Shell Programming and Scripting

to start with......

Code:

while read COLUNA LINHA
do
    echo "COLUNA : $COLUNA "
    echo "LINHA : $LINHA"
    convert -fill red -draw "text $COLUNA ,$LINHA '*'" mapa.gif teste.gif
done < below

Try this:

Code:

{
while read COLUMN LINE COUNT
do
    if [[ ${COLUMN} != +([0-9]) || ${LINE} != +([0-9]) ]]; then
       continue
    fi

    echo "COLUNA : ${COLUMN}"
    echo "LINHA : ${LINE}"
    convert -fill red -draw 'text ${COLUMN},${LINE} "*"' mapa.gif teste.gif 

done < file.dat 2> /dev/null
}

Whoops, I didn't really try to validate the convert command so you better look at vgersh99's example as well. The double quotes are necessary.

tmarikle,
you need double-quotes in order to have the shell expand the 'read-in' vars - COLUNA and LINHA.

I don't know much of the 'convert' myself......

Dear all:

the variable passing to convert is a little tricky, and i could solve the problem in convert with

convert -fill red -draw "text $LINHA,$COLUNA *" mapa.gif mapa.gif

As you've probably noticed, the code was wrong at the stage of invoking convert: i need to accumulate my data points...so the file always remains the same (mapa.gif).

The actual problem now resides on reading only the the pairs COLUNA, LINHA, on my table...since the script reads all the columns in the same line, as depicted on this simple output:

COLUNA : 1632
LINHA : 531 41.132 -8.397 52.000
convert: Non-conforming drawing primitive definition `text'.

For the time being, the code is:

#!/bin/bash

TIMESTAMP=`date "+%d%m%Y%H%M"`

cp map.gif mapa.gif


while read COLUNA LINHA
do
echo "COLUNA : $COLUNA"
echo "LINHA : $LINHA"
convert -fill red -draw "text $LINHA,$COLUNA *" mapa.gif mapa.gif
done < below

And the contents of file "below" is:
TOTAL DE PIXELS COM VALORES ABAIXO DO LIMIAR (9) : 261


COLUNA LINHA LATITUDE LONGITUDE COUNT :

1632 531 41.132 -8.397 52.000
1641 617 37.643 -7.611 52.000
1651 604 38.146 -7.311 52.000
1651 605 38.107 -7.307 52.000


Thank you all for your precious help and comments.

That's what I was attempting to say but maybe it wasn't clear. I only noticed the single quotes after your previous post. I was just partially being too lazy to edit the post and partially trying to prompt the OP to read your correction on that particular line.

That is because read needs to know how many things to read. If you specify while read COLUMN LINE JUNK then columns 3 through the end of the line will be dumped into read variable JUNK.