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74510d4b
ML		 1/*
2 * This file is part of the libserialport project.
3 *
4 * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
5 * Copyright (C) 2010-2012 Uwe Hermann <uwe@hermann-uwe.de>
6 * Copyright (C) 2013 Martin Ling <martin-libserialport@earth.li>
7 *
8 * This program is free software: you can redistribute it and/or modify
9 * it under the terms of the GNU Lesser General Public License as
10 * published by the Free Software Foundation, either version 3 of the
11 * License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public License
19 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22#include <string.h>
23#include <sys/types.h>
24#include <sys/stat.h>
25#include <fcntl.h>
26#include <unistd.h>
3b63f34d
ML		 27#include <stdlib.h>
28#include <errno.h>
74510d4b
ML		 29#ifdef _WIN32
30#include <windows.h>
3b63f34d 31#include <tchar.h>
74510d4b 32#else
74510d4b
ML		 33#include <termios.h>
34#include <sys/ioctl.h>
35#endif
3b63f34d 36#ifdef __APPLE__
1ebf4347
ML		 37#include <IOKit/IOKitLib.h>
38#include <IOKit/serial/IOSerialKeys.h>
39#include <sys/syslimits.h>
3b63f34d
ML		 40#endif
41#ifdef __linux__
42#include "libudev.h"
4b97c9fc 43#include "linux/serial.h"
3b63f34d 44#endif
74510d4b
ML		 45
46#include "serialport.h"
47
d54e9004
ML		 48static struct sp_port *sp_port_new(char *portname, size_t len)
49{
50 struct sp_port *port;
51
52 if (!(port = malloc(sizeof(struct sp_port))))
53 return NULL;
54
55 if (!(port->name = malloc(len)))
56 {
57 free(port);
58 return NULL;
59 }
60
61 memcpy(port->name, portname, len);
62
63 return port;
64}
65
66static struct sp_port **sp_list_append(struct sp_port **list, char *portname, size_t len)
3b63f34d
ML		 67{
68 void *tmp;
69 unsigned int count;
70 for (count = 0; list[count]; count++);
d54e9004 71 if (!(tmp = realloc(list, sizeof(struct sp_port *) * (count + 2))))
3b63f34d
ML		 72 goto fail;
73 list = tmp;
d54e9004 74 if (!(list[count] = sp_port_new(portname, len)))
3b63f34d 75 goto fail;
db2794ce 76 list[count + 1] = NULL;
3b63f34d
ML		 77 return list;
78fail:
79 sp_free_port_list(list);
80 return NULL;
81}
82
68ab64cc
ML		 83/**
84 * List the serial ports available on the system.
85 *
86 * @return A null-terminated array of port name strings.
87 */
d54e9004 88struct sp_port **sp_list_ports(void)
3b63f34d 89{
d54e9004 90 struct sp_port **list;
24c1a4bb 91
d54e9004 92 if (!(list = malloc(sizeof(struct sp_port **))))
24c1a4bb
ML		 93 return NULL;
94
95 list[0] = NULL;
3b63f34d
ML		 96
97#ifdef _WIN32
98 HKEY key;
bdfb5b8c
ML		 99 TCHAR *value, *data;
100 DWORD max_value_len, max_data_size, max_data_len;
101 DWORD value_len, data_size, data_len;
3b63f34d
ML		 102 DWORD type, index = 0;
103
104 if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, _T("HARDWARE\\DEVICEMAP\\SERIALCOMM"),
105 0, KEY_QUERY_VALUE, &key) != ERROR_SUCCESS)
106 return NULL;
107 if (RegQueryInfoKey(key, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
bdfb5b8c 108 &max_value_len, &max_data_size, NULL, NULL) != ERROR_SUCCESS)
3b63f34d
ML		 109 goto out_close;
110 max_data_len = max_data_size / sizeof(TCHAR);
bdfb5b8c 111 if (!(value = malloc((max_value_len + 1) * sizeof(TCHAR))))
3b63f34d
ML		 112 goto out_close;
113 if (!(data = malloc((max_data_len + 1) * sizeof(TCHAR))))
bdfb5b8c 114 goto out_free_value;
3b63f34d 115 while (
bdfb5b8c 116 value_len = max_value_len,
3b63f34d 117 data_size = max_data_size,
bdfb5b8c 118 RegEnumValue(key, index, value, &value_len,
3b63f34d
ML		 119 NULL, &type, (LPBYTE)data, &data_size) == ERROR_SUCCESS)
120 {
121 data_len = data_size / sizeof(TCHAR);
122 data[data_len] = '\0';
123 if (type == REG_SZ)
124 if (!(list = sp_list_append(list,
125 data, (data_len + 1) * sizeof(TCHAR))))
126 goto out;
127 index++;
128 }
129out:
130 free(data);
bdfb5b8c
ML		 131out_free_value:
132 free(value);
3b63f34d
ML		 133out_close:
134 RegCloseKey(key);
135 return list;
136#endif
137#ifdef __APPLE__
138 mach_port_t master;
139 CFMutableDictionaryRef classes;
140 io_iterator_t iter;
141 char *path;
142 io_object_t port;
143 CFTypeRef cf_path;
144 Boolean result;
145
146 if (IOMasterPort(MACH_PORT_NULL, &master) != KERN_SUCCESS)
147 return NULL;
148
