Lua: forward output from Minicom - lua

I have a Lua script and in there I open a minicom session which executes a script (with the -S" parameter).
local myFile = assert(io.popen('minicom -S myScript.sh ' myDevice ' -C myLogFile.log'))
local myFileOutput = myFile:read('*all')
myFile:close()
This works really fine.
But I would like to get the same output as if I execute the minicom command itself:
minicom -S myScript.sh ' myDevice ' -C myLogFile.log
Right now I don't get any output at all (I know that that's somehow obvious).
I would that the output should also occur at (at least nearly) the same time as with the minicom command itself. Not one big chuck of data at the end.
Does anyone know how to achieve that?

If I understand you correctly, you need something like
local myFile = assert(io.popen('minicom ...'))
for line in myFile:lines('l') do
print(line)
end
myFile:close()

Related

Why QProcess is not showing stdout from bash script executed in remote server?

I made an script (findx.h) that doesn't have any problem when i ran it on Solaris server via console (bash-3.2$ ./findx.sh)
The problem appears when i try to run it from a windows Qt app using QProcess (code below) where it doesn't display the ouput of the command.
I tried little variations and appear to show data when just use one pipe instead of two. But i need the two: grep and ggrep.
//findx.h in solaris
//WHAT WORKS
#!/bin/bash
echo pass | sudo -S /usr/sbin/snoop -x0 -ta HSM1000 port 1000
//WHAT I WANT
#!/bin/bash
echo pass | sudo -S /usr/sbin/snoop -x0 -ta HSM1000 port 1000 | /usr/sfw/bin/ggrep -A 2 KR01
//Qt on windows
QString commands="(";
commands +="source setpath.sh";
commands +=";/path/to/script/findx.sh";
commands +=")";
this->logged=false;
QString program = "plink.exe";
QStringList arguments;
arguments <<"-ssh"
<<ip
<<"-l"
<<user
<<"-pw"
<<pass
<<commands;
this->myProcess=new QProcess(this);
connect(this->myProcess,SIGNAL(started()),
this, SLOT(onprocess_started()));
connect(this->myProcess, SIGNAL(errorOccurred(QProcess::ProcessError)),
this, SLOT(onprocess_errorOcurred(QProcess::ProcessError)));
connect(this->myProcess, SIGNAL(finished(int, QProcess::ExitStatus)),
this, SLOT(onprocess_finished(int, QProcess::ExitStatus)));
connect(this->myProcess, SIGNAL(readyReadStandardError()),
this, SLOT(onprocess_readyReadStandardError()));
connect(this->myProcess, SIGNAL(readyReadStandardOutput()),
this, SLOT(onprocess_readyReadStandardOutput()));
connect(this->myProcess, SIGNAL(stateChanged(QProcess::ProcessState)),
this, SLOT(onprocess_stateChanged(QProcess::ProcessState)));
this->myProcess->start(program, arguments);
this->ui->labStatus->setText("Starting");
return 0;
// How i read, i do the same for stderr and put it also in plainOutput
QByteArray err=this->myProcess->readAllStandardOutput();
QString m="Standard output:"+QString(err.data());
this->ui->plainOutput->appendPlainText(m);
please any advice would be useful.
Thanks in advance.

io.popen how to get the go output in lua

How could I capture compiler errors go in lua?
I'm trying to get the output of the comp compiler errors in a tmux panel using lua
when executing the script the result is only shown in the current panel and not in the second panel
and the /tmp/output file is always empty
cmd=io.popen("go build -gcflags=-e scree.go")
f=io.open("/tmp/output")
f:write(cmd:read("*all"))
for line in f:lines() do
os.execute("tmux run-shell -t 2 'echo " .. line .. "' ")
end
f:close()
Is there any way to do this without using a temporary file?
I'm not totally clear on this. But maybe something like the following. i.e. pipe stderr to stdout and capture the result (not tested).
f = assert (io.popen ("go build -gcflags=-e scree.go 2>&1"))
for line in f:lines() do
os.execute("tmux run-shell -t 2 'echo " .. line .. "' ")
end
f:close()
I think the key is that popen won't capture stderr. See further details about that here

