.Deb package postinst file not appending data to ~/.bashrc - linux

I have this very simple postinst file for a .Deb package:
#!/bin/sh
echo 'alias command_pandora="sudo /usr/local/bin/pandora"' >> ~/.bashrc
echo 'Pandora Storage Server Installation complete.'
When I run it I even get the 'Pandora Storage Server Installation complete.' message, but nothing is appended to ~/.bashrc; nevertheless when I run this command alone in the terminal:
echo 'alias command_pandora="sudo /usr/local/bin/pandora"' >> ~/.bashrc
It does work. I already tried modifying the file permisions for ~/.bashrc but still get the same result. I also tried running a separate script with the same content and running it and it also works, so it seems to be related to dpkg.
Why is the content not being appended?

The postinst script runs as root. Package installation is a system installation utility; it should absolutely not modify users' private files, including those of root.
Tangentially, defining an alias seems like the wrong solution to your problem. Generally, prefer functions or shell scripts over aliases.
If the tool requires privileged access through sudo, perhaps refactor it to run itself with sudo (maybe with a check to only do this when it is connected to a terminal, to prevent it from hanging when run unattended).
Or, simply, include /usr/bin/command_pandora in the package with the following contents:
#!/bin/sh
exec sudo /usr/local/bin/pandora "$#"
(Marginally, I suppose it could add something to /etc/skel/.bashrc but this will only create a new alias for users which are created after this change, or users whose .bashrc presciently run source /etc/skel/.bashrc. I don't think that's a good idea, either.)

Related

lzma command not found when executing shell script only under sudo

I am building project source code in a SUSE server.
The project build.sh called "lzma" command to compress kernel.
The project build.sh need "sudo" to get access to some system command.
But I has tried to execute "sudo ./build.sh", and the shell always report error: "lzma: command not found."
I could execute "lzma" in shell with my user account. It works fine.
I also write a test shell script named "test.sh" which calls "lzma" command.
I found that it fails with same error message if I excute "test.sh" with "sudo" .
But if I execute "test.sh" without "sudo", it works fine.
Why ?
"Command not found" within sudo is almost invariably the result of an environment variable such as PATH, LD_LIBRARY_PATH (if what's missing is not the executable but a shared library it requires) or the like being altered.
You can pass working values through your environment variables through explicitly:
sudo PATH="$PATH" ./test.sh
Sudo uses a different Path then your user account.
EDIT (see comments)
Try and execute:
type lzma
Say the output reads something like '/usr/bin/lzma', then just copy that output into your sudo command like (for example):
sudo /usr/bin/lzma
That should do the trick. You should also write the full path of lzma into your shell script if you are to run it as root.
EDIT 2:
Or, as Charles Duffy mentioned in his answer, you could leave all things as is and simply use PATH="$PATH" in your command if you are trying to execute your file as SUDO or as a different user.

bash changing directory when started

I have both Bash on Ubuntu on Windows and Cygwin bash installed on my machine, and both are setup to have the same ~ folder (via /mnt/c/source and /cygdrive/c/source respectively).
When I start Ubuntu's bash prompt via bash --login -i (or just bash --login) from any directory, I get a prompt running from within that directory; however, when I start Cygwin's bash via the same command, the current directory is overridden, and the prompt is always at ~. See the screenshots for a simple example.
My user directory's .bashrc and .bash_profile are of course the same, as both are using the same user directory. I've looked into Cygwin's /etc/bash.bashrc and there doesn't seem to be anything there to change my current directory, and there aren't any other relevant files in /etc.
What could be causing Cygwin's bash to change directory?
you just add a command "cd /dir_you_want" at the bottom of ~/.bashrc in cygwin
I've figured it out, so in case anyone runs into the same issue:
There's one file I neglected to look into, because I didn't know it exists, /etc/profile. In Cygwin, by default it has the following section in it:
# Make sure we start in home unless invoked by CHERE
if [ ! -z "${CHERE_INVOKING}" ]; then
unset CHERE_INVOKING
else
cd "${HOME}" || echo "WARNING: Failed attempt to cd into ${HOME}!"
fi
Disabling that solves the issue of course.

