I have a data file a.dat that is updated every few seconds. I wish to plot it in gnuplot every few seconds to see the changes
plot "a.dat"
What is the easiest way to do it? Thanks.
Make a script with a loop:
while (1) {
plot "a.dat"
pause 1 # waiting time in seconds
}
Execute it with gnuplot script.gp.
For purposes of code structure and debugging, you might prefer the following alternative:
plot "a.dat"
while (1) {
replot
pause 1
}
This has the advantage that you do not have to put a complicated plot command inside the loop and do not suffer from incorrect line numbers for the plot command in error messages (that happen in at least some version of Gnuplot).
Finally, if your Gnuplot is so old that it does not yet support loops, there is the alternative:
plot "a.dat"
pause 1
reread
With reread making the script interpreter jump to the beginning of the file again.
If gnuplot is called with plot commands in the command line (option -e) instead of a command script file, only the version
gnuplot -e "...plot command(s)...; while (1) { pause 1; replot; }"
worked in my case, the other version
gnuplot -e "...plot command(s)...; pause 1; reread;"
did not.
On windows 10, I have to kill the gnuplot task in the task manager, because if I close the gnuplot window with the close-window-button, the window opens again after one second latest. Does anybody have an idea of how to handle this in a more comfortable way?
Related
I have a code of more than 400 lines, and it takes a long time to run it. I'm at the stage of debugging and was wondering whther its possible to just run only a display command in a particular line? I mean like the option we have in PyCharm that we jsut press shift+enter at the desired line and it'll execute only that line.
Thanks
Short answer: No, you can not run just a single line (unless it is the first one).
Little longer, some way that could still be useful to save some time while debugging:
You could add $exit to run just the lines before that and skip the rest of your model.
If you have "static code" that takes some time at the start before you have other code that is work in progress and you want to save the time for the first part, you can use the "Save and Restart" facility of GAMS (see https://www.gams.com/41/docs/UG_SaveRestart.html). For this, you split the model in parts, lets say, the first part will be saved in longPrep.gms, the second part is wip.gms.
Then, you run gams longPrep.gms s=prep, which will generate a save file prep which will be your starting point for your second part by running gams wip.gms r=prep.
How can I ask the user to enter a value during the execution of a GnuPlot script?
I would like to use stdin to initialize some plotting parameters.
I have try to call :
a=system("read")
and
pause mouse keypressed
Without sucess.
Any help welcomed. Thanks
I assume you are on Linux. Your shell command must write something to stdout which gnuplot can read from stdin. Something like this should work:
print "Pleaser enter a number: "
a = system("read a; echo $a")
plot a*sin(x)
pause mouse close
Would it be an alternative to write a script in bash, python, ... which reads user input and calls gnuplot afterwards? (The links are my first google results, I have mainly read the title.)
I am trying a bit of experiments with airmon-ng script in Linux. Meanwhile i want to redirect output of a process "airodump-ng mon0" to a file. I can see the instantaneous output on the screen. The feature of this process is that it won't stop execution(actually it is a script to scan for AP and clients, it will keep on scanning) unless we use ctrl+c.
Whenever i try
airodump-ng mon0 > file.txt
i won't get the output in the file.
My primary assumption is that the shell will write it to the file only after completing the execution. But in the above case i stopped the execution(as the execution won't complete).
So to generalize i can't pipe the output of a running process to a file. How can i do that?
Or is there any alternative way to stop the execution of the process(for example after 5 seconds) and redirect the current output to a file?
A process may send output to standard output or standard error to get it to the terminal. Generally, the former is for information and the latter for errors, but in some cases, a process may mix them up.
I'm supposing that in your case, the standard error is being used. To get both of these to the output file, you can use:
airmon-ng mon0 > file.txt 2>&1
This says to send standard output to file.txt and to reroute 2 (which is the file id for standard error) into 1 (the file id for standard output) so that it also goes to the file.
I'm just switch to zsh and now adapting the alias in which was printing some text (in color) along with a command.
I have been trying to use the $fg array var, but there is a side effect, all the command is printed before being executed.