error while executing lua script for redis server

I was following this simple tutorial to try out a simple lua script
http://www.redisgreen.net/blog/2013/03/18/intro-to-lua-for-redis-programmers/
I created a simple hello.lua file with these lines
local msg = "Hello, world!"
return msg
And i tried running simple command
EVAL "$(cat /Users/rsingh/Downloads/hello.lua)" 0
And i am getting this error
(error) ERR Error compiling script (new function): user_script:1: unexpected symbol near '$'
I can't find what is wrong here and i haven't been able to find someone who has come across this.
Any help would be deeply appreciated.
Your problem comes from the fact you are executing this command from an interactive Redis session:
$ redis-cli
127.0.0.1:6379> EVAL "$(cat /path/to/hello.lua)" 0
(error) ERR Error compiling script (new function): user_script:1: unexpected symbol near '$'
Within such a session you cannot use common command-line tools like cat et al. (here cat is used as a convenient way to get the content of your script in-place). In other words: you send "$(cat /path/to/hello.lua)" as a plain string to Redis, which is not Lua code (of course), and Redis complains.
To execute this sample you must stay in the shell:
$ redis-cli EVAL "$(cat /path/to/hello.lua)" 0
"Hello, world!"
If you are coming from windows and trying to run a lua script you should use this format:
redis-cli --eval script.lua
Run this from the folder where your script is located and it will load a multi line file and execute it.
On the off chance that anyone's come to this from Windows instead, I found I had to do a lot of juggling to achieve the same effect. I had to do this:
echo “local msg = 'Hello, world!'; return msg” > hello.lua
for /F "delims=" %i in ('type hello.lua') do #set cmd=%i
redis-cli eval "%cmd%" 0
.. if you want it saved as a file, although you'll have to have all the content on one line. If you don’t just roll the content into a set command
set cmd=“local msg = 'Hello, world!'; return msg”
redis-cli eval "%cmd%" 0

Calling Bash Commands With Multiple args From Ruby?

I write this code in my rails project.It's to execute a shell script ,But my shell script can catch #directdown only.
rails script
#cmd = "/downafile.sh #{#directdown} #{#file.id} #{#filename}"
`#{#cmd}`
shell script
echo $1 >> /tmp/ceshi.tmp
echo $2 >> /tmp/ceshi.tmp
echo $3 >> /tmp/ceshi.tmp
Thanks.
`` and system command works in similar manner.
But system method will return true on success.
Try with this:
#cmd = "/downafile.sh '#{#directdown}' '#{#file.id}' '#{#filename}'"
`#{#cmd}`
Try using puts #cmd to see the command generated and see whether the command is what you intended. If it is try executing it from the terminal to test whether your shell script works. I think the parameters #file.id and #filename value may be nil so on interpolation it will be replaced by "". puts their values also to check.
I don't know what is the meaning of `` in Ruby, but I think you can use the system function to invoke an external program. Something like,
#cmd = "/downafile.sh #{#directdown} #{#file.id} #{#filename}"
system(#cmd)
Hope it helps.

unix at command pass variable to shell script?

I'm trying to setup a simple timer that gets started from a Rails Application. This timer should wait out its duration and then start a shell script that will start up ./script/runner and complete the initial request. I need script/runner because I need access to ActiveRecord.
Here's my test lines in Rails
output = `at #{(Time.now + 60).strftime("%H:%M")} < #{Rails.root}/lib/parking_timer.sh STRING_VARIABLE`
return render :text => output
Then my parking_timer.sh looks like this
#!/bin/sh
~/PATH_TO_APP/script/runner -e development ~/PATH_TO_APP/lib/ParkingTimer.rb $1
echo "All Done"
Finally, ParkingTimer.rb reads the passed variable with
ARGV.each do|a|
puts "Argument: #{a}"
end
The problem is that the Unix command "at" doesn't seem to like variables and only wants to deal with filenames. I either get one of two errors depending on how I position "s
If I put quotes around the right hand side like so
... "~/PATH_TO_APP/lib/parking_timer.sh STRING_VARIABLE"
I get,
-bash: ~/PATH_TO_APP/lib/parking_timer.sh STRING_VARIABLE: No such file or directory
I I leave the quotes out, I get,
at: garbled time
This is all happening on a Mac OS 10.6 box running Rails 2.3 & Ruby 1.8.6
I've already messed around w/ BackgrounDrb, and decided its a total PITA. I need to be able to cancel the job at any time before it is due.
After playing around with irb a bit, here's what I found.
The backtick operator invokes the shell after ruby has done any interpretation necessary. For my test case, the strace output looked something like this:
execve("/bin/sh", ["sh", "-c", "echo at 12:57 < /etc/fstab"], [/* 67 vars */]) = 0
Since we know what it's doing, let's take a look at how your command will be executed:
/bin/sh -c "at 12:57 < RAILS_ROOT/lib/parking_timer.sh STRING_VARIABLE"
That looks very odd. Do you really want to pipe parking_timer.sh, the script, as input into the at command?
What you probably ultimately want is something like this:
/bin/sh -c "RAILS_ROOT/lib/parking_timer.sh STRING_VARIABLE | at 12:57"
Thus, the output of the parking_timer.sh command will become the input to the at command.
So, try the following:
output = `#{Rails.root}/lib/parking_timer.sh STRING_VARIABLE | at #{(Time.now + 60).strftime("%H:%M")}`
return render :text => output
You can always use strace or truss to see what's happening. For example:
strace -o strace.out -f -ff -p $IRB_PID
Then grep '^exec' strace.out* to see where the command is being executed.

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