In cmd, it is possible to use Linux commands with the ubuntu or bash commands, but they are very fickle. In batch, it is also possible to make a VBScript-batch hybrid, which got me thinking, is it possible to make a Bash-batch hybrid? Besides being a tongue-twister, I feel that Bash-batch scripts may be really useful.
What I have tried so far
So far I tried using the empty bash and ubuntu commands alone since they switch the normal command-prompt to the Ubuntu/Bash shell, but even if you put commands after the ubuntu/bash they wouldn't show or do anything.
After I tried that, I tried using the ubuntu -run command, but like I said earlier, it’s really fickle and inconsistent on what things work and what things don't. It is less inconsistent when you pipe things into it, but it still usually doesn't work.
I looked here since it seemed like it would answer my question and I tried it, but it didn't work since it required another program (I think).
I also looked to this and I guess it failed miserably, but interesting concept.
What I've gotten from all of my research is that most people think when this is mentioned of a file that could be run either as a .bat file or as .sh shell file instead of my goal, to make a file that runs both batch and Bash commands in the same instance.
What I want this for relates to my other question where I am trying to hash a string instead of a file in cmd, and you could do it with a Bash command, but I would still like to keep the file as a batch file.
Sure you can use Bash in batch, assuming it is available. Just use the command bash -c 'cmd', where cmd is the command that you want to run in Bash.
The following batch line pipes the Hello to cat -A command that prints it including the invisible symbols:
echo Hello | bash -c "cat -A"
Compare the output with the result of the version completely written in Bash:
bash -c "echo Hello | cat -A"
They will slightly differ!
Related
I would like to run a Bash shell script (.sh) using the Windows Subsystem for Linux as part of a Build Event in Visual Studio, in a C++ project.
But there are lots of errors when I do this, and I can't seem to find the right combination of quotation marks and apostrophes and backslashes to either make Bash run in the first place, or to properly pass the path to the script.
How do I make Visual Studio run my Bash shell script as a build event?
(Feel free to skip to the bottom of this answer if you don't care about how to solve the problem and just want a command you can copy and paste!)
Overview
I run a number of Bash shell scripts as part of Build events in Visual Studio, and I used to use Cygwin to run them. Now that the Windows Subsystem for Linux is available, I spent some time switching my builds over to use WSL, and it wasn't as easy as I'd hoped, but it can work, with a little time and energy.
There are several issues you'll run into if you're going to do this:
The path to bash.exe may not be what you think it is, because under the hood, Visual Studio uses a 32-bit build process, so if you're on a 64-bit machine, you can't simply run the 64-bit bash.exe without getting the dreaded 'C:\Windows\System32\bash.exe' is not recognized error.
The path to your solution or project is a Windows path that uses backslashes (\), and those don't play nice in Unix, which prefers forward slashes (/) as a path delimiter.
The root drive of the solution, typically something like C:\, is meaningless gibberish in Unix; to reach the root drive in WSL, you'll need to use a mounted drive under /mnt.
The casing of the drive letter is different between Windows and WSL: In Windows, it's uppercase C:\, and in WSL, it's lowercase /mnt/c.
And to make it a little harder, we don't want to hard-code any of the paths: It should all Just Work, no matter where the solution is found.
The good news is that they're all solvable issues! Let's tackle them one at a time.
Fixing the Issues
1. The proper path to Bash
Per the answer given here, you'll need to use a magic path to reach Bash when running it from a Visual Studio build. The correct path is not C:\Windows\System32\bash.exe, but is actually
%windir%\sysnative\bash.exe
The magic sysnative folder avoids the invisible filesystem redirection performed by the WOW64 layer, and points to the native bash.exe file.
2. Fixing the backslashes
The next problem you're likely to run into is the backslashes. Ideally, you'd like to run a project script like $(ProjectDir)myscript.sh, but that expands to something like C:\Code\MySolution\MyProject\myscript.sh. At a minimum, you'd like that to be at least C:/Code/MySolution/MyProject/myscript.sh, which isn't exactly right, but which is a lot closer to correct.
So sed to the rescue! sed is a Unix tool that mutates text in files: It searches for text using regular expressions, and, among other things, can replace that text with a modified version. Here, we're going to pipe the path we have into sed, and then use some regex magic to swap the path separators, like this (with lines wrapped here for readability):
%windir%\sysnative\bash.exe -c "echo '$(ProjectDir)myscript.sh'
| sed -e 's/\\\\/\//g;'"
If you include this as your build event, you'll see that it now doesn't run the script, but it at least prints something like C:/Code/MySolution/MyProject/myscript.sh to the output console, which is a step in the right direction.
And yes, that's a lot of backslashes and quotes and apostrophes to get the escaping right, because Nmake.exe and bash and sed are all going to consume some of those special symbols while processing their respective command-lines.
3. Fixing the C:\ root path
We want to mutate the sed script so that it turns the C:\ into /mnt/C. A little more regex substitution magic can do that. (And we have to turn on the -r flag in sed so that we can easily use capture groups.)