creating a command to go to a specific shortcut

So basically, I just installed ubuntu on bash on my windows PC and every time I have to go to desktop I have to type cd /mnt/c/Users/Name/Desktop. is there a way that I can make a script or command so everytime i type in "desktop" it changes my directory to desktop? I've never done Linux/bash scripting and therefore I have no clue. I just use it for the g++ compiler.
There are many ways to do this:
Create an executable program that runs the command cd /mnt/c/Users/Name/Desktop (this is iain's answer, and a perfectly fine one; the only issue might be that you'll need to either enter the full path for that program every time you run it, or you'll need to put it into a directory that is already included in your $PATH environment variable.)
Create an environment variable that contains the path you'd like, then cd to it cd $DESKTOP.
export DESKTOP="/mnt/c/Users/Name/Desktop"
cd $DESKTOP
You'll likely want to put the creation of this environment variable into your .bashrc or .profile, so it gets created each time you login.
echo 'export DESKTOP="/mnt/c/Users/Name/Desktop"' >> ~/.bashrc
(Note: the above adds it to the end of the .bashrc file. Once you learn more about bash and .bashrc you will probably want to move it to another location in the file.)
Create an alias that does the same thing.
alias mydesk='cd /mnt/c/Users/Name/Desktop'
Again, you'll likely want to add the creation of this alias to your .bashrc or .profile file, so it gets created each time you login:
echo "alias mydesk='cd /mnt/c/Users/Name/Desktop'" >> ~/.bashrc
(Note: the above adds it to the end of the .bashrc file. Once you learn more about bash and .bashrc you will probably want to move it to another location in the file or even a different file completely.)
Assuming that "/mnt/c/Users/Name/" is your home directory, you can just use the shortcut for that, then append "Desktop" to it:
cd ~/Desktop
or
cd $HOME/Desktop
You can give this a try ...
make a file called desktop
Put this into it:
#!/bin/bash
cd /mnt/c/Users/Name/Desktop
close the file and then make it executable.
$ chmod +x desktop
Now by typing . desktop (note the dot) you should be taken to your desktop.
You may also be able to add the script to your path, so that it will run from anywhere in the bash environment; Depending upon how like ubuntu your environment is.

Can't install heroku toolbelt on Linux Mint Path invalid

Attemping
wget -qO- https://toolbelt.heroku.com/install.sh | sh
as instructed by this article yields this message.
Add the Heroku CLI to your PATH using: $ echo 'PATH="/usr/local/heroku/bin:$PATH"' >> ~/.profile
So I type
echo 'PATH="/usr/local/heroku/bin:$PATH"' >> ~/.profile
and I see that the string has been added to the .profile file, located at /home/myusername/
Then I run the command again
wget -qO- https://toolbelt.heroku.com/install.sh | sh
and I still get the same error.
I'm not sure if what current directory I'm running these commands from is important, but I've tried being in the default terminal directory, rather than my specific app, and still the same results.
I found out that the /usr/ directory is directly underneath the / directory, NOT my /home/myusername/ directory so I modified the path to go up two levels, first like so:
PATH="../../usr/local/heroku/bin:$PATH"
But even that didn't seem to work - I don't get the "heroku" command available.
You have to log into linux profile again to activate the ~/.profile script, thus adding the path. Either log out of the linux session, and then lack back in, or restart your computer.
You can also do source ~/.profile, but this will only enable heroku commands in the current terminal, and not work if you close it.

