cs3423 Assignment 2 SED

This assignment has two parts p2a and p2b.

Problem A:

We need a new mechanism to identify apps that have been installed on the system and have never been removed. We will use the dpkg.log file to get information of the installation history; however, it just handles one server. You can find dpkg.log in "/usr/local/courses/rslavin/cs3423/2018Sp/assignment2". Copy this file to your project directory.

The format of the dpkg.log is similar to this (the yellow highlighted portions are comments):

The following line is a command to remove grublegacyec2.

20160323 20:54:27 remove grublegacyec2:all 0.7.50ubuntu1.17

The following status lines are intermediate steps in the removal of the grublegacyec2 program

20160323 20:54:27 startup packages purge

20160323 20:54:27 status configfiles grublegacyec2:all 0.7.50ubuntu1.17 20160323 20:54:27 status configfiles grublegacyec2:all 0.7.50ubuntu1.17

The following is an example of a short command
20160913 02:42:27	install	language

packenbase:all 1:14.04+20160720

20160913 02:42:27 startup archives unpack

20160913 02:42:27 status halfinstalled languagepackenbase:all 1:14.04+20160720

20180119 21:33:09 install flex:amd64 2.5.3510.1ubuntu2

20180119 21:33:09 status halfconfigured mandb:amd64 2.6.7.11ubuntu1

20180119 21:33:09 status halfinstalled flex:amd64 2.5.3510.1ubuntu2

20180119 21:33:09 status triggerspending installinfo:amd64 5.2.0.dfsg.12

20180119 21:33:09 status triggerspending mandb:amd64 2.6.7.11ubuntu1

20180119 21:33:14 status installed libfldev:amd64 2.5.3510.1ubuntu2

20180119 21:33:14 status unpacked flex:amd64 2.5.3510.1ubuntu2

20180119 21:33:14 status unpacked libfldev:amd64 2.5.3510.1ubuntu2

remove

remove

20180119 21:33:25 flex:amd64 2.5.3510.1ubuntu2

20180119 21:33:25 libfldev:amd64 2.5.3510.1ubuntu2

20180119 21:33:25 startup packages remove

20180119 21:33:25 status configfiles flex:amd64 2.5.3510.1ubuntu2

20180119 21:33:25 status configfiles flex:amd64 2.5.3510.1ubuntu2

20180119 21:33:25 status configfiles libfldev:amd64 2.5.3510.1ubuntu2

Find any program which has been installed but not removed from this file. For instance, in the example above the program languagepackenbase (5^th line) meets the criteria but the program flex (8^th line) does not since it was removed later.

We suggest creating two files, one with all the installed programs and one with all the removed programs, and using the difference of the two to find only those who have been installed but not removed. Example:

Installed file:

languagepackenbase flex

Removed file:

grublegacyec2 flex libfldev

Matching on install.

Where is the word install we want to match which indicates that the program was installed? If we just match "install" anywhere on the line, it could match programs which have the word install in the name. Also, we would match status lines (e.g., status installed) that are only intermediate steps in the installation.

File difference.

We can use the comm command to find the lines that are unique across two files. Note that comm expects the files to be sorted. See the comm man page for details.

Problem B:

For this problem, we will want to get the same result, but this time we are going to consider if a program was installed again after being removed.

Steps:

Consider using the installed/removed files from the previous problem

The uniq c command can be used to get a count of each unique value

Then you only need to find those items which have a higher install count than removed count

You may use intermediate output files to store programs and their install/remove counts, just be sure to remove them by the end of execution

Hint: grep can be used to search a particular file using a regular expression. If you can identify the number of installations for an application, you can use grep to search for the same application in your temporaryuninstallcount file to compare values.

What to turn in

A LastnameFirstname.zip file containing at least the following: o p2a.bash a bash script which executes part A. The final result should be output to p2a.out using p2AInstalled.sed and p2bRemoved.sed

o p2aInstalled.sed a sed file which produces records of installed files o p2bRemoved.sed a sed file which produces records of removed files o p2b.bash a bash script which executes part B. The final result should be output to p2b.out

Be sure that your scripts remove any intermediate files created. After running p2a.bash and p2b.bash (the only scripts which should be run), the only new files that should exist are p2a.out and p2b.out.