Spawn shell and source in one command - zsh

I have sciprt that launches my development environment with multiple tmux tiles. I want to spawn a shell that sources my environment so I dont have to source it myself.
I usually do the following each time I open the tmux tile:
source env/bin/activate
I spawn my shell with $SHELL, I use zsh. I see that bash has the --init-file flag which sources a file, this also does not load the bashrc. I guess thats close but not good enough.
I am looking for something like this $SHELL --source ~/env/bin/activate. Or any workarounds also help

I don't think this is possible; Your best bet is to implement a workaround in your own .zshenv file, e.g.,
if [[ test -e "$MY_INIT_SCRIPT_675" ]] ; then
source "$MY_INIT_SCRIPT_675"
fi

Related

WSL PATH environment variable is incorrect / zsh config not loaded [duplicate]

I am using Ubuntu via WSL 2.0 on Windows 10 and would like to run Texlive from the Windows command line. To do so I prepended the Texlive folder to the path in /etc/environment (I also tried a number of other locations eg. $HOME/.bashrc):
C:\Users\scott\Documents>wsl echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/mnt/c/Windows/system32:...
C:\Users\scott\Documents>wsl
scott#SCOTT-PC:/mnt/c/Users/scott/Documents$ echo $PATH
/usr/local/texlive/2020/bin/x86_64-linux:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/mnt/c/Windows/system32:...
Why is there a difference between these two paths? Is it possible to change the first PATH variable?
To be honest, when I first looked at this question, I thought it would be an easy answer. Oh how wrong I was. There are a lot of nuances to how this works.
Let's start with the fairly "easy" part, though. The main difference between the first method and the second:
wsl by itself launches into a login (and interactive) shell
the shell launched with wsl echo $PATH is neither a login shell nor an interactive shell
So the first will source both login scripts (e.g. ~/.profile) and interactive startup scripts (e.g. ~/.bashrc). The second form does not get to source either of these.
You can see this a different way (and get to the solution) with the following commands:
wsl -e bash -c 'echo $PATH'
wsl -e bash -li -c 'echo $PATH'
The -li forces bash to run as a login and interactive shell, thus sourcing all of the applicable startup scripts. And, as #bovquier points out in the comments, a single quote is needed here to prevent PowerShell from interpolating the $ before it gets to Bash. That, or escape it.
You should be able to run TeX Live the same way, just replacing the "echo $PATH" with the startup command you need for TeX Live.
A second option would be to create a script that both adds the path and runs the command, and just launch that script through wsl /path/to/script.sh
That said, I honestly don't think that your current login/interactive PATH is coming from /etc/environment. In my testing, at least, /etc/environment has no use in WSL, and that's to be expected. /etc/environment is only sourced by PAM modules, and with no login check performed by WSL, there's no reason to invoke PAM in either the wsl nor the wsl echo $PATH commands.
I'd expect that you still have the PATH setting in ~/.bashrc or somewhere similar), and that's where the shell is picking it up from at the moment.
While this isn't necessarily critical to understanding the answer, you might also wonder, if /etc/environment isn't used for setting the default (non-login, non-interactive) path in WSL, what is? The answer seems to be that it is hard-coded into the init that starts up WSL. That init is also what appends the Windows path (assuming you don't have that feature disabled in /etc/wsl.conf).

Use cmd commands in QT

Hi i was checking and anyone can use commands very similar in cmd like dir mkdir etc.
But for example when i try to use command (cd ..) i couldn't
QProcess consola;
consola.start("cmd.exe /C " + comando);
consola.waitForFinished();
consola.waitForReadyRead();
This is the question how i can use more commands in cmd for qt for example.
At least from the command line:
cmd /C "cd \"
works as did directories other than root. (Note the parenthesis around the command since it contains embedded spaces.) However, this example isn't very useful because this executes the command shell, changes the directory in that command shell, and then the command shell disappears, and your current directory is back to where you started.
I recommend looking into the QDir class, which has methods such as "current ()" and "setCurrent ()" for getting and setting the current directory. There are equivalents for mkdir and many others. Also, using QDir is much more cross-platform friendly, where using the "cmd" shell is Windows-specific.
You don't say what you're trying to accomplish, so beyond that suggestion, it's impossible to know how to best help you.
Your process's current directory can be and mostly is different than current directory of your is running. Please read chdir manpage for that.
That command is mostly working but changing the current directory of your process.

How to kill a tmux pane along with the process running on it?

