I'm using the post-checkout hook to try and set environment variables when switching branches.
#!/bin/sh
echo "Updating environment variables..."
OLD_IFS=$IFS
IFS=$'\n'
for x in $(cat .env | sed -e '/^#/d;/^\s*$/d' -e "s/'/'\\\''/g" -e "s/=\(.*\)/='\1'/g")
do
var_name=$( cut -d '=' -f 1 <<< "$x" )
export $x
pwsh.exe -c "\$env:$x"
pwsh.exe -c "echo 1; echo \$env:$var_name"
export $x
done
IFS=$OLD_IFS
The problem is that git hook is executed with WSL so the variables I set are lost after the post-hook
I assume this is because of the shebang?
I've tried #!/usr/bin/env pwsh but I get the error Processing -File '.git/hooks/post-checkout' failed because the file does not have a '.ps1' extension. Specify a valid PowerShell script file name, and then try again.
Is this something that can be done? I want to automatically change the DB connection when I switch branches.
As anthony sottlie noted, you can't do it that way.
What you need instead is a command that you run instead of git switch or git checkout. In this command, you will:
run git switch or git checkout, then
set the environment variables you would have set in your script, the way you would have set them
and since this will be done by the command itself, rather than in a subprocess, it will affect further commands run by this same command-line interpreter.
Related
Is there a way to tell a bash script not to import any variables from the parent shell i.e. ignore exported variables. There is such capability in slurm --export=NONE so I wonder if there is an option I can put in the #!/bin/bash line to get similar behavior.
On linux the cleanest option I found was:
#!/usr/bin/env -S - bash
env
which for me prints:
PWD=/home/allan
SHLVL=1
_=/usr/bin/env
Another option is:
#!/usr/bin/env bash
[ -n "$HOME" ] && exec -c "$0"
env
Possible using $BASH_SOURCE[0] instead of $0 as the latter can be set by user. $BASH_SOURCE, however, is not always set. Hard-coding the script path would work but that's ugly.
I'm a Windows user with the Git Bash shell as my daily-driver. I'm curious how the __git_ps1 function updates the prompt every time you change a directory. It's really the only example of updating the bash prompt on the fly that I've seen. I want to leverage this behavior in my own function to add a display on my prompt if I have an RDP session open.
tldr: Any ideas on how the __git_ps1 function evaluates the bash prompt on the fly????
So here is my simple function to see if the RDP client is running
function __rdp_ps1() {
local MATCH=
if tasklist | grep --quiet mstsc; then
MATCH="\e[41mRDP\e[0m"
fi
echo "$MATCH"
}
So the idea is I want to display RDP with a red background, and I want my shell to evaluate this on the fly the same way __git__ps1 is seemingly able to.
What I've investigated (without real success) so far
/etc/profile.d/git-prompt.sh
This block seems to create the PS1 my shell is using
PS1='\[\033]0;$TITLEPREFIX:$PWD\007\]' # set window title
PS1="$PS1"'\n' # new line
PS1="$PS1"'\[\033[32m\]' # change to green
PS1="$PS1"'\u#\h ' # user#host<space>
PS1="$PS1"'\[\033[35m\]' # change to purple
PS1="$PS1"'$MSYSTEM ' # show MSYSTEM
PS1="$PS1"'\[\033[33m\]' # change to brownish yellow
PS1="$PS1"'\w' # current working directory
if test -z "$WINELOADERNOEXEC"
then
GIT_EXEC_PATH="$(git --exec-path 2>/dev/null)"
COMPLETION_PATH="${GIT_EXEC_PATH%/libexec/git-core}"
COMPLETION_PATH="${COMPLETION_PATH%/lib/git-core}"
COMPLETION_PATH="$COMPLETION_PATH/share/git/completion"
if test -f "$COMPLETION_PATH/git-prompt.sh"
then
. "$COMPLETION_PATH/git-completion.bash"
. "$COMPLETION_PATH/git-prompt.sh"
PS1="$PS1"'\[\033[36m\]' # change color to cyan
# tried hamjamming PS1="$PS1 `__rdp_ps1`" here, it only works on login
PS1="$PS1"'`__git_ps1`' # bash function
fi
fi
PS1="$PS1"'\[\033[0m\]' # change color
PS1="$PS1"'\n' # new line
PS1="$PS1"'$ ' # prompt: always $
So I went to see where this file was being sourced to see if that could lead to the answer
/etc/bash.bashrc
Last line held the gold
# Fixup git-bash in non login env
shopt -q login_shell || . /etc/profile.d/git-prompt.sh`
So I evaluated shopt login_shell and it's always on, but I don't really know what that means because the comment leads me to believe that when login env is off, the prompt script will be evaluated
Any ideas???
