I have made a few bash scripts that I have saved to individual folders. I have Windows 10. The scripts have functions that executes commands in bash. I am now able to execute these .sh scripts from any directory, since I have added the folders they are saved in to the path variable. But I want to make it even easier for me, and be able to only have to type the function in the bash console to execute the command.
This is an example of one of the scripts. It is saved as file_lister.sh. I am able to run this by typing "file_lister.sh" but I want to run it by only typing the function name in the script, which is "list_files". How do I do this? Thanks in advance.
#!/bin/bash
function list_files(){
cp C:/Users/jmell/OneDrive/projects/file_lister/file_lister.py file_lister.py
python file_lister.py
cwd=$(pwd)
if [ $cwd != "/c/Users/jmell/OneDrive/projects/file_lister" ]
then
rm file_lister.py
fi
}
list_files
Unless you source all of your scripts (e.g. in your .bashrc file), the functions won't be defined. However, your function is doing a lot of extra work that it really shouldn't be. The example script can be reduced to
#!/bin/bash
python C:/Users/jmell/OneDrive/projects/file_lister/file_lister.py
Better, yet, keep in mind that the shebang line is read and stripped off by the shell. It specifies the interpreter to use. Instead of creating a wrapper script, add the following line to file_lister.py:
#!/path/to/python
At that point, I'd also recommend renaming file_lister.py to just file_lister.
Related
I want to make a file that runs a script, then deletes itself. I know that its root would most likely be "~/Library/Downloads/filename.app". How would I go about having it self destruct? I'm working in script editor.
I'm not sure if I understand correctly as shell script would traditionally have .sh suffix instead of .app one (if any) and I'm not familiar with anything that I'd call "script editor", but alas here's my solution.
If you are in bash environment, you can make use of the BASH_SOURCE array. Provided that you didn't change the current working directory, you can directly call
rm "${BASH_SOURCE[0]}"
(or just rm "$BASH_SOURCE").
If you are using cd or make larger script, it might be advisable to save fully resolved path to the script at the beginning and remove that file at the end (not somewhere in the middle as running bash scripts are NOT independent on their source files*) like so:
#!/bin/bash
self=$(realpath "${BASH_SOURCE[0]}")
#
# code so ugly I want to delete it when I'm done
#
rm "$self"
*Edit shell script while it's running
I am trying to execute a shell script for automating the process rather than manually running the python script. But i am getting the error folder not found.
cd /home/gaurav/AndroPyTool
export ANDROID_HOME=$HOME/android-sdk-linux/
export PATH=$PATH:$ANDROID_HOME/tools
export PATH=$PATH:$ANDROID_HOME/platform-tools
source ~/.bashrc
source droidbox_env/bin/activate
alias mycd='cd /home/gaurav/AndroPyTool/test'
mycd
pwd
python androPyTool.py -all -csv EXPORTCSV.csv -s mycd
>>>> AndroPyTool -- STEP 1: Filtering apks
Folder not found!
This is the error i am getting because the script is not able to find the path that i have provided above.
The part after "-s" in the code represents the folder path where the file stored.
The issue here is that you are not passing the path to the python program. The python program is not aware of bash aliases and bash will only expand aliases when it is interpreting the token as a command.
When bash reads python androPyTool.py -all -csv EXPORTCSV.csv -s mycd It interprets python as the command and all other space separated tokens are arguments that will be passed into python. Python then invokes androPyTool.py and passes the subsequent arguments to that script. So the program is receiving literally mycd as the argument for -s.
Moreover, even if mycd is expanded, it wouldn't be the correct argument for -s. androPyTool.py is expecting just the /path/to/apks, not cd /path/to/apks/.
I don't really think that using the alias in this script makes much sense. It actually makes the script harder to read and understand. If you want to wrap a command, I recommend defining a function, and occasionally you can use variable expansion (but that mixes code and data which can lead to issues). EDIT: As has been pointed out in the comments, aliases are disabled for scripts.
Finally there are some other suspicious issues with your script. Mainly, why are you sourcing .bashrc? If this script is run by you in your user's environment, .bashrc will already be sourced and there is no need to re-source it. On the other hand, if this is not intended to be run in your environment, and there is something in the .bashrc file that you need in your script, I recommend pulling just that out and nothing else.
But the most immediate issue that I can see is that sourcing .bashrc after you modify path runs the risk of overwriting the changes to PATH you just made. Depending on the contents of the .bashrc file, sourcing it may not be idempotent, meaning that running it more than once could have side effects. Finally, anything could get thrown in that .bashrc file down the road since that's what its for. So now your script may depend on something that likely will be changing. This opens up the possibility that bugs will creep in to your script unexpectedly.
Is there a way to add bash functions to the $PATH, or to the bash shell, without requiring an end-user to source them manually?
In other words, if we have a software library that exports only bash functions, we normally require the end-user to source the bash scripts with
. "$HOME/.the_scripts/"*.sh
and then using them. But is there a way to somehow get the bash functions into the shell without requiring the user to add a line of code to ~/.bashrc or ~/.bash_profile, etc?
