How to read SMS using AT on an embedded system with limited memory?

I'm developing a piece of embedded software, which also communicates with a modem through the AT protocol. Now I want to read messages, but I have come across a problem with my memory capacity. It could be that there are multiple messages for me, and using the AT command set, I get them returned all at once. I do not have the memory capacity to store them all to process them (I only have 1KB or so). See the examples here: http://www.smssolutions.net/tutorials/gsm/receivesmsat/ I send `AT+CMGL="ALL"`. I then get back something like: ``` +CMGL: 1,"REC UNREAD","+31625012354",,"07/07/05,09:55:16+08" Test message 1 +CMGL: 2,"REC UNREAD","+31625012354",,"07/07/05,09:56:03+08" Test message 2 OK ``` The problem here is that the message can contain certain directives, which trigger certain actions, which might take a while to execute. During that time, the buffer for receiving data from the modem can (will) overflow. On the other hand, I do not have the memory capacity to first read ALL the messages into memory to prevent the buffer overflow, and then process them from memory. An alternative is reading a single message, with `AT+CMGR=2`, getting back just one message: ``` +CMGL: 2,"REC UNREAD","+31625012354",,"07/07/05,09:56:03+08" Test message 2 OK ``` However, for this to work, I need know the storage location (2 in the above example). My gut feeling tells me to first run `AT+CMGL`, parsing the data and only keeping the storage locations, then requesting and parsing (and deleting) them one by one with `AT+CMGR`. However, I would like to receive a second opinion. I'm not that experienced with AT nor with embedded software yet, so perhaps I'm overlooking something.