I've incurred a worrisome issue with my bash shell. I was editing my bash_profile and accidentally exported an incomplete command (export PATH=/usr/local/bin). After I had reloaded my terminal, nearly all of my bash commands fail to work properly. When I try to run any one of them, the errors state: command not found.
How do I fix this? Is there an alternate way to open or find my bash_profile?
I would appreciate any immediate input I can get on this issue. Thank you in advance.
You can execute commands if you can give the directory name. Almost all the basic Unix commands are under the /bin or /usr/bin directory. For example, /bin/mv.
Fortunately, builtin commands are still recognizable.
Move your .bash_profile and .bashrc file out of the way for now, and see what the system default is.
You can manually edit your PATH on the command line to:
$ PATH="/bin:/usr/bin"
$ cd
$ mv .bash_profile .bash_profile.bak
$ mv .bashrc .bashrc.bak
$ mv .profile .profile.bak
$ mv .bash_login .bash_login.bak
NOTE: Some of these mv command may fail simply because that particular file may not exist.
which will give you access to most of the basic Unix commands. Or you can specify the commands with their full directory names:
$ PATH="/bin:/usr/bin"
$ cd
$ /bin/mv .bash_profile .bash_profile.bak
$ /bin/mv .bashrc .bashrc.bak
$ /bin/mv .profile .profile.bak
$ /bin/mv .bash_login .bash_login.bak
Now, log in again and see what your default $PATH is set to. This is set by the /etc/profile. You might find that's just fine, and remove setting PATH in your startup script.
The standard for PATH is something like this:
/usr/share/bin or /usr/local/bin - These contain non-standard Unix/Linux commands. For example, if you install Maven on your system, the mvn command will usually be located in one of these directories (maybe as a symbolic link). This directory is a place where commands not found in the /bin and /usr/bin directory are stored. This directory is first, so you can replace the version which came with your system with more recent versions. For example, I might have VIM 6.4 installed, but I want to use version 7.3 instead.
/bin:/usr/bin - The standard directories where 99% of the Unix commands live.
$HOME/bin - These are executables you wrote -- either scripts or binaries. This is at the end of the PATH list because it makes sure that you don't accidentally execute the wrong version of the command. Imagine if some joker wrote a shell script called cp that executed /bin/rm instead and placed it in your $HOME/bin directory.
Other directories you'll see may include /sbin/ and /usr/sbin which are administrator commands (ping and ifconfig are sometimes in one of these directories.) /opt/bin/X11 (or wherever the X11 binaries are stored). Sometimes other commands will futz around with your PATH, for example Perlbrew.
#fedorqui's comment provides a quick fix.
The OP could also have used the following to quickly get to a shell with default values for $PATH:
To create a bash shell with a pristine default environment:
without running profile/initialization scripts
without inheriting any environment variables from the current shell
run:
/usr/bin/env -i bash --norc
Note:
Due to use of env's -i option, many environment variables that are normally set will NOT be set in the resulting shell , such as USER, HOME and LANG.
Similarly, the $PATH value you'll get is presumably one hard-coded into bash itself, but it should provide access to at least the standard utilities.
--norc suppresses loading of ~/.bashrc, which normally happens by default for interactive non-login bash shells (bash also supports the --noprofile option to suppress loading of /etc/profile and ~/.bash_profile, but it doesn't apply here, since the shell created is a non-login shell).
If env is in the current shell's $PATH, env -i bash --norc will do.
env is in /usr/bin/ on at least Linux and on FreeBSD/OSX, probably also on other platforms.
Related
I have a Red Hat Linux machine where I am not root.
In my home folder, I added this to my .bash_profile and .bashrc:
export PATH=/path/to/my/directory:$PATH
Then, I ran ./.bash_profile and ./.bashrc.
However, $PATH is not updated.
Any idea why this happens?
When you run these files -- like when you conventionally execute any script -- they're executed in a separate shell, and changes to that shell's state (working directory, variables, etc) are lost when that shell exits. If the goal is to change the state of the interactive shell that you're operating in, you need to source them instead.
Syntax is as follows:
source .bashrc # on extended shells such as bash only
. .bashrc # or on any POSIX-compliant shell
The space is critical; ./.bashrc would instead be trying to run .bashrc as an executable, with its own interpreter, whereas . .bashrc is using the . command documented at http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_18 to execute the contents of the file in your current interpreter.
