gzip.c

#include <stdio.h>
#include <stdlib.h>
#include <zlib.h>

#define BUF_SIZE 1024

int main(int argc, char **argv)
{
        int ret = Z_OK;
        z_stream strm;

        Byte *ibuf, *obuf;
        FILE *ifp = fopen("input.txt", "r");
        FILE *ofp = fopen("output.gz", "w");

        ibuf = (Byte *)calloc(BUF_SIZE, sizeof(Byte));
        obuf = (Byte *)calloc(BUF_SIZE, sizeof(Byte));
        fread(ibuf, BUF_SIZE, 1, ifp);

        strm.zalloc = Z_NULL;
        strm.zfree = Z_NULL;
        strm.opaque = Z_NULL;

        ret = deflateInit2(&strm, 6, Z_DEFLATED, 31, 8, Z_DEFAULT_STRATEGY);

        strm.next_in = ibuf;
        strm.avail_in = BUF_SIZE;
        strm.next_out = obuf;
        strm.avail_out = BUF_SIZE;

        ret = deflate(&strm, Z_FINISH);

        fwrite(obuf, strm.total_out, 1, ofp);

END:
        deflateEnd(&strm);
        fclose(ofp);
        fclose(ifp);

        return 0;
}
~

gcc gzip.c -lz