Communication system and computer readable storage medium

A non-transitory computer readable storage medium storing thereon a program that causes a computer to function as:

• a terminal authenticating unit that authenticates each communication terminal among a plurality of communication terminals based on a single user ID, and keeps the plurality of communication terminals logged into an information providing service;
• a generation instruction receiving unit that receives, from at least any communication terminal among the plurality of communication terminals, an instruction to generate a provider registration information including a plurality of pieces of provider information that indicate providers of respective pieces of data being displayed on each communication terminal among the plurality of communication terminals;
• a provider information acquiring unit that acquires, upon reception of the instruction to generate the provider registration information, a plurality of pieces of provider information that indicate providers of data being displayed on each communication terminal among the plurality of communication terminals;
• and
• a registration information generating unit that generates the provider registration information, including the plurality of pieces of provider information acquired by the provider information acquiring unit, in which terminal identification information of each communication terminal among the plurality of communication terminals and each piece among a plurality of pieces of provider information that indicate providers of data being displayed on each communication terminal among the plurality of communication terminals are associated with each other;
• a registration information storing unit that stores therein the provider registration information;
• a designation information receiving unit that receives, from at least any communication terminal among the plurality of communication terminals, designation information that designates the provider registration information;
• and
• a provider information transmitting unit that transmits each piece among the plurality of pieces of provider information to each communication terminal among the plurality of communication terminals so as to cause each communication terminal among the plurality of communication terminals to display data provided by a provider indicated by a plurality of pieces of provider information included in the provider registration information when the designation information receiving unit has received the designation information and if all communication terminals among a plurality of communication terminals identified by a plurality of pieces of terminal identification information associated with a plurality of pieces of provider information included in the provider registration information are logged in, and the provider information transmitting unit transmits, to all the plurality of communication terminal that are logged in, data that indicates provider information corresponding to terminal identification information of the communication terminal that is not logged in when the designation information receiving unit has received the designation information and if at least any communication terminal among the plurality of communication terminals is not logged in.