fd = open(pktfilename, O_WRONLY|O_CREAT, 0644); write(fd, pkt.data, pkt.size); close(fd);
if (!nowrite) { fd = open(pktfilename, O_WRONLY|O_CREAT, 0644); write(fd, pkt.data, pkt.size); close(fd); }
int main(int argc, char **argv){    char fntemplate[PATH_MAX];    char pktfilename[PATH_MAX];    AVFormatContext *fctx;    AVPacket pkt;    int64_t pktnum = 0;    int64_t maxpkts = 0;    int err;        if (argc < 2)        return usage(1);    if (argc > 2)        maxpkts = atoi(argv[2]);    strncpy(fntemplate, argv[1], PATH_MAX-1);    if (strrchr(argv[1], '/'))        strncpy(fntemplate, strrchr(argv[1], '/')+1, PATH_MAX-1);    if (strrchr(fntemplate, '.'))        *strrchr(fntemplate, '.') = '\0';    if (strchr(fntemplate, '%')) {        fprintf(stderr, "can't use filenames containing '%%'\n");        return usage(1);    }    if (strlen(fntemplate) + sizeof(PKTFILESUFF) >= PATH_MAX-1) {        fprintf(stderr, "filename too long\n");        return usage(1);    }    strcat(fntemplate, PKTFILESUFF);    printf("FNTEMPLATE: '%s'\n", fntemplate);        // register all file formats    av_register_all();        err = av_open_input_file(&fctx, argv[1], NULL, 0, NULL);    if (err < 0) {        fprintf(stderr, "av_open_input_file: error %d\n", err);        return 1;    }        err = av_find_stream_info(fctx);    if (err < 0) {        fprintf(stderr, "av_find_stream_info: error %d\n", err);        return 1;    }        av_init_packet(&pkt);        while ((err = av_read_frame(fctx, &pkt)) >= 0) {        int fd;        snprintf(pktfilename, PATH_MAX-1, fntemplate, pktnum, pkt.stream_index, pkt.pts, pkt.size, (pkt.flags & PKT_FLAG_KEY)?'K':'_');        printf(PKTFILESUFF"\n", pktnum, pkt.stream_index, pkt.pts, pkt.size, (pkt.flags & PKT_FLAG_KEY)?'K':'_');        //printf("open(\"%s\")\n", pktfilename);        fd = open(pktfilename, O_WRONLY|O_CREAT, 0644);        write(fd, pkt.data, pkt.size);        close(fd);        pktnum++;        if (maxpkts && (pktnum >= maxpkts))            break;    }        return 0;}