use a variable as part of another variables name - linux

Bash question!
so I have n arguments, and for each argument I'd like to to do a for loop and assign variables to hold characteristics of each argument. for example I have a script that runs in a continuous while loop and looks at user activity in my network... this is a simple outline of what my problems are:
while true
for argument
do
# build an array to hold times
"$user"_times =()
# set a boolean value
"$user"_boolean=true
if [ ""$user"_boolean" = true ]
then
echo $user logged on
"$user"_times+=( timestamp )
fi
done
done
exit 0
the real script will look at user activity, update the boolean based on certain user behavior, and log some user activity info in the array- but I'm trying to get this to work so I can add the easy meat. what should the syntax be? I'm having a hard time making the variables work.

Since bash doesn't support hash/maps, I'd consider perl/python to store user activity against their hash id. You also have access to vectors for variable sized activity details, eg a hash of userid's containing a vector of activities.
Python script to list users and groups

Related

Is there a bash function for determining number of variables from a read provided from end user

I am currently working on a small command line interface tool that someone not very familiar with bash could run from their computer. I have changed content for confidentiality, however functionality has remained the same.
The user would be given a prompt
the user would then respond with their answer(s)
From this, I would be given two bits of information:
1.their responses now as individual variables
2.the number of variables that I have now been given: this value is now a variable as well
my current script is as follows
echo List your favorite car manufacturers
read $car1 $car2 $car3 #end user can list as many as they wish
for n in {1..$numberofmanufacturers} #finding the number of
variables/manufactures is my second question
do
echo car$n
done
I am wanting to allow for the user to enter as many car manufacturers as they please (1=<n), however I need each manufacturer to be a different variable. I also need to be able to automate the count of the number of manufacturers and have that value be its own new variable.
Would I be better suited for having the end user create a .txt file in which they list (vertically) their manufactures, thus forcing me to use wc -l to determine the number of manufacturers?
I appreciate any help in advance.
As I said in the comment, whenever you want to use multiple dynamically created variables, you should check if there isn't a better data structure for your use case; and in almost all cases there will be. Here is the implementation using bash arrays. It prints out the contents of the input array in three different ways.
echo List your favorite car manufacturers
# read in an array, split on spaces
read -a cars
echo Looping over array values
for car in "${cars[#]}"
do
echo $car
done
echo Looping over array indices
for i in ${!cars[#]}
do
echo ${cars[$i]}
done
echo Looping from 0 to length-1
let numcars=${#cars[#]}
for i in $(seq 0 $((numcars-1)))
do
echo ${cars[$i]}
done

Maximo automation script get user securityGroup

I would like to get the security group of the user in a Maximo automation script so I can compare it. I need to know if the user in in MaxAdmin or UserUser group to execute the reste of my script. My scripts are in Python
how could I get that Info?
There are some implicit variables available to you in an automation script (check the IBM Automation Script guide), one of which is the current user's username. There is also the :&USERNAME& special bind variable that gets replaced with the current username. You can use one of those as part of the query to fetch a GroupUser MBO and then check the count of it afterward.
I'm going off of memory here so the exact names and syntax probably differ, but something like:
groupUserSet = MXServer.getMXServer().getMboSet("GROUPUSER", MXServer.getMXServer().getSystemUserInfo())
groupUserSet.setWhere("userid = :&USERNAME& and groupname in ('MAXADMIN', 'USERUSER')")
# Not really needed.
groupUserSet.reset()
if groupUserSet.count() > 0:
# The current user is in one of the relevant groups.
else:
# The current user is not in one of the relevant groups.
groupUserSet.close()
It's worth noting that the kinds of things tied to logic like this usually don't need an automation script. Usually conditional expressions, normal security permissions or reports can do what you need here instead. Even when an automation script like this is needed, you still should not do it based on group alone, but based on whether the user has a certain permission or not.
EDIT
To do this with permissions, you would add a new sigoption to the app with an id along the lines of "CANCOMPPERM" (with a more verbose description) and grant it to those two groups. Make sure everyone in those groups logs out at the same time (so nobody in those two groups are logged into the system at a given point) or else the permission cache will not update. Your code would then look something like this:
permissionsSet = MXServer.getMXServer().getMboSet("APPLICATIONAUTH", MXServer.getMXServer().getSystemUserInfo())
permissionsSet.setWhere("optionname = 'CANCOMPPERM' and groupname in (select groupname from groupuser where userid = :&USERNAME& )")
# Not really needed.
permissionsSet.reset()
if permissionsSet.count() > 0:
# The current user has the necessary permission.
else:
# The current user does not have the necessary permission.
permissionsSet.close()
I think there are even some helper methods in Maximo's code base that you can call to do the above for you and just return a true/false on if the permission is granted or not.

