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frankie_DJ

10-04-2006 04:48 PM

Advice for a fairly simple(?) script

Hi everyone,

I have bunch of files of this format

Title
number1,number2
10000
12000
L
0.7
0.7
0.0

I want to write a shell script that writes for each file:

Temperature: number1
Time: 2nd_line * 6th_line
Cooling Rate: (number1-number2)/(6th_line*4th_line)

What's the most efficient way to go about this? I am not so bad with bash untill I have to batch process bunch of files like this. I know tiny little bit of awk and sed. Should I use them? Would it be an overkill if I do? Would expr utility be helpfull here? Please help.

jonaskoelker

10-04-2006 05:08 PM

Code:

IFS='

' # or possibly $'\n' if you like that syntax better

for fp in those-files/*; do {

  read title # Title

  IFS=',' read number1 # number1

  read number2 # number2

  read line2 # 10000

  read line3 # 12000

  read line4 # L

  read line5 # 0.7

  read line6 # 0.7

  echo "Temperature: $number1"

  echo "Time: $(($line2 * line6))"

  echo "Cooling Rate: $((($number1 - $number2) / ($line6 * $line4)))"

} < $fp; done

I think...

ghostdog74

10-04-2006 07:04 PM

Quote:

Originally Posted by frankie_DJ

Alternative in Python:

Code:

#!/usr/bin/python

data = open("test.txt").read().split()

temp1,temp2 = data[1].split(",")

thetime = int(data[2]) * float(data[-2]) 

cooling rate = temp1 - temp2 / ( float(data[-2]) *  int(data[4] ) )

pete1234

10-04-2006 08:00 PM

Another way in bash:

Code:

#!/bin/bash -

#



for i in $(ls whatever); do

  TEMP=(`sed -n 2p $i | awk -F"," ' /[0-9]+/ {print $1,$2}'`)

  TIME=`echo "$(sed -n 3p $i) * $(sed -n 7p $i)" | bc`

  CRATE=`echo "${TEMP[0]} - ${TEMP[1]} / $(sed -n 4p $i) * $(sed -n 6p $i)" | bc`

  echo "Temperature: ${TEMP[0]}"

  echo "Time: $TIME"

  echo "Cooling Rate: $CRATE"

done

I think that's what you wanted anyway.

frankie_DJ

10-04-2006 08:43 PM

OK thank you guys. Wow. I can't believe I lost all afternoon on this thing.

SOrry ghostdog, but I don't have time to deal with yet another language. Although from what you wrote python seems really powerfull.

Jonaskoelker, thanks for the script. It didn't work out of the box, since shell doesn't do arithmetics with real numbers, so I had to pipe to bc. Also the second use of IFS (IFS=',') doesn't really do what it's supposed to and I don't really know how to fix that.

Edit: Pete, thanks, I will see if your script works better. By the way, isn't it overkill to use awk and sed? I mean sed loads about 50K of memory and awk probably even more. Just curious.

pete1234

10-04-2006 08:51 PM

Quote:

Edit: Pete, thanks, I will see if your script works better. By the way, isn't it overkill to use awk and sed? I mean sed loads about 50K of memory and awk probably even more. Just curious.

You're welcome, and you're probably right. I'm sure you could do it with sed or awk alone. I wasn't really thinking about conserving. system resources.

##EDIT This seems to work with just sed:

Code:

#!/bin/bash -

#



for i in $(ls whatever); do

  TEMP=(`sed -n -e 's/,/ /p' $i`)

  TIME=`echo "$(sed -n 3p $i) * $(sed -n 7p $i)" | bc`

  CRATE=`echo "${TEMP[0]} - ${TEMP[1]} / $(sed -n 4p $i) * $(sed -n 6p $i)" | bc`

  echo "Temperature: ${TEMP[0]}"

  echo "Time: $TIME"

  echo "Cooling Rate: $CRATE"

done

ghostdog74

10-04-2006 09:36 PM

Quote:

Originally Posted by frankie_DJ

SOrry ghostdog, but I don't have time to deal with yet another language.

hey no need to say sorry, its just an alternative..

Quote:

Although from what you wrote python seems really powerfull.

it is.

frankie_DJ

10-04-2006 10:50 PM

Thanks guys, I spend half a day on this but it wasn't wasted - I learned tons. If someone sees this and has few minutes, I wouldn't mind a version with awk only.

Also, I was curious why switching IFS doesn't work in the first version.

makyo

10-04-2006 11:32 PM

Hi.

Here's the beginning of an awk version, untested because there was no live data posted that I saw. You may need to adjust the variables, and, of course, remove the "next" statement ... cheers, makyo

Code:

#!/bin/sh



# @(#) a1      Demonstrate slurping in a whole file.



FILE=${1-data1}



awk '

BEGIN  { FS = "[, \t\n]" ; RS = "" }

        {

        print "field " $1, $2, $3, $4, $5, $6, $7, $8, $9

        # No real data, skip computation

        next

        title = $1 ; number1 = $2 ; number2 = $3

        line2 = $4 ; line3 = $5 ; line4 = $6 ; line6 = $8

        print "Temperature:", number1

        print "Time:", line2 * line6

        print "Cooling rate:", (number1-number2) / ( line6*line4)



        }

END    {

        }' $FILE

Produces on the outline data:

Code:

% ./a1

field Title number1 number2 10000 12000 L 0.7 0.7 0.0

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