I'm very very new to bash scripting and just wanted to have a little play around.
Ive created a file containing 2 IP addresses and 2 netmasks so far I've got the code to print the addresses and netmasks from that file and work out the addresses network number, I am just wanting to add more code which simply works out how many hosts are on that network and how many other networks share the same netmask.
I know how to do this on paper, pretty simple.
Very basic and I am aware, just want some simple pointers in bash.
Try doing this using ipcalc in a shell :
Related
I am required to read the serial number of connected J-Link (I use J-Link Compact Plus from Segger) via the command line.
I am using tools from Segger such as JFlash.exe and JLink.exe
I managed to find a way to read a serial number via JLink.exe by executing the following command:
JLink.exe -CommanderScript -CommandFile GetSerial.jlink
Where GetSerial.jlink is a custom file that I have created and it looks like:
ShowEmuList
exit
The response is as following:
The above method seems to work fine but I am not convinced that this is the most optimal way.
My questions:
Is it possible to read the serial number using JFlash.exe instead of JLink.exe. Since I use JFlash.exe from flashing, I would prefer to rely on a single tool instead of 2.
If the answer to above is no. I would like to know if there is any way to optimise the JLink.exe command to read the device serial number. I do not fully understand why do I need to pass GetSerial.jlink as an argument to the command. I would much rather prefer something like:
Jlink.exe -ShowEmuList
But the above does not seem to work:
Thanks in advance for the help.
I'd like some advice on what vocabulary to use to describe the following. Having the right vocabulary will allow me to search for tools and ideas related to the concept
I'd like to say a script is SomeWord if it is expected to produce the same output no matter where it is run.
For example, the following script is not SomeWord:
#!/bin/bash
ls ~
because of course it depends on where it is executed.
Whereas the following (if it runs without error) is expected to always produce the same output:
#!/bin/bash
echo "hello, world"
A more useful example would be something that loads and runs a docker or singularity container in a way that guarantees that a very particular container image is being used. For example by retrieving the singularity image by its content-hash.
The advantages of SomeWord scripts are: (a) they may be safely run on a remote system without worrying about the environment and (b) their outputs may be cached.
The best I can think of would be "deterministic" or some variation on "environment independent" or "reproducible".
Any container should be able to do this, as that is a big part of why the tech developed in the first place. Environment managers like conda can also do this to a certain extent, but because it's just modifying the host environment it's possible to be using non-conda binaries without realizing it.
Suppose I am working on LocalA (username userA). I use ssh to tunnel to RemoteB (username userB), then to RemoteC (username userC), then finally to RemoteDestinationD (username userD).
It would look something like the following:
userA#LocalA$ ssh userB#RemoteB
userB#RemoteB$ ssh userC#RemoteC
userC#RemoteC$ ssh userD#RemoteDestinationD
userD#RemoteDestinationD$
Suppose I forget which series of connections I used to connect from LocalA to RemoteDestinationD. It could have been one jump (e.g. userA#LocalA$ ssh userD#RemoteDestinationD) or three jumps (as in my example above). How could I programmatically determine what my series of jumps was? ("Scroll through your history, dummy!" doesn't count....)
I'd like a BASH script that would output something like the following:
userA#LocalA$ --> userB#RemoteB
userB#RemoteB$ --> userC#RemoteC
userC#RemoteC$ --> userD#RemoteDestinationD
Any ideas?
Thanks in advance!
There is no good way to do this, I suspect. There are a bunch of true hacks you could do if you were willing, such as turning on X11 port forwarding and using different ports for counting.
Or, more obnoxiously:
sshcount=0
ssh userA#RemoteA "echo sshcount=$(($sshcount+1)) > .bashrc; bash"
And from there do something similar to get to B, so sshcount keeps incrementing.
Clearly this should be done via overwriting a .sshcountrc file or something, and source that from the .bashrc. And then, you might need to make the file name dependent on some munging of $SSH_TTY if you want to support doing parallel versions of this.
And the whole thing is really a hack so maybe you shouldn't anyway and you should solve the problem another way. Or remove the need for counting in the first place.
Quick bash/terminal question -
I work a lot on the command line, but have never really had a good idea of how to manage running processes with it - I am aware of 'ps', but it always gives me an exceedingly long and esoteric list of junk, including like 30 google chrome workers, and I always end up going back to activity monitor to get a clean look at what's actually going on.
Can anyone offer a bit of advice on how to manage running processes from the command line? Is there a way to get a clean list of what you've got running? I often use 'killall' on process names that I know as a quick way to get rid of something that's freezing up - can I get those names to display via terminal rather than the strange long names and numbers that ps displays by default? And can I search for a specific process or quick regex of a process, like '*ome'?
If anyone has the answers to these three questions, that would be amazingly helpful to many people, I'm sure : )
Thanks!!
Yes grep is good.
I don't know what you want to achieve but do you know the top command ? Il gives you a dynamic view of what's going on.
On Linux you have plenty of commands that should help you getting what you want in a script and piping commands is a basic we are taught when studying IT.
You can also get a look to the man of jobs and I would advise you to read some articles about process management basics. :)
Good Luck.
ps -o command
will give you a list of just the process names (more exactly, the command that invoked the process). Use grep to search, like this:
ps -o command | grep ".*ome"
there may be scripts out there..
but for example if you're seeing a lot of chrome that you're not interested in, something as simple as the following would help:
ps aux | grep -v chrome
other variations could help showing each image only once... so you get one chrome, one vim etc.. (google show unique rows with perl or python or sed for example)
you could use ps to specifiy one username... so you filter out system processes, or if more than one user is logged to the machine etc.
Ps is quite versatile with the command line arguments.. a little digging help finding a lot of nice tweaks and flags in combinations with other tools such as perl and sed etc..
Ok, I have tried to google this and keep running into things that are close, but not quite there. I mess with them for a few hours and can't bridge it across to what I need.
Requirements: Read a list of computer names and add them to specific OUs.
The list can be formated however, but right now I have it as a csv.
/////////
Comp1,Computers,cold,Alaska,mydomain,com,
Comp2,servers,New Jersey,test,temp,training,Room3,trainers,mydomain,com,
Comp3,computers,New Jersey,test,temp,training,Room3,students,restricted,mydomain,com
Comp4,computers,New Jersey,test,temp,training,Room3,students,power users,mydomain,com
////////
As you can see, the domains portion is not the same on all the machines.
I tried using a vbscript but all I would get is "unable to connect to LDap" so I was thinking about storing the lines in an array and using dsadd and building the command line from the variables in the array.
I already have the portion written to browse for the file, and dsquery, dsadd, etc are all on the server that this will be run from.
This is probably a lot easier than I am trying to make it, I tend to over complicate things if I don't finish it right away.
Look at this:
Automating the creation of computer accounts