CSCI 57 and 65: Introduction to Unix Courses

Extra Credit Scripts

ASSIGNMENT DUE: see calendar on the web

Write a getinfo script (3 points)

Write a script called getinfo

This script will take one command line argument which will be the name of a program (additional arguments can be ignored).

This script will then run whatis, whereis and type -a providing the same argument that was passed to the script getinfo. Here is an example where I call getinfo on tiglon three different times:

toddj@tiglon:~$ ./getinfo type
type            type (1)        - write a description of command type
type            type (1)        - write a description of command type
type: /usr/bin/type
type is a shell builtin
type is /usr/bin/type


toddj@tiglon:~$ ./getinfo ls
ls              ls (1)          - list directory contents
ls              ls (1)          - list contents of directory
ls              ls (1b)         - list the contents of a directory
ls              ls (1)          - list contents of directory
ls              ls (1b)         - list the contents of a directory
ls: /usr/bin/ls /usr/ucb/ls
ls is /opt/gnu/bin/ls
ls is /usr/bin/ls
ls is /usr/ucb/ls
ls is /usr/ucb/ls
ls is /opt/gnu/bin/ls

toddj@tiglon:~$ ./getinfo cd
cd              cd (1)          - change working directory
cd              cd (1)          - change working directory
cd: /usr/bin/cd
cd is a shell builtin
cd is /usr/bin/cd

When getinfo is called with no arguments it will print the usage message as below:
```
toddj@tiglon:~$ ./getinfo 
Usage: getinfo COMMANDNAME
please try again...
```
(Notice that when getinfo was called without any arguments there was no additional error messages (for example, "usage: whatis keyword ..." or "whereis [ -sbmu ] [ -SBM dir ... -f ] name..."). Therefore this script will need to check that it was called with at least one command line argument.
I recommend writing this script using bash but you can use any of the following if you prefer sh, csh, tcsh, ksh. or perl.
To run the script you will need to have execute permission on it and have it in your PATH (or give the path like I did above ./getinfo).
Please include one line of documentation

# getinfo script - written by YOUR NAME

(You can document it more if it helps you but one line similar to above is all I care about).
Include a print out of this script with your turn-in

Write a simple log rotate script (3 points)

Write a script called logr
This script will take one or more arguments (passed on the command line). (you have to use a for loop to
For each argument it will move that file to filename.1 (adds the .1 extension)
Next it will compress that file using gzip (gzip will add the additional extension .gz). Use for "force" option so that this script does not prompt whether or not filename.1.gz should be overwritten on subsequent invocations (read the man page).
Finally it will create an empty file of the same name
If this script is called without any arguments print some kind of error message.
If this script is called with any arguments that do not exist print an error message saying so.
Make sure this script works by actually running it.
I recommend bash but you can use any of the following for implementation sh, ksh, csh, tcsh, zsh, but NOT perl.
Include at least one line of documentation with the name of the script, what it is for, and YOUR NAME
TURN-IN

print out of this script.

Some additional explanation

If I run logr on a file named "somelog" in the same directory as somelog there would now be a file named "somelog.1.gz" and an empty file named "somelog"
If I run logr * in a directory that contained files a, b and c. There would now be:

a.1.gz (the original file compressed)
b.1.gz (the original file compressed)
c.1.gz (the original file compressed)
a (an empty file)
b (an empty file)
c (an empty file)

Hints:

You can use gzip to compress and gunzip to decompress .gz files
You can use the command touch to create empty files (for example, "touch somefile" creates an empty file named "somefile").
The exists script found in http://www.ecst.csuchico.edu/~toddj/257/scripts/ gives an example of testing for if a file exists.
Look at the other example scripts I've written to see how to use for loops and if statements.

Alternatively, write any sort of log rotate that is cooler than this in some way.

Possiblities include

After archiving the log file, ftp'ing it to another machine
Script only takes argument of one file to rotate but lets you specify things like how many backups to keep
Instead of specifying how many backups to keep the script automatically uses how ever many you already have, a.1.gz a.2.gz a.3.gz
Command line parameters that can turn compression "on" or "off" or allows you to specify the type of compression gzip, bzip2, zip, etc.
Instead of naming files with the extension .1 .2 .3 it could give dates like .2-11-2004 or 02112004 or similar

Text2dos Script (4 points)

Write a script called text2dos
This will have some similarities to the addextension script found in http://www.ecst.csuchico.edu/~toddj/257/scripts/
This script is for converting text files from unix format to dos format. It will take one or more arguments (passed on the command line) which are the names of unix style text files and then for each argument it will run the program unix2dos and then add the file extension .txt to all of the files
When this script is called with the -r option it will do the opposite. For each argument it will run the command dos2unix and remove the file extension .txt if it exists. (You can see my rabbit script or bash documentation to see how you can match an extension and remove it in bash).
If this script is called without any options it should print a usage message. Additionally if it was called with the -r option but without any file arguments this script should print a usage message.
I recommend bash but you can use any of the following for implementation sh, ksh, csh, tcsh, zsh, but NOT perl.
Include at least one line of documentation with the name of the script, what it is for, and YOUR NAME
TURN-IN

a printout of this script

Hints:

Use a for loop for dealing with a large list of arguments
Use an IF statement to see if it was called with the -r option
If it was called with the -r option you will want to use a shift
Use an IF statement to see if it was called with the right number of arguments
The JPGtojpg script found in http://www.ecst.csuchico.edu/~toddj/257/scripts/ gives an example of testing for a file extension.
In unix you rename files with the mv command