arguments. Using the module requires some initial setup outside of the python interpreter. The python file that does the setup runs fine, but the problem is that I have to dig through the python installation to find where that file is located i.e. I have to do python full-path-to-setup-script.py -a argA -b argB etc.I would like to call the setup script like this
some-setup-command -a argA -b argB etc.
I want to achieve something like
workon environmnent_name as in the virtualenv module or
pipenv install as in the pipenv module.
I know both of the above commands call a script of some kind (whether bash or python). I've tried digging through the source codes of virtualenv and pipenv without any success.
I would really appreciate if someone could point me to any necessary resource for coding such programs.
If full-path-to-setup-script.py is executable and has a proper shebang line
#! /usr/bin/env python
then you can
ln -s full-path-to-setup-script.py ~/bin/some-command
considering ~/bin exists and is in your PATH,
and you'll be able to invoke
some-command -a argA -b argB
It's a bit difficult to understand what you're looking for, but python -m is my best guess.
For example, to make a new Jupyter kernel, we call
python -m ipykernel arg --option --option
Where arg is the CLI argument and option is a CLI option, and ipykernel is the module receiving the args and options.
Commands that are callable from the command prompt are located in one of the directories in your system's PATH variable. If you are on Windows, you see the locations via:
echo %PATH%
Or if you want a nicer readout:
powershell -c "$env:path -split(';')"
One solution is to create a folder, add it to your system's PATH, and then create a callable file that you can run. In this example we will create a folder in your user profile, add it to the path, then create a callable file in that folder.
mkdir %USERPROFILE%\path
set PATH=%PATH%%USERPROFILE%\path;
setx PATH %PATH%
In the folder %USERPROFILE%\path, we create a batch file with following content:
# file name:
# some-command.bat
#
python C:\full\path\to\setup-script.py %*
Now you should be able to call
some-command -a argA -b argB
And the batch file will call python with python script and pass the arguments you added.
Looking at the above answers, I see no one has mentioned this:
You can of course compile the python file and give executable permissions with
chmod +x filename.py
and then run it as
./filename.py -a argA -b argB ...
Moreover, you can also remove the extention .py (since it is an executable now) and then run it only as
./filename -a argA -b argB ...
I'm trying to write a small script to change the current directory to my project directory:
#!/bin/bash
cd /home/tree/projects/java
I saved this file as proj, added execute permission with chmod, and copied it to /usr/bin. When I call it by:
proj, it does nothing. What am I doing wrong?
Shell scripts are run inside a subshell, and each subshell has its own concept of what the current directory is. The cd succeeds, but as soon as the subshell exits, you're back in the interactive shell and nothing ever changed there.
One way to get around this is to use an alias instead:
alias proj="cd /home/tree/projects/java"
You're doing nothing wrong! You've changed the directory, but only within the subshell that runs the script.
You can run the script in your current process with the "dot" command:
. proj
But I'd prefer Greg's suggestion to use an alias in this simple case.
The cd in your script technically worked as it changed the directory of the shell that ran the script, but that was a separate process forked from your interactive shell.
A Posix-compatible way to solve this problem is to define a shell procedure rather than a shell-invoked command script.
jhome () {
cd /home/tree/projects/java
}
You can just type this in or put it in one of the various shell startup files.
The cd is done within the script's shell. When the script ends, that shell exits, and then you are left in the directory you were. "Source" the script, don't run it. Instead of:
./myscript.sh
do
. ./myscript.sh
(Notice the dot and space before the script name.)
To make a bash script that will cd to a select directory :
Create the script file
#!/bin/sh
# file : /scripts/cdjava
#
cd /home/askgelal/projects/java
Then create an alias in your startup file.
#!/bin/sh
# file /scripts/mastercode.sh
#
alias cdjava='. /scripts/cdjava'
I created a startup file where I dump all my aliases and custom functions.
Then I source this file into my .bashrc to have it set on each boot.
For example, create a master aliases/functions file: /scripts/mastercode.sh
(Put the alias in this file.)