%windir%\sysnative\bash.exe -c "echo '$(ProjectDir)myscript.sh'
| sed -re 's/\\\\/\//g; s/([A-Z]):/\/mnt\/\1/i;'"
If you run this, you'll now see the output path as something like /mnt/C/Code/MySolution/MyProject/myscript.sh, which is almost but not quite correct.
4. Fixing the case-change in the root path
WSL mounts your disks in lowercase, and Windows mounts them in uppercase. Consistency! How do we fix this? Yet more sed magic!
The \L command can be used to tell sed to transform succeeding characters to lowercase (and there's an equivalent \U for uppercase). The \E command will switch output back to "normal" mode, where characters are left untouched.
Adding these in finally results in the correct path being output:
%windir%\sysnative\bash.exe -c "echo '$(ProjectDir)myscript.sh'
| sed -re 's/\\\\/\//g; s/([A-Z]):/\/mnt\/\L\1\E/i;'"
5. Running it
This whole time, Bash has just been printing out the path to the script. How do we run it instead, now that it's the correct path?
The answer is to add `backticks`! Backticks cause Bash to execute the command contained within them, and to then use that command's output as the arguments to the next command. In this case, we're not going to output anything: We just want to run the output of sed as a command.
So including the backticks, here's the result:
%windir%\sysnative\bash.exe -c "`echo '$(ProjectDir)myscript.sh'
| sed -re 's/\\\\/\//g; s/([A-Z]):/\/mnt\/\L\1\E/i;'`"
The Complete Solution
Here's what the whole solution looks like, for running a script named myscript.sh as a Build Event, in the current Project directory of the current Solution:
%windir%\sysnative\bash.exe -c "`echo '$(ProjectDir)myscript.sh' | sed -re 's/\\\\/\//g; s/([A-Z]):/\/mnt\/\L\1\E/i;'`"
Here's a screen-shot showing the same thing in Visual Studio 2017, for a real C++ project:
It's not easy, but it's not impossible.
If you have Git for Windows installed, try this. I found it simpler than installing WSL. The basic idea is to create an intermediate batch script to call your bash script, using Git bash's in-built bash or sh command from the batch script.
With Git for Windows, you'll have a Git\bin folder e.g. at:
C:\Program Files\Git\bin
Inside that directory you should see the bash.exe and sh.exe programs. So if you add that directory to your Windows Path environment variable then you'll be able to use sh and bash from the Windows command line. These commands will allow you to run your bash scripts "inline" within a CMD console window. That is, they won't spawn a new bash window; meaning the console output will be visible in your VS build.
From there, just create a .bat file which calls your .sh file using either the sh command or the bash command. Not sure the difference; we just use the sh command. So if your bash script is pre.sh, then your batch file would be just a single line calling the bash script:
sh %~dp0\pre.sh
if errorlevel 1 (
exit /b %errorlevel%
)
The %~dp0 assumes the batch and bash scripts are in the same directory. You then point your VS build event to the .bat file. The check for error level is necessary so that any failures from the bash script are forwarded up to the batch script. See: How do I get the application exit code from a Windows command line?.
To hook this in as a build event in VS2019 then, just follow the standard instructions for hooking in a .bat file: https://learn.microsoft.com/en-us/visualstudio/ide/specifying-custom-build-events-in-visual-studio?view=vs-2019.
Update: Beware Visual Studio's (VS's) Path Variable Behaviour
One thing we found quite frustrating with this solution was the tendency of VS to not load in the path variable correctly. It seems to prefer the user variable over the system variable. But even after we deleted the user variable, sometimes the path didn't seem to be getting picked up by VS, and we kept getting "sh is not recognised..." messages on our build console. Whenever that happened, restarting VS seemed to do the trick. Not very satisfying, but it gets us by.
Update: This is not a Full Unix Solution
Git for Windows does have a lot of Unix commands available, but not all of them. So in general, this won't work. For the general case, WSL is more robust. However, if it's just pretty lightweight Unix you need, this will suffice, and will likely be an easier approach for Windows users who would rather avoid the steeper setup cost of installing the full WSL.
Original idea to use Git bash came from here: https://superuser.com/questions/1218943/windows-command-prompt-capture-output-of-bash-script-in-one-step
Instead of backticks, you can wrap command with $( and )
I have a bash script that executes a series of commands, some involving redirection. See cyrus-mark-ham-spam.
I want the script to have a test mode, where all the commands run are printed instead of executing them. As you can see, I have tried to do that by just putting "echo" on the front of each command in test mode.
Unfortunately this doesn't deal with redirection - any redirections are still done, so the program leaves lots of temp files littered about the place when run in test mode.
I have tried various ways to get round this, like quoting the whole command and passing it to a function that either prints it or runs it, but either the redirections work in test mode, or they don't work in run mode.
I thought this must have come up before, and wonder if there is a known solution which does not involve every command being repeated with an if TEST round the pair?
Please note, this is NOT a duplicate of show commands without executing them because neither that question, nor its answers, covers redirection (which is the essence of this question).
I see that it is not a duplicate but there is not general solution to this. You need to look at each command separately.
