i am using sim900 gps/gprs module shield connected to an Arduino Uno, how will i be able to parse the response of my AT commands? Or how will i be able to remove the 1st lin
The first line AT+CMGL="ALL" seems to be the echo. You can disable it by sending ATE0 to your module in your setup function.
AT+CMGL="ALL"
ATE0
setup
As for the rest of the data, it all have the same format. You can easily write your parser using different string manipulation functions.