Then at the end of your .bashrc file:
source /scripts/mastercode.sh
Now its easy to cd to your java directory, just type cdjava and you are there.
You can use . to execute a script in the current shell environment:
. script_name
or alternatively, its more readable but shell specific alias source:
source script_name
This avoids the subshell, and allows any variables or builtins (including cd) to affect the current shell instead.
Jeremy Ruten's idea of using a symlink triggered a thought that hasn't crossed any other answer. Use:
CDPATH=:$HOME/projects
The leading colon is important; it means that if there is a directory 'dir' in the current directory, then 'cd dir' will change to that, rather than hopping off somewhere else. With the value set as shown, you can do:
cd java
and, if there is no sub-directory called java in the current directory, then it will take you directly to $HOME/projects/java - no aliases, no scripts, no dubious execs or dot commands.
My $HOME is /Users/jleffler; my $CDPATH is:
:/Users/jleffler:/Users/jleffler/mail:/Users/jleffler/src:/Users/jleffler/src/perl:/Users/jleffler/src/sqltools:/Users/jleffler/lib:/Users/jleffler/doc:/Users/jleffler/work
Use exec bash at the end
A bash script operates on its current environment or on that of its
children, but never on its parent environment.
However, this question often gets asked because one wants to be left at a (new) bash prompt in a certain directory after execution of a bash script from within another directory.
If this is the case, simply execute a child bash instance at the end of the script:
#!/usr/bin/env bash
cd /home/tree/projects/java
echo -e '\nHit [Ctrl]+[D] to exit this child shell.'
exec bash
To return to the previous, parental bash instance, use Ctrl+D.
Update
At least with newer versions of bash, the exec on the last line is no longer required. Furthermore, the script could be made to work with whatever preferred shell by using the $SHELL environment variable. This then gives:
#!/usr/bin/env bash
cd desired/directory
echo -e '\nHit [Ctrl]+[D] to exit this child shell.'
$SHELL
I got my code to work by using. <your file name>
./<your file name> dose not work because it doesn't change your directory in the terminal it just changes the directory specific to that script.
Here is my program
#!/bin/bash
echo "Taking you to eclipse's workspace."
cd /Developer/Java/workspace
Here is my terminal
nova:~ Kael$
nova:~ Kael$ . workspace.sh
Taking you to eclipe's workspace.
nova:workspace Kael$
simply run:
cd /home/xxx/yyy && command_you_want
When you fire a shell script, it runs a new instance of that shell (/bin/bash). Thus, your script just fires up a shell, changes the directory and exits. Put another way, cd (and other such commands) within a shell script do not affect nor have access to the shell from which they were launched.
You can do following:
#!/bin/bash
cd /your/project/directory
# start another shell and replacing the current
exec /bin/bash
EDIT: This could be 'dotted' as well, to prevent creation of subsequent shells.
Example:
. ./previous_script (with or without the first line)
On my particular case i needed too many times to change for the same directory.
So on my .bashrc (I use ubuntu) i've added the
1 -
$ nano ~./bashrc
function switchp
{
cd /home/tree/projects/$1
}
2-
$ source ~/.bashrc
3 -
$ switchp java
Directly it will do: cd /home/tree/projects/java
Hope that helps!
It only changes the directory for the script itself, while your current directory stays the same.
You might want to use a symbolic link instead. It allows you to make a "shortcut" to a file or directory, so you'd only have to type something like cd my-project.
You can combine Adam & Greg's alias and dot approaches to make something that can be more dynamic—
alias project=". project"
Now running the project alias will execute the project script in the current shell as opposed to the subshell.
You can combine an alias and a script,
alias proj="cd \`/usr/bin/proj !*\`"
provided that the script echos the destination path. Note that those are backticks surrounding the script name.