Your problem might be that you define your $PS1 with double quotes, which bash interprets when executing. Which means that __rdp_ps1 is ran when $PS1 is defined.
In your .bashrc, try replacing the definition with:
PS1='$PS1 `__rdp_ps1`' # Note the single quote.
I have a similar feature on my PS1 (but to display the number of jobs in the background), here is the full version (available here: https://github.com/padawin/dotfiles/blob/master/.bashrc#L70):
function j(){
jobs | wc -l | egrep -v ^0 | sed -r 's/^([0-9]+)/ (\1)/'
}
PROMPT_COMMAND=__prompt_command # Func to gen PS1 after CMDs
__prompt_command() {
local EXIT="$?" # This needs to be first
PS1="$(virtual_env_name)"
local RCol='\[\e[0m\]'
local Red='\e[0;31m'
local Gre='\e[0;32m'
local Blu='\e[1;34m'
PS1+="${Gre}\u#\h$(j)${RCol}: ${Red}\w${Blu}$(__git_ps1)"
if [ $EXIT != 0 ]; then
PS1+="$Red \342\234\226 (${EXIT})"
else
PS1+="$Gre \342\234\224"
fi
PS1+="$RCol\n> "
}
Which can be simplified as the following in .bashrc:
function j(){
jobs | wc -l | egrep -v ^0 | sed -r 's/^([0-9]+)/ (\1)/'
}
PS1='\u$(j) > ' # Note the single quote here
Which behaves as follow:
padawin > vim
[1]+ Stopped vim
padawin (1) > fg
vim
padawin >
Not directly a solution but this might help: if you want to know where the __git_ps1 function lives locally on your filesystem so you can experiment with making edits, you can do
grep -r __git_ps1 /
which searches for the string '__git_ps1' across the file contents of git bash's entire filesystem (where / is actually C:\Program Files\Git or wherever you have it installed).
For me, it was at /mingw64/share/git/completion/git-prompt.sh
My use case was removing the parenthesis from the branch name, which I did by changing this line:
local printf_format=' (%s)'
in the __git_ps1 () function
What you are looking for is PROMPT_COMMAND. Bash will execute whatever is in there before displaying a prompt. If your PS1 is being updated on-the-fly, you probably already have a PROMPT_COMMAND.
I wish to write a shell script to export variables.
Below I have listed the script .
echo "Perform Operation in su mode"
export ARCH=arm
echo "Export ARCH=arm Executed"
export PATH='/home/linux/Practise/linux-devkit/bin/:$PATH';
echo "Export path done"
export CROSS_COMPILE='/home/linux/Practise/linux-devkit/bin/arm-arago-linux-gnueabi-';
echo "Export CROSS_COMPILE done"
But this doesn't seem to work properly. I have to individually execute the commands at the shell prompt instead.
You need to run the script as source or the shorthand .
source ./myscript.sh
or
. ./myscript.sh
This will run within the existing shell, ensuring any variables created or modified by the script will be available after the script completes.
Running the script just using the filename will execute the script in a separate subshell.
Please show us more parts of the script and tell us what commands you had to individually execute and want to simply.
Meanwhile you have to use double quotes not single quote to expand variables:
export PATH="/home/linux/Practise/linux-devkit/bin/:$PATH"
Semicolons at the end of a single command are also unnecessary.
