[SOLVED] need to create a humongous data base

Dafydd · 10-19-2013, 09:29 PM

I need to create a humongous data base to test some code.

How do I get the output of

Code:

 head -$LINE $1 | tail -1

into a variable to be used later?
The current output is

Quote:

Milissa Greener
Temple, TX
7/1/2013,,
Rebecca Loeby
La Grange, TX
4/28/2013,,
Carrie Elkins
Bastrop , TX
8/23/2013,,

and I would like to be

Quote:

8/23/2013,Carrie Elkins,Bastrop, TX

Code:

#!/bin/bash

function randomline() {
RAND=`cat /proc/sys/kernel/random/uuid | cut -c1-4 | od -d | head -1 | cut -d' ' -f2`
LINES=`cat "$1" | wc -l`
LINE=`expr $RAND % $LINES + 1`
head -$LINE $1 | tail -1
}

i=0
loop_count=7
while [ "$i" -lt "$loop_count" ];  do
    gigday=$(($RANDOM%30));
    gigmonth=$(($RANDOM%12));
    gigyear=2013;
 
    randomline "artists";
    randomline "towns";
	
	echo "$gigmonth"/"$gigday"/"$gigyear","$gigartist","$gigtown";
	

	i=$(($i + 1));
  
done

The content of 'artists' and 'towns' take this format.
artosts"

Quote:

Amy Speace
emily elbert
Raina rose
Rebecca Loeby
Carrie Elkins
Danny Schmidt
Kacie Jones
Milissa Greener
Susan Gibson
Jana Pochop
Marcia Ball
Marian Call
Sara Hickman
Ruby Jane

towns:

Quote:

Dallas, TX
Ft Worth, TX
Waco, TX
Temple, TX
Austin, TX
San Antonio, TX
La Grange, TX
Bastrop , TX
Austin, TX
Houston, TX
Galveston, TX
Pt Auther, TX
Odessa, TX
Conroe, TX
The Woodlands, TX
Huntsville, TX

Help would be appreciated.
Dave

druuna · 10-20-2013, 05:14 AM

Change:
head -$LINE $1 | tail -1
to
retValue=$(head -$LINE $1 | tail -1)

Add the following bold lines:

Code:

    randomline "artists";
    gigartist="$retValue"
    randomline "towns";
    gigtown="$retValue"

About your randomline function: This can be done simpler using the shuf or rl command.
Using shuf:

Code:

function randomline() {
  retValue=$(shuf -n 1 $1)
}

Using rl:

Code:

function randomline() {
  retValue=$(rl -c 1 $1)
}

Dafydd · 10-20-2013, 04:44 PM

Thank you for the reply and solution I got close several times. I tried with an ' and a " bu n cneve a (,

Everything works as planed. Now to try your other recommendations. I did not know that shuf amd rl existed. Maybe I should spend some time and go back and reread my book, Linux in a Nutshell

druuna · 10-21-2013, 01:40 AM

You're welcome.

BTW: These 2 are the same, the second one is being preferred:

Code:

`head -$LINE $1 | tail -1`
$(head -$LINE $1 | tail -1)

Also have a look at this thread here at LQ: notation difference: var=`command` and var=$(command)

About shuf and rl: The shuf command is part of coreutils and should be present on most, if not all modern Linux distro's. rl might not be present out-of-the-box.

Dafydd · 10-21-2013, 11:03 AM

Quote:

Originally Posted by druuna

About shuf and rl: The shuf command is part of coreutils and should be present on most, if not all modern Linux distro's. rl might not be present out-of-the-box.

This was my case. I used shuf, rl was a 'command not found'.

Thanks for the link.
D