You need to source your .bash_profile to get the changes in your current shell.
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.
I am attempting to write a bash command line tool that is usable immediately after installation, i.e. in the same shell as its installation script was called. Lets say install-script.sh (designed for Ubuntu) looks like:
# Get the script's absolute path:
pushd `dirname $0` > /dev/null
SCRIPTPATH=`pwd`
popd > /dev/null
# Add lines to bash.bashrc to export the environment variable:
echo "SCRIPT_HOME=${SCRIPTPATH}" >> /etc/bash.bashrc
echo "export SCRIPT_HOME" >> /etc/bash.bashrc
# Create a new command:
cp ${SCRIPTPATH}/newcomm /usr/bin
chmod a+x /usr/bin/newcomm
The idea is that the new command newcomm uses the SCRIPT_HOME environment variable to reference the main script - which is also in SCRIPTPATH:
exec "${SCRIPT_HOME}/main-script.sh"
Now, the updated bash.bashrc hasn't been loaded into the parent shell yet. Worse, I cannot source it from within the script - which is running in a child shell. Using export to change SCRIPT_HOME in the parent shell would at best be duct-taping the issue, but even this is impossible. Also note that the installation script needs to be run using sudo so it cannot be called from the parent shell using source.
It should be possible since package managers like apt do it. Is there a robust way to patch up my approach? How is this usually done, and is there a good guide to writing bash installers?
You can't. Neither can apt.
A package manager will instead just write required data/variables to a file, which are read either by the program itself, by a patch to the program, or by a wrapper.
Good examples can be found in /etc/default/*. These are files with variable definitions, and some even helpfully describe where they're sourced from:
$ cat /etc/default/ssh
# Default settings for openssh-server. This file is sourced by /bin/sh from
# /etc/init.d/ssh.
# Options to pass to sshd
SSHD_OPTS=
You'll notice that none of the options are set in your current shell after installing a package, since programs get them straight from the files in one way or another.
The only way to modify the current shell is to source a script. That's unavoidable, so start there. Write a script that is sourced. That script will in turn call your current script.
Your current script will need to communicate with the sourced one to tell it what to change. A common way is to echo variable assignments that can be directly executed by the caller. For instance:
printf 'export SCRIPT_HOME=%q\n' "$SCRIPTPATH"
Using printf with %q ensures any special characters will be escaped properly.
Then have the sourced script eval the inner script.
eval "$(sudo install-script.sh)"
If you want to hide the sourceing of the top script you could hide it behind an alias or shell function.
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
I've been editing .bashrc files and other init files, and it seems that I've left behind a few code snippets or two that are causing a few errors at the prompt (e.g. file missing), but I can't find them.
How do I debug the prompt to find out what init scripts I've carelessly hacked?
Most of the shells have debug flags that show the commands being executed. Bash may even have one that shows a command before expansion of variables and after. Have you tried checking (I believe) -c -x or -X flags and see if they show the information you are looking for.
You can set them as first thing in the rc files (most global one) or just pass it down into bash command by invoking it from another shell.
In fact, if you invoke bash from another shell, you can also use script command to record everything you see and do into the file, which makes postmortem analysis so much easier.
Try invoking bash with the -x flag, then sourcing your .bashrc or .bash_profile or whatever you're using. That ought to be prolix enough to find your problem
ie:
bash -x
source .bashrc
The easiest way to get a clean initial state is to SSH into your current host, but instead of letting SSH launch your shell with default settings, you provide an explicit command which prevents .bashrc from being read.
ssh -tt localhost /bin/bash --norc
The -tt forces SSH to allocate a TTY, which is what would normally happen when you open a shell connection, but is not default when running an explicit command.
The --norc prevents bash from reading your settings file (since we want to do that ourselves).
You should now be at a bash prompt, in a clean environment. This is useful for examining what variable are set to before your .bashrc runs etc. Enable tracing and source your .bashrc:
set -x # Enable tracing
source .bashrc
Try to see where you've defined prompt - probably it in some dot file in your home directory:
grep PS1 ~/.*
You can see current value of prompt by just printing it:
echo $PS1
HTH
Check the .bash_history file in your home directory to find out what commands you have been running. If you used commands like vi filename to open the init scripts, it will find them in the command history.