This might be a naive question, but I'm really not sure how to do it. I submit a spark job and I get the following output.
Run job succeeded. Submission id: driver-20170824224209-0001
I want to programmatically query the status of this job. How can I use the output in the console to extract the id to a variable using a bash script.
Any help appreciated.
Let's say you command is cmd and you want to store the output of the command in ( say ) a variable called res, one way in bash is to run the command in single quotes
res=`cmd`
or embed the command within $()
res=$(cmd)
Capture both stdout and stderr in Bash
Related
I have rather complex bash script which is normally run manually and thus needs live output on the console (stdout and stderr).
However, since the outcome and output of this script is rather important I'd like to save its output at the end into a database.
I have already a trap function for this and the database query as such is also not a problem. The problem is: How do I get the output of the entire script till that point into a variable?
The live console output should be preserved. The output after the database query (if any) does not matter.
Is this possible at all? Might it be necessary to wrap the script into another script (file)?
I'm doing similar task like this
exec 5>&1
message=$(check|tee /dev/fd/5)
mutt -s "$subjct" "$mailto" <<< "$message"
Add your script instead of check function and change mailing to db query.
I have a shell script that is using echo to give a continuous output (the progress of an rsync) that I am using AppleScript to run with administrator privileges. Before I was using NSTask to run the shell script, but I couldn't find a way to run it with the privileges that it needed, so now I am using applescript to run it. When it was running via NSTask, I could use an output pipe and waitForDataInbackgroundAndNotify to get the continuous output and put it into a text field, but now that I am using AppleScript, I cannot seem to find a way to accomplish this. The shell script is still using echo, but it seems to get lost in the AppleScript "wrapper." How do I make sure that the AppleScript sees the output from the shell script and passes it on to the application? Remember, this isn't one single output, but continuous output.
Zero is correct. When you use do shell script, you can consider it similar to using backticks in perl. The command will be executed, and the everything sent to STDOUT will be returned as the result.
The only work around would be to have the your command write the output to a temporary file and then use do shell script "foo" without waiting. From there, you can read from the file sequentially using native AppleScript commands. It's clunky, but it'll work in a pinch.
What I would like to do is:
run a ruby script...
that executes a shell command
and redirects it to a named pipe accessible outside the script
from the system shell, read from that pipe
That is, have the Ruby script capture some command output and redirect it in such a way that it's connectable to from outside the script?
I want to mention that the script cannot simply start and exit, since it's a REPL. The idea is that using the REPL you would be able to run a command and redirect its output elsewhere to consume it.
Using abort and an exit message, will pass the message to STDERR (and the script will fail with exit code 1). You can pass this shell command output in this way.
This is possibly not the only (or best) way, but it has worked for me in the past.
[edit]
You can also redirect the output to a file (using standard methods), and read that file outside the ruby script.
require 'open3'
stdin, stderr, status = Open3.capture3(commandline)
stdin.chomp #Here, you should ge
Incase, if someone wanted to use you can get the output via stdin.chomp
I am designing a ruby program that needs to run a command and store it a variable.
var = exec('some command');
This doesn't work the way I want it to, it just prints the output from the command prompt and then ends the program.
So is there a function that doesn't end the program, doesn't print the cmd output and stores the information in a variable?
Thanks in advance.
You need to use either Ruby's built in backtick syntax, or use %x
output = `some command`
or
output = %x(some "command")
Open3 grants you access to stdin, stdout, stderr and a thread to wait
the child process when running another program. You can specify
various attributes, redirections, current directory, etc., of the
program as Process.spawn.
See the various ways of executing a command
I'm using a bash script to automatically run a simulation program. This program periodically prints the current status of the simulation in the console, like "Iteration step 42 ended normally".
Is it possible to abort the script, if the console output is something like "warning: parameter xyz outside range of validity"?
And what can I do, if the console output is piped to a text file?
Sorry if this sounds stupid, I'm new to this :-)
Thanks in advance
This isn't an ideal job for Bash. However, you can certainly capture and test STDOUT inside a Bash iteration loop using an admixture of conditionals, grep-like tools, and command substitution.
On the other hand, if Bash isn't doing the looping (e.g. it's just waiting for an external command to finish) then you need to use something like expect. Expect is purpose-built to monitor output streams for regular expressions, and perform branching based on expression matches.