view miscutil/fc-pulse-rts.c @ 965:2969032bdfac

fcup-smsend[mult]: fix buglet in K&R C NULL pointer passing The only 100% safe way to pass a NULL pointer as a function argument in K&R C is to cast 0 to a pointer type; failing to do so may cause mysterious bugs (invalid stack frames or garbage in argument registers) on 64-bit machines. This issue has already been fixed in most of FC host tools, but I just found some missed spots: passing of NULL UDH to PDU encoding functions in fcup-smsend[mult] in the case of single (not concatenated) SMS.
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 01 Sep 2023 07:33:51 +0000
parents 5b8287c655cf
children
line wrap: on
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/*
 * This utility opens a serial port, asserts RTS for 50 ms, then negates it
 * and exits.  It is intended for use with FreeCalypso DUART28C adapters.
 */

#include <sys/types.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

main(argc, argv)
	char **argv;
{
	int target_fd;
	int mctl_arg = TIOCM_RTS;

	if (argc != 2) {
		fprintf(stderr, "usage: %s ttyname\n", argv[0]);
		exit(1);
	}
	target_fd = open(argv[1], O_RDWR|O_NONBLOCK);
	if (target_fd < 0) {
		perror(argv[1]);
		exit(1);
	}
	ioctl(target_fd, TIOCMBIS, &mctl_arg);
	usleep(50000);
	ioctl(target_fd, TIOCMBIC, &mctl_arg);
	exit(0);
}