added information about bpf_asm to help

hcxdumptool.c

@@ -4554,17 +4554,20 @@ fprintf(stdout, "%s %s  (C) %s ZeroBeat\n"
 	"-L             : show INTERFACE list and terminate\n"
 	"-l             : show INTERFACE list (tabulator separated and greppable) and terminate\n"
 	"-I <INTERFACE> : show detailed information about INTERFACE and terminate\n"
-	"--bpf=<file>   : input Berkeley Packet Filter (BPF) code in tcpdump raw format\n"
-	"                  tcpdump high level syntax:\n"
+	"--bpf=<file>   : input Berkeley Packet Filter (BPF) code (maximum %d instructions) in tcpdump raw format\n"
+	"                  example: tcpdump high level syntax:\n"
 	"                   $ tcpdump -y IEEE802_11_RADIO wlan addr3 11:22:33:44:55:66 -ddd > filter.bpf\n"
 	"                   see man pcap-filter\n"
-	"                  bpfc low level syntax:\n"
-	"                   $ bpfc -f tcpdump -i filter.asm\n"
+	"                  eample: bpf_asm low level compiler\n"
+	"                   $ bpf_asm filter.asm | tr ',' '\n' > filter.bpf\n"
+	"                   see https://www.kernel.org/doc/html/latest/networking/filter.html\n"
+	"                  example: bpfc low level syntax:\n"
+	"                   $ bpfc -f tcpdump -i filter.asm > filter.bpf\n"
 	"                   see man bpfc\n"
 	"-h             : show this help\n"
 	"-v             : show version\n"
 	"\n",
-	eigenname, VERSION_TAG, VERSION_YEAR, eigenname, eigenname, TIMEHOLD / 1000000000ULL);
+	eigenname, VERSION_TAG, VERSION_YEAR, eigenname, eigenname, TIMEHOLD / 1000000000ULL, BPF_MAXINSNS);
 fprintf(stdout, "less common options:\n--------------------\n"
 	"--disable_beacon          : do not transmit BEACON frames\n"
 	"--disable_deauthentication: do not transmit DEAUTHENTICATION/DISASSOCIATION frames\n"