So far:
#!/bin/sh
echo "Perform Operation in su mode"
export ARCH=arm
echo "Export ARCH=arm Executed"
export PATH="/home/linux/Practise/linux-devkit/bin/:$PATH"
echo "Export path done"
export CROSS_COMPILE='/home/linux/Practise/linux-devkit/bin/arm-arago-linux-gnueabi-' ## What's next to -?
echo "Export CROSS_COMPILE done"
# continue your compilation commands here
...
For su you can run it with:
su -c 'sh /path/to/script.sh'
Note: The OP was not explicitly asking for steps on how to create export variables in an interactive shell using a shell script. He only asked his script to be assessed at most. He didn't mention details on how his script would be used. It could have been by using . or source from the interactive shell. It could have been a standalone scipt, or it could have been source'd from another script. Environment variables are not specific to interactive shells. This answer solved his problem.
Run the script as source= to run in debug mode as well.
source= ./myscript.sh
I cannot solve it with source ./myscript.sh. It says the source not found error.
Failed also when using . ./myscript.sh. It gives can't open myscript.sh.
So my option is put it in a text file to be called in the next script.
#!/bin/sh
echo "Perform Operation in su mode"
echo "ARCH=arm" >> environment.txt
echo "Export ARCH=arm Executed"
export PATH="/home/linux/Practise/linux-devkit/bin/:$PATH"
echo "Export path done"
export "CROSS_COMPILE='/home/linux/Practise/linux-devkit/bin/arm-arago-linux-gnueabi-' ## What's next to -?" >> environment.txt
echo "Export CROSS_COMPILE done"
# continue your compilation commands here
...
Tnen call it whenever is needed:
while read -r line; do
line=$(sed -e 's/[[:space:]]*$//' <<<${line})
var=`echo $line | cut -d '=' -f1`; test=$(echo $var)
if [ -z "$(test)" ];then eval export "$line";fi
done <environment.txt
In my case, I gave extra spaces before and after =.
For example, in my shell file(say deploy.sh)
I initially write
GIT_SHA = $(git rev-parse HEAD)
But I fixed it by using:
GIT_SHA=$(git rev-parse HEAD)
So please note that we should not give any spaces before and after the =.
I have a .sh (start_sim.sh) and a .bash (sim_sources.bash) file.
The sim_sources.bash file is called from within the start_sim.sh and should set an environment variable $ROBOT to a certain value. However the ROBOT variable never changes when I call ./start_sim.sh. Is there a fundamental mistake in the way I am trying to do this?
start_sim.sh contains:
#!/bin/bash
echo -n "sourcing sim_sources.bash..."
source /home/.../sim_sources.bash
echo "done."
sim_sources.bash contains:
# set the robot id
export ROBOT=robot
EDIT: Could you also propose a way to work around this issue? I would still need to set variables from with in the .bash file.
EDIT2:
Thanks for your replys!
Finally I ended up solving it with a screen and stuffing commands to it:
echo -n "starting screen..."
screen -dmS "sim_screen"
sleep 2
screen -S "sim_screen" -p 0 -X stuff "source /home/.../sim_sources.bash$(printf \\r)"
sleep 5
screen -S "sim_screen" -p 0 -X stuff "source /home/.../start_sim.sh$(printf \\r)"
You're setting the ROBOT variable in the start_sim.sh script, but that's not available to parent processes (your spawning shell/command-prompt).
Exporting a variable e.g. export ROBOT=robot makes the variable available to the current process and child processes. When you invoke ./start_sim.sh you're invoking a new process.
If you simply source start_sim.sh in your shell, that script runs as part of your shell process and then your variable will be available.
As Brian pointed out the variables are not available outside of the script.
Here a adapted script that shows this point:
#!/bin/bash
echo -n "sourcing sim_sources.bash..."
. sim_sources.bash
echo $ROBOT
echo "done."
The workaround you are asking for is to start a new shell from the actual shell with the environmental values already set:
#!/bin/bash
echo -n "sourcing sim_sources.bash..."