Allstar Node Programming

I'm almost completely new to Linux programming, and Bash Scripts. I build an amateur radio AllStar node.
I'm trying to create a script that looks at a certain variable and based on that info decides if it should connect or not. I can use a command: asterisk -rx "rpt showvars 47168. This returns a list of variables and their current values. I can store the whole list into a variable that I define, in my test script I just called it MYVAR but I can't seem to only get the value of one of the variables that's listed.
I talked to someone who knows a lot about Linux programming, and she suggested that I try CONNECTED="${MYVAR[3]}" but when I do this, CONNECTED just seems to become a blank variable.
What really frustrates me is I have written programs in other programming languages, and I've been told Bash scripts are easy to learn, but yet I can't seem to get this.
So any help would be great.
how did you assigned your variable?
It seems to me that you want to work with an array, then:
#!/bin/bash
myvar=( $( asterisk -rx "rpt showvars 47168 ) )
echo ${mywar[3]} # this is your fourth element
echo ${#myvar[#]} # this is the total of element in your array
be careful that index in an array starts at 0

Linux Date not showing the date value sometimes

I have defined a variable inside one of the shell script to create the file name with date value in it.
I used "date +%Y%m%d" command to insert the current date which was defined in date_val variable.
And I have defined the filename variable to have "${path}/sample_${date_val}.txt
For few days it was creating the file name properly as /programfiles/sample_20180308.txt
But today the filename was created without date as /programfiles/sample_.txt
When I try to execute the command "date +%Y%m%d" in linux, it is returning the correct value - 20180309.
Any idea why the filename was created without the date value ??? . I did not modify anything in my script too. So wondering what might have gone wrong.
Sample excerpt of my script is given below for easy understanding :
EDITED
path=/programfiles
date_val=$(date +%Y%m%d )
file_name=${path}/sample_${date_val}.txt
Although incredibly unlikely, it's certainly possible for date to fail, based on the source code. Under the covers, it calls either clock_gettime() or gettimeofday(), both of which can fail.
The date program will also refuse to output anything to standard output if the date from either of those two functions is out of range during the call to (which is possible if they fail).
It's also possible that the date program could "disappear" for various reasons, such as actually being hidden or permissions changed, or a shortage of resources like file handles when attempting to open the executable.
As mentioned, all these possibilities are a stretch, unlikely to happen in the real world.
If you want to handle the case where you get inadequate output from date, you can simply try until you get a valid one, something like (with the possibility of adding some limit to detect if it's never any good):
todaysDate="$(date +%Y%m%d)"
while [[ ! $x =~ ^[0-9]{8}$ ]] ; do
sleep 1
todaysDate="$(date +%Y%m%d)"
done
# todaysDate now guaranteed to be eight digits.

Condition to check a variable value present or not

there is a autosys job, whicn has 3 jobs init. all 3 jobs call a common script and there 3 diffrent profiles one for each of them.these 3 jobs called from 3 different machines
.Each profile has got a varialble and this varible contains a fixed value specfic to the machine.
In the comomna scirpt i wnt to execute code based on teh value in the variable passed.
If the variable matches the value in the profile of a machine the code for that machine will be executed.how can I check if the varialbe received in the common script is also present in the profile of the machine.
Thanks
Old fashioned way I fall back on (in sh) is :
if [ -z "$VarToCheck" ] ; then
echo "Variable not set"
fi
There is probably a more correct way though. Do you care if a variable exists but has 0 length?

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