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src/Source/ZLib/gzread.c  view on Meta::CPAN

    if (file == NULL)
        return -1;
    state = (gz_statep)file;

    /* check that we're reading and that there's no (serious) error */
    if (state->mode != GZ_READ ||
        (state->err != Z_OK && state->err != Z_BUF_ERROR))
        return -1;

    /* process a skip request */
    if (state->seek) {
        state->seek = 0;
        if (gz_skip(state, state->skip) == -1)
            return -1;
    }

    /* can't push EOF */
    if (c < 0)
        return -1;

    /* if output buffer empty, put byte at end (allows more pushing) */
    if (state->x.have == 0) {
        state->x.have = 1;
        state->x.next = state->out + (state->size << 1) - 1;
        state->x.next[0] = c;
        state->x.pos--;
        state->past = 0;
        return c;
    }

    /* if no room, give up (must have already done a gzungetc()) */
    if (state->x.have == (state->size << 1)) {
        gz_error(state, Z_DATA_ERROR, "out of room to push characters");
        return -1;
    }

    /* slide output data if needed and insert byte before existing data */
    if (state->x.next == state->out) {
        unsigned char *src = state->out + state->x.have;
        unsigned char *dest = state->out + (state->size << 1);
        while (src > state->out)
            *--dest = *--src;
        state->x.next = dest;
    }
    state->x.have++;
    state->x.next--;
    state->x.next[0] = c;
    state->x.pos--;
    state->past = 0;
    return c;
}

/* -- see zlib.h -- */
char * ZEXPORT gzgets(file, buf, len)
    gzFile file;
    char *buf;
    int len;
{
    unsigned left, n;
    char *str;
    unsigned char *eol;
    gz_statep state;

    /* check parameters and get internal structure */
    if (file == NULL || buf == NULL || len < 1)
        return NULL;
    state = (gz_statep)file;

    /* check that we're reading and that there's no (serious) error */
    if (state->mode != GZ_READ ||
        (state->err != Z_OK && state->err != Z_BUF_ERROR))
        return NULL;

    /* process a skip request */
    if (state->seek) {
        state->seek = 0;
        if (gz_skip(state, state->skip) == -1)
            return NULL;
    }

    /* copy output bytes up to new line or len - 1, whichever comes first --
       append a terminating zero to the string (we don't check for a zero in
       the contents, let the user worry about that) */
    str = buf;
    left = (unsigned)len - 1;
    if (left) do {
        /* assure that something is in the output buffer */
        if (state->x.have == 0 && gz_fetch(state) == -1)
            return NULL;                /* error */
        if (state->x.have == 0) {       /* end of file */
            state->past = 1;            /* read past end */
            break;                      /* return what we have */
        }

        /* look for end-of-line in current output buffer */
        n = state->x.have > left ? left : state->x.have;
        eol = (unsigned char *)memchr(state->x.next, '\n', n);
        if (eol != NULL)
            n = (unsigned)(eol - state->x.next) + 1;

        /* copy through end-of-line, or remainder if not found */
        memcpy(buf, state->x.next, n);
        state->x.have -= n;
        state->x.next += n;
        state->x.pos += n;
        left -= n;
        buf += n;
    } while (left && eol == NULL);

    /* return terminated string, or if nothing, end of file */
    if (buf == str)
        return NULL;
    buf[0] = 0;
    return str;
}

/* -- see zlib.h -- */
int ZEXPORT gzdirect(file)
    gzFile file;
{
    gz_statep state;

    /* get internal structure */
    if (file == NULL)
        return 0;
    state = (gz_statep)file;

    /* if the state is not known, but we can find out, then do so (this is
       mainly for right after a gzopen() or gzdopen()) */
    if (state->mode == GZ_READ && state->how == LOOK && state->x.have == 0)
        (void)gz_look(state);

    /* return 1 if transparent, 0 if processing a gzip stream */
    return state->direct;
}

/* -- see zlib.h -- */
int ZEXPORT gzclose_r(file)
    gzFile file;
{
    int ret, err;
    gz_statep state;

    /* get internal structure */
    if (file == NULL)
        return Z_STREAM_ERROR;
    state = (gz_statep)file;

    /* check that we're reading */
    if (state->mode != GZ_READ)
        return Z_STREAM_ERROR;

    /* free memory and close file */
    if (state->size) {
        inflateEnd(&(state->strm));
        free(state->out);
        free(state->in);
    }
    err = state->err == Z_BUF_ERROR ? Z_BUF_ERROR : Z_OK;
    gz_error(state, Z_OK, NULL);
    free(state->path);
    ret = close(state->fd);
    free(state);
    return ret ? Z_ERRNO : err;
}