. sim_sources.bash
echo "done."
bash
This results in:
bash-4.1$ printenv | grep ROBOT
ROBOT=robot
I am on Ubuntu 16.04
I used /bin/sh instead of /bin/bash and it works !
This question already has answers here:
Why can't I change directories using "cd" in a script?
(33 answers)
Closed 7 years ago.
What I'm trying to do
I've created a shell script that I've added to my $PATH that will download and get everything setup for a new Laravel project. I would like the script to end by changing my terminal directory into the new project folder.
From what I understand right now currently it's only changing the directory of the sub shell where the script is actually running. I can't seem to figure out how to do this. Any help is appreciated. Thank you!
#! /usr/bin/env bash
echo -e '\033[1;30m=========================================='
## check for a directory
if test -z "$1"; then
echo -e ' \033[0;31m✖ Please provide a directory name'
exit
fi
## check if directory already exist
if [ ! -d $1 ]; then
mkdir $1
else
echo -e ' \033[0;31m✖ The '"$1"' directory already exists'
exit
fi
# move to directory
cd $1
## Download Laravel
echo -e ' \033[0;32m+ \033[0mDownloading Laravel...'
curl -s -L https://github.com/laravel/laravel/zipball/master > laravel.zip
## Unzip, move, and clean up Laravel
echo -e ' \033[0;32m+ \033[0mUnzipping and cleaning up files...'
unzip -q laravel.zip
rm laravel.zip
cd *-laravel-*
mv * ..
cd ..
rm -R *-laravel-*
## Make the /storage directory writable
echo -e ' \033[0;32m+ \033[0mMaking /storage directory writable...'
chmod -R o+w storage
## Download and install the Generators
echo -e ' \033[0;32m+ \033[0mInstalling Generators...'
curl -s -L https://raw.github.com/JeffreyWay/Laravel-Generator/master/generate.php > application/tasks/generate.php
## Update the application key
echo -e ' \033[0;32m+ \033[0mUpdating Application Key...'
MD5=`date +”%N” | md5`
sed -ie 's/YourSecretKeyGoesHere!/'"$MD5"'/' application/config/application.php
rm application/config/application.phpe
## Create .gitignore and initial git if -git is passed
if [ "$2" == "-git" ]; then
echo -e ' \033[0;32m+ \033[0mInitiating git...'
touch .gitignore
curl -s -L https://raw.github.com/gist/4223565/be9f8e85f74a92c95e615ad1649c8d773e908036/.gitignore > .gitignore
# Create a local git repo
git init --quiet
git add * .gitignore
git commit -m 'Initial commit.' --quiet
fi
echo -e '\033[1;30m=========================================='
echo -e ' \033[0;32m✔ Laravel Setup Complete\033[0m'
## Change parent shell directory to new directory
## Currently it's only changing in the sub shell
filepath=`pwd`
cd "$filepath"
You can technically source your script to run it in your parent shell instead of spawning a subshell to run it. This way whatever changes you make to your current shell (including changing directories) persist.
source /path/to/my/script/script
or
. /path/to/my/script/script
But sourcing has its own dangers, use carefully.
(Peripherally related: how to use scripts to change directories)
Use a shell function to front-end your script
setup () {
# first, call your big script.
# (It could be open-coded here but that might be a bit ugly.)
# then finally...
cd someplace
}
Put the shell function in a shell startup file.
Child processes (including shells) cannot change current directory of parent process. Typical solution is using eval in the parent shell. In shell script echo commands you want to run by parent shell:
echo "cd $filepath"
In parent shell, you can kick the shell script with eval:
eval `sh foo.sh`
Note that all standard output will be executed as shell commands. Messages should output to standard error:
echo "Some messages" >&2
command ... >&2
This can't be done. Use exec to open a new shell in the appropriate directory, replacing the script interpreter.
exec bash
I suppose one possibility would be to make sure that the only output of your script is the path name you want to end up in, and then do:
cd `/path/to/my/script`
There's no way your script can directly affect the environment (including it's current directory) of its parent shell, but this would request that the parent shell itself change directories based on the output of the script...