read command help in bash

I wanted to read output of a command in an array:

Something like:

(reformatted for code using {} above the input box)

var=`echo tell told till`
echo "$var" | while read temp; do echo $temp ; done  

This program will output:

tell 
told 
till

I had two questions:

1. Read command reads from stdin. But in the above case how is it reading? echo puts the values on stdout.
2. I wanted to know how to put those elements in an array? Basically how to put elements in stdout in an array. Read -a command can put the e开发者_如何学JAVAlements in stdin, but i wanted stdout.

If you want to put elements from stdout into array, eg

declare -a array
array=( $(my command that generates stdout) ) #eg array=( $(ls))

If you have a variable and want to put into array

$> var="tell till told"
$> read -a array <<< $var
$> echo ${array[1]}
till
$> echo ${array[0]}
tell

OR just

array=($var)

From bash reference:

   Here Strings
       A variant of here documents, the format is:

              <<<word

       The word is expanded and supplied to the command on its standard input.

A pipe ("|") connects the preceding command's stdout to the following command's stdin.

To split a string into words you can simply use:

for word in $string;
do 
    echo $word;
done;

So to do what you're asking

while read line
do
    for word in $line
    do
        echo $word
    done
done

And as Ignacio Vazquez-Abrams said, a pipe connects the left side's stdout to the right side's stdin.

When you use a pipe:

command1 | command2

The output of command1, written to the stdout, will be the input for command2 (stdin). The pipe "transforms" stdout to stdin.

And for the array: You give values to the array whith:

array=(val1 val2 val3)

So just try it:

array=($var)

You've got now $var in $array:

> echo ${array[*]}
tell
told
till

> echo ${array[1]}
told

Is this what you mean?