For example, your script could be
#!/bin/bash
echo /home/askgelal/projects/java/$1
The advantage with this technique is that the script could take any number of command line parameters and emit different destinations calculated by possibly complex logic.
to navigate directories quicky, there's $CDPATH, cdargs, and ways to generate aliases automatically
http://jackndempsey.blogspot.com/2008/07/cdargs.html
http://muness.blogspot.com/2008/06/lazy-bash-cd-aliaes.html
https://web.archive.org/web/1/http://articles.techrepublic%2ecom%2ecom/5100-10878_11-5827311.html
In your ~/.bash_profile file. add the next function
move_me() {
cd ~/path/to/dest
}
Restart terminal and you can type
move_me
and you will be moved to the destination folder.
You can use the operator && :
cd myDirectory && ls
While sourcing the script you want to run is one solution, you should be aware that this script then can directly modify the environment of your current shell. Also it is not possible to pass arguments anymore.
Another way to do, is to implement your script as a function in bash.
function cdbm() {
cd whereever_you_want_to_go
echo "Arguments to the functions were $1, $2, ..."
}
This technique is used by autojump: http://github.com/joelthelion/autojump/wiki to provide you with learning shell directory bookmarks.
You can create a function like below in your .bash_profile and it will work smoothly.
The following function takes an optional parameter which is a project.
For example, you can just run
cdproj
or
cdproj project_name
Here is the function definition.
cdproj(){
dir=/Users/yourname/projects
if [ "$1" ]; then
cd "${dir}/${1}"
else
cd "${dir}"
fi
}
Dont forget to source your .bash_profile
This should do what you want. Change to the directory of interest (from within the script), and then spawn a new bash shell.
#!/bin/bash
# saved as mov_dir.sh
cd ~/mt/v3/rt_linux-rt-tools/
bash
If you run this, it will take you to the directory of interest and when you exit it it will bring you back to the original place.
root#intel-corei7-64:~# ./mov_dir.sh
root#intel-corei7-64:~/mt/v3/rt_linux-rt-tools# exit
root#intel-corei7-64:~#
This will even take you to back to your original directory when you exit (CTRL+d)
I did the following:
create a file called case
paste the following in the file:
#!/bin/sh
cd /home/"$1"
save it and then:
chmod +x case
I also created an alias in my .bashrc:
alias disk='cd /home/; . case'
now when I type:
case 12345
essentially I am typing:
cd /home/12345
You can type any folder after 'case':
case 12
case 15
case 17
which is like typing:
cd /home/12
cd /home/15
cd /home/17
respectively
In my case the path is much longer - these guys summed it up with the ~ info earlier.
As explained on the other answers, you have changed the directory, but only within the sub-shell that runs the script. this does not impact the parent shell.
One solution is to use bash functions instead of a bash script (sh); by placing your bash script code into a function. That makes the function available as a command and then, this will be executed without a child process and thus any cd command will impact the caller shell.
Bash functions :
One feature of the bash profile is to store custom functions that can be run in the terminal or in bash scripts the same way you run application/commands this also could be used as a shortcut for long commands.
To make your function efficient system widely you will need to copy your function at the end of several files
/home/user/.bashrc
/home/user/.bash_profile
/root/.bashrc
/root/.bash_profile
You can sudo kwrite /home/user/.bashrc /home/user/.bash_profile /root/.bashrc /root/.bash_profile to edit/create those files quickly
Howto :
Copy your bash script code inside a new function at the end of your bash's profile file and restart your terminal, you can then run cdd or whatever the function you wrote.
Script Example
Making shortcut to cd .. with cdd
cdd() {
cd ..
}
ls shortcut
ll() {
ls -l -h
}
ls shortcut
lll() {
ls -l -h -a
}
If you are using fish as your shell, the best solution is to create a function. As an example, given the original question, you could copy the 4 lines below and paste them into your fish command line:
function proj
cd /home/tree/projects/java
end
funcsave proj
This will create the function and save it for use later. If your project changes, just repeat the process using the new path.
If you prefer, you can manually add the function file by doing the following:
nano ~/.config/fish/functions/proj.fish
and enter the text:
function proj
cd /home/tree/projects/java
end
and finally press ctrl+x to exit and y followed by return to save your changes.
