root@iZwz98r5jfsgx41dfymo6iZ:/usr/local/lib# sudo apt-get install php5.6-mbstring
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package php5.6-mbstring
E: Couldn't find any package by glob 'php5.6-mbstring'
E: Couldn't find any package by regex 'php5.6-mbstring'
but I excuse：sudo apt-get install php-mbstring
root@iZwz98r5jfsgx41dfymo6iZ:/usr/local/lib# sudo apt-get install php-mbstring
Reading package lists... Done
Building dependency tree
Reading state information... Done
php-mbstring is already the newest version (1:7.0+35ubuntu6.1).
The following packages were automatically installed and are no longer required:
linux-headers-4.4.0-87 linux-headers-4.4.0-87-generic linux-image-4.4.0-87-generic linux-image-extra-4.4.0-87-generic
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 4 not upgraded.
what wrong with this？
