zlib gzread function error when read .gz file?

Question

like title, here is my code:

int decompress_one_file(char *infilename, char *outfilename)
{
    gzFile infile = gzopen(infilename, "rb");
    FILE *outfile = fopen(outfilename, "wb");
    if (!infile || !outfile) return -1;

    char buffer[128] = {NULL};
    int num_read = 0;
    num_read = gzread(infile, buffer, sizeof(buffer)); // crash here
    while (num_read > 0) {
        fwrite(buffer, 1, num_read, outfile);
    }

    gzclose(infile);
    fclose(outfile);
    return 0;
}

when my console-app run to gzread(), its crash, I don't know what type of error is this?. zlib version: 1.2.11

update compress function:

int compress_one_file(char *infilename, char *outfilename)
{
    FILE *infile = fopen(infilename, "rb");
    gzFile outfile = gzopen(outfilename, "wb");
    if (!infile || !outfile) return -1;

    char inbuffer[128] = {NULL};
    int num_read = 0;
    unsigned long total_read = 0, total_wrote = 0;
    while ((num_read = fread(inbuffer, 1, sizeof(inbuffer), infile)) > 0) {
        total_read += num_read;
        gzwrite(outfile, inbuffer, num_read);
    }
    fclose(infile);
    gzclose(outfile);
    return 0;
}

Error that shows up:

Anyone got an idea about this error?

Answer 1

I checked and it works fine at my workstation. May be here is a issue with gzipped file? Could you show a file that give a crash?

But in any case you have a infinity loop of fwrite:

int num_read = 0;
while ((num_read = gzread(infile, buffer, sizeof(buffer))) > 0) {
    while (num_read > 0) {
        num_read -= fwrite(buffer, 1, num_read, outfile);
    }   
}