Shell Scripting

hello

first year of learning linux and bash script
Now i wrote a bash script with a function.
Today i recieved a email from my teacher that 1 function only can have 1 command and no more then 1?

thats a part of the script

Code:

function tx_unreachable_msg()
{
LOGLINE="[$DATE] no ip service unreachable"
typewriter "$NOIPSERVICE niet bereikbaar" .1
sleep 1 
typewriter "Mail wordt verzonden naar $email" .1
mail -s "NO ip mail error" "$email"<<EOF
dynupdate.no-ip.com niet bereikbaar @ $DATE
EOF
}

it's part dutch part english but the point is that the first LOGLINE is forbidden in the function because i use the functie to send a mail end not to write a logline but that's a part of the command in my case?

So what does this function?
If the no ip service is unreachable then it's write to /etc/var/log/no-ip and after the sleep it's send a simpel mail to the adres in the variabele mail.

i read here at the first line:
Quote:
Shell functions are a way to group commands for later execution using a single name for the group.
so is it true that my function is wrong and so no can someone point me to a website where it's say that more commands are allow in 1 function0

grts b

I have many hosts as following. But those hosts are dual operating system (Linux and Windows). I always run program background. If someone is using Linux, it is fine. But if someone is using windows or the host is offline. Then, I cannot use ssh. The way I do preiviously is first ssh one by one. And then find the hosts which are offline or windows. And write them down one by one. And then ssh to hosts except them. Let us assume the number of programs is less than the total available hosts. Can someone write a shell script to output the all available hosts to a file like "host_available"?
Here is the host file.
https://www.dropbox.com/s/vbz6w864y3...tlist.txt?dl=0
I am using ssh to connect the computers on campus. If the computer I am trying to connect is offline or using windows, the ssh will take long time, and finally it will failed. I write a shell script to generate the hostlist
Code:

#!/bin/bash
for i in `seq -w 1 28`
do
echo "c15-0330-$i.ad.mtu.edu"
# I would like to add a command here to see whether ssh c15-0330-$i.ad.mtu.edu it succeeds or not. And then output a #file which contains the all available host.
done
for i in `seq -w 1 20`
do
echo "c28-0112-$i.ad.mtu.edu"
done
for i in `seq -w 1 20`
do
echo "c28-112a-$i.ad.mtu.edu"
done

I do not how to set a certain time to see whether connection is successful or not (see the comment in the shell script).

I have serveral nodes related files under /var/lib/ directory as shown below:

Code:

machine001.cluster.org 
machine002.cluster.org
machine003.cluster.org
machine004.cluster.org

I am trying to write a shell script which first finds out how many number of files are present in this directory. Then it should fetch the first name like machine001, machine002, machine003 etc. Then it should fetches ipaddress, hostname and netmask under machine001 first, then store it in some variable. Repeat this for all the nodes. How will the script look like?

Hi,
I am looking for a simple shell script that allows for sftp to be run from the server to another server (Windows). I would like the script to be passed parameters suchas destination server, Id, password, Directory structure/folder name, file name etc...
Need some help to know how to start with and it would be great if someone help me with any sample sftp shell script

i have a javascript code and i want to convert it into bash or shell script code to run in linux machine

document.onkeydown = function (e) {
if(e.which == 9){
return false;
}
}

thanks in advance

Hello am a newbie to linux,
I tried to install cygwin for windows,all i need is i need to write a shell program for a batch file i already have, I am not able to do this.
My batch file content looks like

SET JAVA_HOME=..\jdk
SET CLASSPATH="%CLASSPATH%;../lib/A.jar;../lib/slf4j-api-1.6.1.jar;../lib/slf4j-simple-1.6.1.jar"

%JAVA_HOME%\bin\java.exe com.A ../conf/C.properties

PAUSE

this works perfectly, I try to write a shell program which is failing when i check it through cygwin. i am not able to set the export to java_home.
The pblm i face is say my current directory where my shell program is 'Z'
then i want to get back to 'y' where X has two sub folders y and z

X
-Y (is jdk )
-Z (where shell pgm resides)

cd ../ or any combination of cd doesnot work in my shell script.

Please help me. Any help is greatly appreciated

I want to write a bash shell script to execute a command for one minute then stop that command (ctrl c) pause for 10 seconds then run another command for one minute then stop that command pause for 10 seconds then go back to the begining of the script and loop indefinetly.

First I want to run this command for one minute;

reaver -i mon0 -c 6 -b "mac address" -a -vv

stop previous command and pause for 10 seconds

Then run this command for one minute;

airodump-ng -i mon0

stop previous command and pause for 10 seconds

Then recall reaver command and continue to loop through until reaver spits out result.

I imagine I will need to create a function for each command, an if statement and an ifelse statement and I will need the break and sleep commands. but I am not sure about the syntax, PLEASE HELP THIS NOOB!

Hi guys I just started learning Linux, Need some help writing the script for the following

1. An argument of the form-6 sets the script to display the first 6 lines of the succeeding file(s). the default should be 5.

2. Anything else of the form "-x" should produce an error message

3. For a file name, display the first _lines of the file

Hello.
How can I write an Script that enter my password for "sudo" command automatically?
for example, I want to run a command that need root permission and when I write it in a bash script, it ask me "sudo" password for user but how can I automate it?
Can it possible for other program like logging via SSH too?

Thank you.

books say that PATH variable contains the locations where the shell searches the commands to execute them.

I created a shell script and saved it in /home/user/Downloads directory and then i ran this script from the /home/user/Downloads directory. It did not execute.

however when i did set the path
export PATH=$PATH:/bin/sh within /home/user/Downloads directory, the shell script executed. Does it not mean that PATH variable is holding the locations of the shell program rather than the commands that are to be executed?

everytime i have to give the location of the shell i.e /bin/sh in the PATH variable no matter from where i am executing my script