The same occur if i'm just testing a echo with a color code in the terminal:
echo $fg_bold[blue] "test"
]2;echo "test" test #the test is in the right color
Why the command print itself before to do what it's supposed to do ? (I precise this doesn't happen when just printing whithout any wariable command)
Have I to set a specific option to zsh, use echo with a special parameter to get ride of that?
Execute the command first (keep its output somewhere), and then issue echo. The easiest way I can think of doing that would be:
echo $fg[red] `ls`
Edit: Ok, so your trouble is some trash before the actual output of echo. You have some funny configuration that is causing you trouble.
What to do (other than inspecting your configuration):
start a shell with zsh -f (it will skip any configuration), and then re-try the echo command: autoload colors; colors; echo $fg_bold[red] foo (this should show you that the problem is in your configuration).
Most likely your configuration defines a precmd function that gets executed before every command (which is failing in some way). Try which precmd. If that is not defined, try echo $precmd_functions (precmd_functions is an array of functions that get executed before every command). Knowing which is the code being executed would help you search for it in your configuration (which I assume you just took from someone else).
If I had to guess, I'd say you are using oh-my-zsh without knowing exactly what you turned on (which is an endless source of troubles like this).
I don't replicate your issue, which I think indicates that it's either an option (that I've set), or it's a zsh version issue:
$ echo $fg_bold[red] test
test
Because I can't replicate it, I'm sure there's an option to stop it happening for you. I do not know what that option is (I'm using heavily modified oh-my-zsh, and still haven't finished learning what all the zsh options do or are).
My suggestions:
You could try using print:
$ print $fg_bold[red] test
test
The print builtin has many more options than echo (see man zshbuiltins).
You should also:
Check what version zsh you're using.
Check what options (setopt) are enabled.
Check your ~/.zshrc (and other loaded files) to see what, if any, options and functions are being run.
This question may suggest checking what TERM you're using, but reading your question it sounds like you're only seeing this behaviour (echoing of the command after entry) when you're using aliases...?
I have a shell script which asks for user input and depending on the input opens db connection using sqlplus and run some sql querys like drop table /create table/select/update. Is it possible that the sql part be run as background job,so that even if i lose vpn connectivity to the network,all the sql queries gets executed.
Also ,when the sql parts gets completed and user is prompted with another input the shell script comes to foreground and after getting the input again goes to background?
I have found some questions which tell us how to run the script in background,but i want to run ONLY some parts of the same script in background if possible(and come to foreground for user input).Though i can make multiple scripts too handle it(dividing the scripts in parts which needs to be called in background and calling them though another script),i would rather do it in a single script if possible.
You can break your main script up into functions / smaller scripts to achieve the desired behavior of a mix of background processes and foreground processes.
For example, in your main script:
#!/bin/sh
echo "Starting script..."
# do so more stuff here, maybe ask user for input
./run_background_process_1 &
# ask the user for some more input
./run_background_process_2 &
...
Use the & symbol at the end of script calls to denote that they should be run in the background.
(Updated) If you'd like to keep everything in 1 script, use functions to break up / encapsulate the parts of logic that you would like to run in the background. Call these functions by suffixing the call with &, same as above.
You can try the following example to see that it works:
#!/bin/sh
hello() {
condition="yes"
while [[ $condition== "yes" ]]
do
echo "."
sleep 1
done
}
# Script main starts here
echo "Start"
hello &
echo "Finish"
Remove the & after hello and you'll see that it behaves differently.
There are tools which allow you to keep scripts running despite loss of connection. For example, check out http://www.gnu.org/software/screen/ - one of its features is Programs continue to run when their window is currently not visible and even when the whole screen session is detached from the users terminal.
After search on internet i found out i can use three methods to make the script background :
1) using bg: How do I put an already-running process under nohup? .but unfortunately ,this didnt worked for me in ksh shell.
2) using coprocesses
3) using nohup
I decided to go with nohup as it was easier to implement. The sqlplus part which needed to be run in background ,i made another script of it and called it from the main script using nohup
nohup script-name.ksh ${parameter1} ${paramter2} &
This worked for me.