I am trying to implement the zlib.h deflate and inflate functions to compress and decompress a char array (not a file).
I would like to know if the following syntax is correct ? Am I missing something or defined something incorrectly ?
char a[50] = "Hello World!";
char b[50];
char c[50];
// deflate
// zlib struct
z_stream defstream;
defstream.zalloc = Z_NULL;
defstream.zfree = Z_NULL;
defstream.opaque = Z_NULL;
defstream.avail_in = (uInt)sizeof(a); // size of input
defstream.next_in = (Bytef *)a; // input char array
defstream.avail_out = (uInt)sizeof(b); // size of output
defstream.next_out = (Bytef *)b; // output char array
deflateInit(&defstream, Z_DEFAULT_COMPRESSION);
deflate(&defstream, Z_FINISH);
deflateEnd(&defstream);
printf("Deflate:\n%lu\n%s\n", strlen(b), b);
// inflate
// zlib struct
z_stream infstream;
infstream.zalloc = Z_NULL;
infstream.zfree = Z_NULL;
infstream.opaque = Z_NULL;
infstream.avail_in = (uInt)sizeof(b); // size of input
infstream.next_in = (Bytef *)b; // input char array
infstream.avail_out = (uInt)sizeof(c); // size of output
infstream.next_out = (Bytef *)c; // output char array
inflateInit(&infstream);
inflate(&infstream, Z_NO_FLUSH);
inflateEnd(&infstream);
printf("Inflate:\n%lu\n%s\n", strlen(c), c);
zlib already has a simple inflate/deflate function you can use.
char a[50] = "Hello, world!";
char b[50];
char c[50];
uLong ucompSize = strlen(a)+1; // "Hello, world!" + NULL delimiter.
uLong compSize = compressBound(ucompSize);
// Deflate
compress((Bytef *)b, &compSize, (Bytef *)a, ucompSize);
// Inflate
uncompress((Bytef *)c, &ucompSize, (Bytef *)b, compSize);
When in doubt, check out the zlib manual. My code is crappy, sorry =/