(NOTE: the first method of using funcsave creates the proj.fish file for you).
You need no script, only set the correct option and create an environment variable.
shopt -s cdable_vars
in your ~/.bashrc allows to cd to the content of environment variables.
Create such an environment variable:
export myjava="/home/tree/projects/java"
and you can use:
cd myjava
Other alternatives.
Note the discussion How do I set the working directory of the parent process?
It contains some hackish answers, e.g.
https://stackoverflow.com/a/2375174/755804 (changing the parent process directory via gdb, don't do this) and https://stackoverflow.com/a/51985735/755804 (the command tailcd that injects cd dirname to the input stream of the parent process; well, ideally it should be a part of bash rather than a hack)
It is an old question, but I am really surprised I don't see this trick here
Instead of using cd you can use
export PWD=the/path/you/want
No need to create subshells or use aliases.
Note that it is your responsibility to make sure the/path/you/want exists.
I have to work in tcsh, and I know this is not an elegant solution, but for example, if I had to change folders to a path where one word is different, the whole thing can be done in the alias
a alias_name 'set a = `pwd`; set b = `echo $a | replace "Trees" "Tests"` ; cd $b'
If the path is always fixed, the just
a alias_name2 'cd path/you/always/need'
should work
In the line above, the new folder path is set
This combines the answer by Serge with an unrelated answer by David. It changes the directory, and then instead of forcing a bash shell, it launches the user's default shell. It however requires both getent and /etc/passwd to detect the default shell.
#!/usr/bin/env bash
cd desired/directory
USER_SHELL=$(getent passwd <USER> | cut -d : -f 7)
$USER_SHELL
Of course this still has the same deficiency of creating a nested shell.
I'm making a python script for Travis CI.
.travis.yml
...
script:
- support/travis-build.py
...
The python file travis-build.py is something like this:
#!/usr/bin/env python
from subprocess import check_call
...
check_call(r"mv !(my_project|cmake-3.0.2-Darwin64-universal) ./my_project/final_folder", shell=True)
...
When Travis building achieves that line, I'm getting an error:
/bin/sh: 1: Syntax error: "(" unexpected
I just tried a lot of different forms to write it, but I get the same result. Any idea?
Thanks in advance!
Edit
My current directory layout:
- my_project/final_folder/
- cmake-3.0.2-Darwin64-universal/
- fileA
- fileB
- fileC
I'm trying with this command to move all the current files fileA, fileB and fileC, excluding my_project and cmake-3.0.2-Darwin64-universal folders into ./my_project/final_folder. If I execute this command on Linux shell, I get my aim but not through check_call() command.
Note: I can't move the files one by one, because there are many others
I don't know which shell Travis are using by default because I don't specify it, I only know that if I write the command in my .travis.yml:
.travis.yml
...
script:
# Here is the previous Travis code
- mv !(my_project|cmake-3.0.2-Darwin64-universal) ./my_project/final_folder
...
It works. But If I use the script, it fails.
I found this command from the following issue:
How to use 'mv' command to move files except those in a specific directory?
You're using the bash feature extglob, to try to exclude the files that you're specifying. You'll need to enable it in order to have it exclude the two entries you're specifying.
The python subprocess module explicitly uses /bin/sh when you use shell=True, which doesn't enable the use of bash features like this by default (it's a compliance thing to make it more like original sh).
If you want to get bash to interpret the command; you have to pass it to bash explicitly, for example using:
subprocess.check_call(["bash", "-O", "extglob", "-c", "mv !(my_project|cmake-3.0.2-Darwin64-universal) ./my_project/final_folder"])
I would not choose to do the job in this manner, though.
Let me try again: in which shell do you expect your syntax !(...) to work? Is it bash? Is it ksh? I have never used it, and a quick search for a corresponding bash feature led nowhere. I suspect your syntax is just wrong, which is what the error message is telling you. In that case, your problem is entirely independent form python and the subprocess module.
If a special shell you have on your system supports this syntax, you need to make sure that Python is using the same shell when invoking your command. It tells you which shell it has been using: /bin/sh. This is usually just a link to the real shell executable. Does it point to the same shell you have tested your command in?
