== Running scripts from your current directory or another directory or a directory in the $PATH ==
You can run a script from your current directory with ./ followed by the script name (without a space). I.E. '''./script.bash''' or '''./script.py''' Alternatively, if the script is in a directory that is specified in your $PATH environment variable you can execute the script by simply typing the name of the script without the ./. You can view your $PATH variable by issuing the command '''echo $PATH'''.
Since the scripts in our course are all located in /home/username/bin (which is part of our $PATH) you can execute them without the preceding ./
== Script Permissions ==
= Exercises =
Make sure you are in your home directory on c7host, and clone the github repo that contains templates for all the Python scripts you need this semester (including the sample hello.bash and hello.py below).
<pre>
git clone https://github.com/ops245/python
</pre>
These are a suggested order. You can do these exercises in any order, and change them in any way you like.
</pre>
* Create a bash script that will run your other script (hello.bash) twice. Feel free to reuse this prompt for any of the other scripts.
<pre>
#!/bin/bash
# Author:
# Date:
# Purpose: Run hello.bash twice
# Usage:
#
# Run hello.bash (just like you would execute it from the command line)
# Run hello.bash a second time
</pre>
* Now do it in python.
<pre>
#!/usr/bin/env python3
# Author:
# Date:
# Purpose: Run hello.py twice
# Usage:
#
# Import the operating system module
# Run hello.py (using the os.system function and passing it the name of the script)
# Run hello.py a second time
</pre>
* Run this new script from different locations, and see if it always works. Fix it if it doesn't.
* Create a bash script to display the contents of /etc/sysconfig/network-scripts/ifcfg-ens33
** Pipe the output to cat
*** Pipe that output to cat. See if you understand why that doesn't seem to do anything
* Create a bash script which will use cat and grep to find the line with BOOTPROTO in /etc/sysconfig/network-scripts/ifcfg-ens33
** Modify that script so that it doesn't need cat anymore.
* Create a bash script in which you will create a variable called BP.
** Assign to that variable the value BOOTPROTO="dhcp" (the equal sign and quotes are part of the value).
** Use the cut command to retrieve the part between the double-quotes (in this case that's: dhcp).
** Save the result in a variable, and print that variable.
* Combine the two scripts above into one. The script should tell you what the value of BOOTPROTO from /etc/sysconfig/network-scripts/ifcfg-ens33 is.
*Create a python script that will prompt the user for the name of the interface they want to search (e.g. ens33), then prompt them for the parameter they wish to see.
**Store the responses from the user in variables and use them to grep the appropriate file for the parameter the user asked for. Display it's current value.
**Note: As we have not covered conditional statements or loops in python yet, you can assume the user always provides usable responses.
* Use the ls and wc commands to find how many log files there are in /var/log/
** Add a grep command to find how many of a certain type of log file there are (e.g. vmware-network log files)
* Use the history and grep commands to find any command you ran in the past that contained a certain keyword (like .sh or cat)
* Write a bash script which will use the whoami, hostname, date, and lvs commands to create a report.txt file containing all that information.
** Set it up so that the date (in YYYY-MM-DD format) is in the filename of the report, e.g. report-YYYY-MM-DD.txt
* Write a bash script that will ask the user for a process name, will check whether that process is running, and if it is: it will print "The process is running". If it isn't: it will print "The process is not running".
** Modify that script to include the number of processes with that name that are running.
* Write a script that will use a for loop and the cut command to get a list of usernames from the /etc/passwd file and print one username perline.
** For each user: using an if statement check whether the directory /home/thatusername exists and then each line will look like: "user1: home directory does not exist" or "user2: home directory exists".
** Instead of checking for /home/thatusername check for the home directory in the passwd file line for that user.