As long as the command doesn't use arguments enclosed in spaces, like
cmd -a -b -c > filename
, you can quote it:
echo 'cmd -a -b -c > filename'
But real life code is more complex, sure.
I want to send commands in the ADB shell itself as if i had done the following in cmd.
>adb shell
shell#:/ <command>
I am using python 3.4 on a windows 7 OS 64bit machine. I can send one-line shell commands simply using subprocess.getoutput such as:
subprocess.getoutput ('adb pull /storage/sdcard0/file.txt')
as long as the adb commands themselves are recognized by ADB specifically, such as pull and push, however there are other commands such as grep that need to be run IN the shell, like above, since they are not recognized by adb. for example, the following line will not work:
subprocess.getoutput ('adb shell ls -l | grep ...')
To enter the commands in the shell I thought I needed some kind of expect library as that is what 'everyone' suggests, however pexpect, wexpect, and winexpect all failed to work. they were written for python 2 and after being ported to python 3 and my going through the .py files by hand, even those tweaked for windows, nothing was working - each of them for different reasons.
how can i send the input i want to the adb shell directly?
If none of the already recommended shortcuts work for you you can still go the 'regular' way using 'subprocess.Popen' for entering commands in the adb shell with Popen:
cmd1 = 'adb shell'
cmd2 = 'ls -l | grep ...'
p = subprocess.Popen(cmd1.split(), stdin=PIPE)
time.sleep(1)
p.stdin.write(cmd2.encode('utf-8'))
p.stdin.write('\n'.encode('utf-8'))
p.stdin.flush()
time.sleep(3)
p.kill()
Some things to remember:
even though you import subprocess you still need to invoke subprocess.Popen
sending cmd1 as a string or as items in a list should work too but '.split()' does the trick and is easier on the eyes
since you only specidfied you want to enter input to the shell you only need stdin=PIPE. stdout would only be necessary if you wanted to receive output from the shell
time.sleep(1) isn't really necessary, however since many complained about input issues being faster or slower in python 2 vs 3 consider maybe using it. 'they' might have been using versions of 'expect' that need the shell's reply first. this code also worked when i tested it with simply swapping out and in the process with time.sleep(0)
stdin.write will return an error if the input is not encoded properly. python's default is unicode. entering by binary did not work for me in my tests like this "b\ls ..." but .encode() worked. dont forget the endline!
if you use .encode() there is a worry that the line might not get sent properly, so to be sure it might be good to include a flush().
time.sleep(3) is completely uneccesary, but if your command takes a long time to execute (eg a regressive search through the entire device piped out to a txt file on the memory card) maybe give it some extra time before killing anyhting.
remember to kill. if you didnt kill it, the pipe may remain open, and even after exiting the test app on the console the next commend still went to the shell even though the prompt appearsed to be my regular cmd prompt.
Amichai, I have to start with pointing out that your own "solution" is pretty awful. And your explanation makes it even worse. Doing all those unnecessary things just because you do not understand how shell (here I mean your PC's OS shell, not adb) command parsing works.
When all you needed was just this one command:
subprocess.check_output(['adb', 'shell', 'ls /storage/sdcard0 | grep ...']).decode('utf-8')
I have a feeling there's already and answer to this but I wasn't able to find it.
How can I execute each line of output in bash as it comes out?
For example, as my script runs, it generates,
command-1
command-2
command-3
etc.
I need some way to pipe them or something into something that will run them neatly. I've been experimenting with xargs but haven't found anything good to put on the receiving end.
I'd like to avoid doing something like dumping them into a separate script on the side if possible. (I also tried for loops, but they ended up breaking on words instead of lines.)
$ bash echosomecommands.sh | bash
The general idea is pretty simple, I want to make a script for a certain task, I do it in the shell (any shell), and then I want to copy the commands I have used.
If I copy all the stuff in the window, then I have a lot of stuff to delete and to correct. (and is not easy to copy from shell)
Resume: I want to take all the things I wrote...
Is there an easy way to do this easy task?
Update: Partial solution
In bash, the solution is pretty simple, there is a history command, and there are ports of the idea:
IRB: Tweaking IRB
Cmd: Use PowerShell -> Get-History (or use cygwin)
Another Update:
I found that doskey have a parameter history to do this:
cmd: Doskey /history >> history.cmd
Yes, you can use:
history -w filename.sh
This will save your command history to filename.sh. You may need to edit that to keep just the lines at the end that are part of your command sequence.
NOTE: This is a bash command and will not work with all shells.
script may help here. Typing script will throw you into a new shell and save
all input and output to a file called typescript. When you're done with your interaction,
exit the shell. The file typescript is then amenable to grep'ing. For example, you might
grep for your prompt and save the output to the file. If you're a clumsy typist like me, then you may need to do some cleanup work to remove backspaces. There used to be a program that did thisbut I don't seem to find it right now. Here is one I found on the
'net: http://www.cat.pdx.edu/tutors/files/fixts.cpp
This approach is especially useful if you want to track and post on the web an entire interactive session.