Programming

I am writing a C program to get messages from a JMS queue into a string variable and then write them to a database.

The messages are compressed (gzip) and encoded (base64), so I need to be able to perform gunzip and base64 decode inside the C. I don't want to write any of the messages to file so i need to work on the string.

Is this possible?

if it is base 64 i would guess to declare the string a variable you would use a double precision float and use the ascii code to convert the number to characters.. and use system() to gunzip the string. it sounds easy it should be simple to define a max number of characters for the string and memalloc the string into a buffer. then transfer it to the database using strncat.. i think you are just making matters a little complex with your script which is easy to do in C.. just keep it simple..
moxxx68
hope that answers your question..

You don't need to write to a file to use an external utility. You can use a pipe to make the utility process the data incrementally. See popen(3). If using gzip(1), be you gotta be careful about deadlocks here (check with select(2) if gzip needs to input or output or else the 2 processes might end up waiting on each other). If the thing is that you do not want to fork()+exec() because there are A LOT of JMS messages and that would be too slow, then AFAIK zlib(3) can be used to decompress gzip output and you can find tons of base64 C code on the web.