redirect output to compressed format (C)

Question

Is it possible to use fprintf in such a way that write data to a compressed file? For example:

fopen ("myfile.txt","w");

will write to a plain text file. So the file size grows very large.

Answer 1

You can use zlib to write data to a compressed stream.

gzFile fp;
fp = gzopen(NAME, "wb");
gzprintf(fp, "Hello, %s!\n", "world");
gzclose(fp);

Compile it like this:

gcc -Wall -Wextra -o zprog zprog.c -lz

Use zcat to print the contents of the file.

Answer 2

The minimally-invasive solution if you're on a system that has pipes would be to open a pipe to an external gzip process. That way you can use all the normal stdio output functions without having to replace everything with zlib calls.

Answer 3

On Linux, you could use the zlib library (and link it as -lz) and use its compressed streams