Extrait la valeur entre "[et]" à l'aide du script shell

echo '"[""sometext1"", ""sometext2"", ""sometext3""]"'|cut -d "[" -f2 | cut -d "]" -f1

Échappez au premier '['

echo '"[""sometext1"", ""sometext2"", ""sometext3""]"'|
   sed -r 's/"\[(.*)]"/\1/'

Utilisation de Perl

$ echo '"[""sometext1"", ""sometext2"", ""sometext3""]"'
"[""sometext1"", ""sometext2"", ""sometext3""]"

$ echo '"[""sometext1"", ""sometext2"", ""sometext3""]"' | perl -ne ' m/\[(.*)\]/ and print $1 '
""sometext1"", ""sometext2"", ""sometext3""
$