Edit: the SO solution you referenced contains the solution in the comments:
Tip: Note however that using this pattern relies on extglob. You can
enable it using shopt -s extglob (If you want extended globs to be
turned on by default you can add shopt -s extglob to .bashrc)
Just to demonstrate that different shells might deal with your syntax in different ways, first using bash:
$ !(uname)
-bash: !: event not found
And then, using /bin/dash:
$ !(uname)
Linux
The argument to a subprocess.something method must be a list of command line arguments. Use e.g. shlex.split() to make the string be split into correct command line arguments:
import shlex, subprocess
subprocess.check_call( shlex.split("mv !(...)") )
EDIT:
So, the goal is to move files/directories, with the exemption of some file(s)/directory(ies). By playing around with bash, I could get it to work like this:
mv `ls | grep -v -e '\(exclusion1\|exclusion2\)'` my_project
So in your situation that would be:
mv `ls | grep -v -e '\(myproject\|cmake-3.0.2-Darwin64-universal\)'` my_project
This could go into the subprocess.check_call(..., shell=True) and it should do what you expect it to do.
I have a simple bash script that allows cron to execute a series of Python scripts in a virtualenv. The script keeps raising No such file or directory errors.
~/nightly.sh works fine:
#!/bin/bash
source virt_env/myproject/bin/activate
cd virt_env/myproject/main
python script1.py
python script2.py
I want to keep everything in ~/virt_env/myproject/main/ to simplify deployment. I thought I could call bash virt_env/myproject/main/nightly.sh on this:
#!/bin/bash
MAINDIR=`dirname $0`
cd $MAINDIR
source ../bin/activate
python script1.py
python script2.py
but I get the No such file or directory. If I manually cd to ~/virt_env/myproject/main/, then I can run the main commands no problem. Clearly I'm missing something about how dirname and cd work in this context.
How can I point bash at the right place?
Solution
As proposed in the accepted answer, it's best to avoid calling cd from within the script and use an explicit path variable instead. Here's the working version of virt_env/myproject/main/nightly.sh:
#!/bin/bash
MAINDIR=`dirname $0`
echo "The main directory is" $MAINDIR
# Activate virtual environment
source $MAINDIR/../bin/activate
# Run Python scripts
python $MAINDIR/python1.py
python $MAINDIR/python2.py
Because the Python scripts are now called from an arbitrary path, I needed to update the python scripts to be smarter about path awareness as well.
This code fails because os.path.basename omits path information:
# works when called with "python python1.py"
# fails when called with "python $MAINDIR/python1.py"
CONFIG_FILE = os.path.basename(__file__)[:-3] + ".config"
f = open(CONFIG_FILE,"r")
Updating it to use os.path.abspath fixes the problem:
# works regardless of how it is called
CONFIG_FILE = os.path.abspath(__file__)[:-3] + ".config"
f = open(CONFIG_FILE,"r")
Perhaps it would simply be better to eliminate the 'cd' command. Invoke everything from a full path specification. In your example add $MAINDIR/ to the executables.
Your bash script can then be in any directory where the executables are reachable. You are not exposed to the problems of what happens when cd fails.
Example:
cd yourdir
rm -f yourglob # oops things got removed from where you started if yourdir did not exist.
Two things:
Are you sure you know what the dirname command is doing? It's going to remove the top-level directory as well as the leading slash on whatever you call it on. I would make absolutely sure that the output of dirname is exactly what you think it is.
For example, /home/user/ will output /home.
You're using ~, which references the $HOME variable in your environment. You didn't mention where the cron is listed, but make sure it's not being run as a different user. Root's ~ and your ~ will be two completely different directories.
That's all I can think of. I hope that helps!
Add echo $MAINDIR after
MAINDIR=`dirname $0`
cd $MAINDIR
So you can see, if the contents of MAINDIR is correct.
Also you can run sh with -x or add set -x to the beginning of the script to see what happens.