Defining aliases in Cygwin under Windows

I am trying to define some aliases in cygwin, but with no success. I am doing so like this at the end of the .bashrc file.
alias foo='pwd'
I have tried to add this line in a .bashrc file in both inside the home folder of cygwin and in the home folder for the Windows user I am on C:\Users\Nuno\. In both cases I have just appended this line to a copy of the /etc/skel/.bashrc file. In either cases, it didn't work.
I had this working before. I had to reinstall Cygwin and ever since it never worked properly again. I have removed all files (or at least think so, when doing the reinstallation). I have also noticed that in the first install (when it was working) cygwin already was creating .bash files in the home folder. Now, it doesn't.
I am on a machine running Windows 7.
EDIT: My cygwin home folder is set to the Windows home folder C:\Users\Nuno\. I have placed what I think is a valid .bashrc file there, but it still doesn't work.
Thanks in advance.
As me_and already explained what's going on I just want to add a workaround should you for whatever reason not be able or willing to remove Windows' HOME environment variable.
Normally the shortcut for Cygwin executes
C:\cygwin\bin\mintty.exe -i /Cygwin-Terminal.ico -
Instead you can create a batchfile with the following content and start that:
#echo off
set HOME=
start C:\cygwin\bin\mintty.exe -i /Cygwin-Terminal.ico -
That will start a a Cygwin windows whose home directory settings are not overridden by a Windows environment variable.
Your .bashrc file will be loaded from wherever Cygwin Bash thinks your home directory is when it starts. You've mentioned in your edit that you've changed your home directory, but not how, so it's possible you've made a mistake there.
Cygwin will load your home directory from one of two places, and if they differ it can cause problems:
The HOME environment variable. This will be picked up from however you launch Cygwin, so normally from Windows itself. You can see what environment variables you have defined by pressing Win+Pause, going to "Advanced system settings", "Environment Variables…". If "HOME" is in either "User variables" or "System variables", delete it – it's unnecessary and only causes problems.
Cygwin's /etc/passwd file (normally C:\Cygwin\etc\passwd from Windows). This will have a number of lines containing details of each user on the system; the seventh : separated field is the home directory. You can tell which user it's looking at by running whoami from a Cygwin bash shell.
If whoami reports nunos, you should have a line in Cygwin's /etc/passwd that looks something like the following:
nunos:unused:1001:513:U-System\nunos:S-1-2-34-567890-123456-7890123-1001:/home/nunos:/bin/bash
It's that /home/nunos that's important; if it's something different you should probably reset it to that, at which point you want to use the .bashrc in Cygwin's /home/nunos/.
You should also be very wary of directories that contain spaces for this. C:\Users\nunos should be fine, but beware in particular C:\Documents and Settings\nunos, which just won't work with Cygwin.
I had the same issue, where the aliases added to ~/.bashrc didn't work.
It seems that, for some reason, the ~/.bashrc was not executed when launching the console.
I stumbled upon a response that fixes the issues
So, you need to create a .bash_profile file. This one seems to be the default script, and put this code in it, to ensure that the .bashrc is executed.
# ~/.bash_profile: executed by bash for login shells.
if [ -e /etc/bash.bashrc ] ; then
source /etc/bash.bashrc
fi
if [ -e ~/.bashrc ] ; then
source ~/.bashrc
fi
That works for me, just make sure that .bash_profile is executable. (chmod +x ~/.bash_profile)
Here's a really quick and dirty way to do it, but it works fine for most things!
Let's say you want to always run 'ls --color' instead of just 'ls'. Instead of messing around with .bashrc stuff, you can create a simple .bat file that essentially bootlegs the original ls command.
Here's what I did:
cd /bin
echo ls2.exe %* --color > lsNew.bat
mv ls.exe ls2.exe
mv lsNew.bat ls.bat
So now, whenever you type in ls from CMD, you actually are calling ls.bat, which in turn calls ls2.exe --color, the original ls command with the --color flag, along with the rest of the arguments, which are nicely passed through %*.
I had the same problem, but I was using ConEmu to run my console. I had to go into settings and change the settings from this :
set CHERE_INVOKING=1 & %ConEmuDrive%\Programs\Cygwin\bin\sh.exe --login -i -new_console:C:"%ConEmuDrive%\Programs\Cygwin\Cygwin.ico"
to this:
set HOME= & set CHERE_INVOKING=1 &
%ConEmuDrive%\Programs\Cygwin\bin\bash.exe --login -i
-new_console:C:"%ConEmuDrive%\Programs\Cygwin\Cygwin.ico"
Then it would work correctly.
It works as explained from cygwin:
Create a file ".profile" in your windows home dir. This will load every time when you start cygwin.
You can edit the file with your alias or you can source the .bashrc.
If you'll source, insert "source .bashrc" and save .bashrc also in your windows home dir.
Now you can start editing the .bashrc.
This is working for me On windows 10 with Cygwin64. Don't worry "kubectl" is just the program that I want to run when I type "k". restart Cygwin terminal after the change.
Smith#NB-Smith-3 ~ echo "alias k=C:/Users/Smith/kube/kubectl" >> $HOME/.bash_profile
changes this file
C:\cygwin64\home\Smith.bash_profile
I had same problem is why the path not is correct, the path correct is: D:\C++\cygwin\home\USER_WINDOWS.bash_profile

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