Let's say you run a command like grunt serve on a tmux pane,
and you kill the pane on which the command is running. I found that
the process is not killed:
ps aux | grep grunt
still shows that grunt is running even though the pane is gone.
How do you kill a tmux pane along with the process(es)?
To stop the program running you can close the pane by entering <C-B> x and then entering y.
Just do: <CTRL-B>:kill-pane
Use Ctrl + b¹, > to get a menu with this and other useful commands:
This is what uses the Spotify plugin.
¹ Or the chosen tmux escape sequence.
Other notes and sources
tmux list-keys | grep display-menu #
curl cht.sh/tmux # Online cheatsheet
https://wiki.archlinux.org/title/tmux
You may find the tmux-safekill plugin useful.
I wanted it to kill Ruby processes, so I had to fork the repo to add that functionality in, so I'm sure you could do the same for grunt processes if you don't get all the functionality you need from the repo directly.

Command line app: Unix cd command

My Mac OS command line application is making Unix calls such as:
system("rm -rf /Users/stu/Developer/file);
perfectly successfully.
So why is the following not changing the current directory?
system("cd /Users/me/whatever");
system("pwd"); //cd has not changed
Because
system() executes a command specified in command by calling /bin/sh -c command, and returns after the command has been completed.
So each command is executed independently, each in a new instance of the shell.
So your first call spawns a new sh (with your current working directory), changes directories, and then exits. Then the second call spawns a new sh (again in your CWD).
See the man page for system().
The better solution is to not use system. It has some inherent flaws that can leave you open to security vulnerabilities. Instead of executing system() commands, you should use the equivalent POSIX C functions. Everything that you can do from the command-line, you can do with C functions (how do you think those utilities work?)
Instead of system("rm -rf ...") use this.
Instead of system("cd ...") use chdir().
Instead of system("pwd ...") use getcwd().
There are some differences, of course, but these are the fundamental equivalents of what you're trying to do.

"exec source <script>" does not work in tcl

I'm trying to call a script in Tcl with the command:
exec source <script path>
and I get the error
couldn't execute "source": no such file or directory
How can I call another script from tcl?
Edit: I am running a command I got from another person in my office. I was instructed to run "source " explicitly with source. So in other words, how would I run any command that would work in cshell, in Tcl?
If the script you were given is a cshell script, you can exec it like this:
exec /bin/csh $path_to_script
In effect, this is what the 'source' command does from within an interactive shell. It's not clear whether this is really what you want to do or not (not exactly, but close enough for this discussion).
The reason you can't exec the source command is that exec will only work on executable files (hence the name 'exec'). The source command isn't implemented as an exectuable file, it is a command built-in to the shell. Thus, it can't be exec'd.
If you really feel the need to exec the source command or any other built-in command you can do something like this:
exec /bin/csh -c "source $path_to_script"
In the above example you are execing the c shell, and asking it to run the command "source ". For the specific case of the source command, this doesn't really make much sense.
However, I'm not sure any of this will really do what you expect. Usually if someone says "here's some commands, just do 'source ', it usually just defines some aliases and whatnot to be used from within an interactive shell. Those aliases won't work from within Tcl.
source in csh, like . in bash, executes a script without spawning a new process.
The effect is that any variable that is set in that script is available in current csh session.
Actually, source is a built-in command of csh, thus not available from tcl exec, and using exec without source would not give the specific source effect.
There is no simple way to solve your problem.
source load the source file
you should do:
source <script path>
If you want to execute it, then you need to call the main proc.
another option would be to do:
exec [info nameofexecutable] <scritp path>
Some confusion here. exec runs a separate program, possibly with arguments.
source is not a separate program, it is another Tcl command which reads a file of Tcl commands and executes them, but does not pass arguments. If the other script you are trying to call is written to be run on from the command line, it will expect to find its arguments as a list in variable argv. You can fake this by setting argv to the list of arguments before running source, eg.
set argv {first_arg second_arg}
source script_path
Alternatively you could use exec to start a whole separate Tcl executable and pass it the script and arguments:
exec script_path first_arg second_arg
the error speaks for itself. Make sure you give the correct path name, specify full path if necessary. and make sure there is indeed the file exists in that directory
Recently I wanted to set some UNIX environment variables by sourcing a shell script and stumbled across the same problem. I found this simple solution that works perfectly for me:
Just use a little 3-line wrapper script that executes the source command in a UNIX shell before your Tcl script is started.
Example:
#!/bin/csh
source SetMyEnvironment.csh
tclsh MyScript.tcl

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