What am I trying to do? I am trying to obviate the need for users to add a call to source a bash script for a library they just installed.
One suggestion I got was to write a container script, to a folder, where that folder is already in the $PATH.
Say I have a script like so:
#!/usr/bin/env bash
my_func(){
echo "this is my func, $1, $2, $3"
export foo="my_func"
}
my_func a b c
I could write that script to a folder in $PATH and then execute the script, which will then call the bash function(s).
Not sure how great/universal a solution this is, but it would work for some use cases I suppose. This will not work if you want to export env variables to the current shell, etc, because the bash function(s) would be run in a subshell as far as I know from the command line / current script.
If you read about the Bash Startup Files, you notice that /etc/profile is one of the files that is processed. If you read that file, you'll see that it sources all *.sh files in /etc/profile.d
If you can have your script libraries installed in /etc/profile.d, the functions will be available for all interactive login shell sessions.
I have a shell script on a mac (OSX 10.9) named msii810161816_TMP_CMD with the following content.
matlab
When I execute it, I get
./msii810161816_TMP_CMD: line 1: matlab: command not found
However, when I type matlab into the shell directly it starts as normal. How can it be that the same command works inside the shell but not inside a shell script? I copy-pasted the command directly from the script into the shell and it worked ...
PS: When I replace the content of the script with
echo matlab
I get the desired result, so I can definitely execute the shell script (I use ./msii810161816_TMP_CMD)
Thanks guys!
By default, aliases are not expanded in non-interactive shells, which is what shell scripts are. Aliases are intended to be used by a person at the keyboard as a typing aid.
If your goal is to not have to type the full path to matlab, instead of creating an alias you should modify your $PATH. Add /Applications/MATLAB_R2014a.app/bin to your $PATH environment variable and then both you and your shell scripts will be able to simply say
matlab
This is because, as commenters have stated, the PATH variable inside of the shell executing the script does not include the directory containing the matlab executable.
When a command name is used, like "matlab", your shell looks at every directory in the PATH in order, searching for one containing an executable file with the name "matlab".
Without going into too much detail, the PATH is determined by the shell being invoked.
When you execute bash, it combines a global setting for basic directories that must be in the PATH with any settings in your ~/.bashrc which alter the PATH.
Most likely, you are not running your script in a shell where the PATH includes matlab's directory.
To verify this, you can take the following steps:
Run which matlab. This will show you the path to the matlab executable.
Run echo "$PATH". This will show you your current PATH settings. Note that the directory from which matlab is included in the colon-separated list.
Add a line to the beginning of your script that does echo "$PATH". Note that the directory from which matlab is not included.
To resolve this, ensure that your script is executed in a shell that has the needed directory in the PATH.
You can do this a few ways, but the two most highly recommended ones would be
Add a shebang line to the start of your script. Assuming that you want to run it with bash, do #!/bin/bash or whatever the path to your bash interpreter is.
The shebang line is not actually fully standardized by POSIX, so BSD-derived systems like OSX will happily handle multiple arguments to the shebanged executable, while Linux systems pass at most one argument.
In spite of this, the shebang is an easy and simple way to document what should be used to execute the script, so it's a good solution.
Explicitly invoke your script with a shell as its interpreter, as in bash myscript.sh or tcsh myscript.sh or even sh myscript.sh
This is not incompatible with using a shebang line, and using both is a common practice.
I believe that the default shell on OSX is always bash, so you should start by trying with that.
If these instructions don't help, then you'll have to dig deeper to find out why or how the PATH is being altered between the calling context and the script's internal context.
Ultimately, this is almost certainly the source of your issue.
I wish to replace my failing memory with a very small shell script.
#!/bin/sh
if ! [ –a $1.sav ]; then
mv $1 $1.sav
cp $1.sav $1
fi
nano $1
is intended to save the original version of a script. If the original has been preserved before, it skips the move-and-copy-back (and I use move-and-copy-back to preserve the original timestamp).
This works as intended if, after I make it executable with chmod I launch it from within the directory where I am editing, e.g. with
./safe.sh filename
However, when I move it into /usr/bin and then I try to run it in a different directory (without the leading ./) it fails with:
*-bash: /usr/bin/safe.sh: /bin/sh: bad interpreter: Text file busy*
My question is, when I move this script into the path (verified by echo $PATH) why does it then fail?
D'oh? Inquiring minds want to know how to make this work.
The . command is not normally used to run standalone scripts, and that seems to be what is confusing you. . is more typically used interactively to add new bindings to your environment (e.g. defining shell functions). It is also used to similar effect within scripts (e.g. to load a script "library").
Once you mark the script executable (per the comments on your question), you should be able to run it equally well from the current directory (e.g. ./safe.sh filename) or from wherever it is in the path (e.g. safe.sh filename).
You may want to remove .sh from the name, to fit with the usual conventions of command names.
BTW: I note that you mistakenly capitalize If in the script.
The error bad interpreter: Text file busy occurs if the script is open for write (see this SE question and this SF question). Make sure you don't have it open (e.g. in a editor) when attempting to run it.