From: Ben Bacarisse on
Chimu <echimu(a)> writes:

> I got data in $x separated by :, further each field has 4 values and i
> want get those. So i come with IFS and read code
> Input
> x="tab1,c,1,3,db1:tab2,d,21,13,db45:tab12,t,11,16,db4"
> output
> Data feed: tab1 c 1 3 db1
> Data feed: tab2 d 21 13 db45
> Data feed: ab12 t 11 16 db4
> my code so far
> ~~~~~~~~~~
> while IFS=: read -r field
> do
> while IFS=, read -r a b c d
> do
> echo "Data feed: $a $b $c $d"
> done <<<"$field"
> #IFS=:
> done <<<$x
> ~~~~~~~~~~
> so far it is not working and i'm not able to pull data. i don't wanna
> use external tool just bash builtin and IFS. any thoughts on how to
> fix this? are you allowed to use multiple IFS? btw, I'm using bash 3.x
> on Debian Linux server.

read will read a line and you have only one line of input so there is
nothing to loop over in the outer loop. The other problem you are
seeing is that 'field' and 'd' both get set to the remaining words and
separators which is not what you want. Also, the inner loop is not
really serving any purpose.

There a lots of ways to do this, but the one that is closest to your
original is probably:

echo "$x:" | while read -r -d: field
IFS=, read -r a b c d rest <<<"$field"
echo "Data feed: $a $b $c $d"

The -d flag causes the while/read loop to see multiple "lines". The
echo adds a terminating separator so that the last "line" is seen.
The rest variable in the inner read collects anything left over after
the parts you want.