Shell variable value disappears

splintercdo · 12-06-2011, 05:35 AM

Hey guys,

As I understand now I have 2 row variables one global for script second local for loop.

How do I assign value from local row to global, basically, how to get value of local variable row out of cycle?

Code:

Code:

x=0; row="blabla"; wget -q "http://www.linuxquestions.org/" -O - | grep ".lqconsulting." | cut -d/ -f3 | cut -d. -f2 | while read row && [ $x -lt 1 ]; do x=$(( x=$x + 1  )); echo "1. $row"; done; echo "2. $row";

Result:
1. lqconsulting
2. blabla

catkin · 12-06-2011, 06:49 AM

Not sure why you want the loop, given that it only executes once, but this may be what you are looking for:

Code:

#!/bin/bash

while read row
do 
    echo "1. $row"
    break
done < <( wget -q "http://www.linuxquestions.org/" -O - | grep ".lqconsulting." | cut -d/ -f3 | cut -d. -f2 )

The technique is called process substitution.

David the H. · 12-06-2011, 02:06 PM

Your main question is explained here:

http://mywiki.wooledge.org/BashFAQ/024

But more than that, I can't quite understand what the command is supposed to do. The whole logic seems off to me.

Are you just trying to add a number prefix to each of the found instances? If that's the case it would probably be better to simply save the results to an array and use a separate loop to do the print work.

Code:

lqarray=( $(wget -q "http://www.linuxquestions.org/" -O - | grep ".lqconsulting." | cut -d/ -f3 | cut -d. -f2 ) )

i=1
for text in "${lqarray[@]}"; do
	echo "$i. $text"
	(( i++ ))
done

There are probably also cleaner ways to extract the text you want than chaining multiple grep and cut commands, if I knew exactly what text you were trying to match.

Could you please explain what your real goal is, so we can help you to come up with a cleaner solution?