149 if (!(classes = IOServiceMatching(kIOSerialBSDServiceValue)))
150 return NULL;
151
152 CFDictionarySetValue(classes,
153 CFSTR(kIOSerialBSDTypeKey), CFSTR(kIOSerialBSDAllTypes));
154
155 if (!(IOServiceGetMatchingServices(master, classes, &iter)))
156 return NULL;
157
158 if (!(path = malloc(PATH_MAX)))
159 goto out_release;
160
1ebf4347 161 while ((port = IOIteratorNext(iter))) {
3b63f34d
ML		 162 cf_path = IORegistryEntryCreateCFProperty(port,
163 CFSTR(kIOCalloutDeviceKey), kCFAllocatorDefault, 0);
164 if (cf_path) {
165 result = CFStringGetCString(cf_path,
166 path, PATH_MAX, kCFStringEncodingASCII);
167 CFRelease(cf_path);
168 if (result)
169 if (!(list = sp_list_append(list, path, strlen(path) + 1)))
170 {
171 IOObjectRelease(port);
172 goto out;
173 }
174 }
175 IOObjectRelease(port);
176 }
177
178out:
179 free(path);
180out_release:
181 IOObjectRelease(iter);
182 return list;
183#endif
184#ifdef __linux__
185 struct udev *ud;
186 struct udev_enumerate *ud_enumerate;
187 struct udev_list_entry *ud_list;
188 struct udev_list_entry *ud_entry;
189 const char *path;
08fe0bdb 190 struct udev_device *ud_dev, *ud_parent;
3b63f34d 191 const char *name;
4b97c9fc
ML		 192 const char *driver;
193 int fd, ioctl_result;
194 struct serial_struct serial_info;
3b63f34d
ML		 195
196 ud = udev_new();
197 ud_enumerate = udev_enumerate_new(ud);
198 udev_enumerate_add_match_subsystem(ud_enumerate, "tty");
199 udev_enumerate_scan_devices(ud_enumerate);
200 ud_list = udev_enumerate_get_list_entry(ud_enumerate);
3b63f34d
ML		 201 udev_list_entry_foreach(ud_entry, ud_list)
202 {
203 path = udev_list_entry_get_name(ud_entry);
204 ud_dev = udev_device_new_from_syspath(ud, path);
08fe0bdb
ML		 205 /* If there is no parent device, this is a virtual tty. */
206 ud_parent = udev_device_get_parent(ud_dev);
207 if (ud_parent == NULL)
208 {
209 udev_device_unref(ud_dev);
210 continue;
211 }
3b63f34d 212 name = udev_device_get_devnode(ud_dev);
4b97c9fc
ML		 213 /* The serial8250 driver has a hardcoded number of ports.
214 * The only way to tell which actually exist on a given system
215 * is to try to open them and make an ioctl call. */
216 driver = udev_device_get_driver(ud_parent);
217 if (driver && !strcmp(driver, "serial8250"))
218 {
219 if ((fd = open(name, O_RDWR | O_NONBLOCK | O_NOCTTY)) < 0)
220 goto skip;
221 ioctl_result = ioctl(fd, TIOCGSERIAL, &serial_info);
222 close(fd);
223 if (ioctl_result != 0)
224 goto skip;
225 if (serial_info.type == PORT_UNKNOWN)
226 goto skip;
227 }
3b63f34d 228 list = sp_list_append(list, (void *)name, strlen(name) + 1);
4b97c9fc 229skip:
3b63f34d
ML		 230 udev_device_unref(ud_dev);
231 if (!list)
232 goto out;
233 }
234out:
235 udev_enumerate_unref(ud_enumerate);
236 udev_unref(ud);
237 return list;
238#endif
239}
240
68ab64cc
ML		 241/**
242 * Free a port list returned by sp_list_ports.
243 */
d54e9004 244void sp_free_port_list(struct sp_port **list)
3b63f34d
ML		 245{
246 unsigned int i;
247 for (i = 0; list[i]; i++)
248 free(list[i]);
249 free(list);
250}
251
74510d4b
ML		 252static int sp_validate_port(struct sp_port *port)
253{
254 if (port == NULL)
255 return 0;
256#ifdef _WIN32
257 if (port->hdl == INVALID_HANDLE_VALUE)
258 return 0;
259#else
260 if (port->fd < 0)
261 return 0;
262#endif
263 return 1;
264}
265
266#define CHECK_PORT() do { if (!sp_validate_port(port)) return SP_ERR_ARG; } while (0)
267
268/**
269 * Open the specified serial port.
270 *
271 * @param port Pointer to empty port structure allocated by caller.
272 * @param portname Name of port to open.
273 * @param flags Flags to use when opening the serial port. Possible flags
274 * are: SP_MODE_RDWR, SP_MODE_RDONLY, SP_MODE_NONBLOCK.
275 *
276 * @return SP_OK on success, SP_ERR_FAIL on failure,
277 * or SP_ERR_ARG if an invalid port or name is passed.
278 */
d54e9004 279int sp_open(struct sp_port *port, int flags)
74510d4b
ML		 280{
281 if (!port)
282 return SP_ERR_ARG;
283
74510d4b
ML		 284#ifdef _WIN32
285 DWORD desired_access = 0, flags_and_attributes = 0;
286 /* Map 'flags' to the OS-specific settings. */
287 desired_access |= GENERIC_READ;
288 flags_and_attributes = FILE_ATTRIBUTE_NORMAL;
289 if (flags & SP_MODE_RDWR)
290 desired_access |= GENERIC_WRITE;
291 if (flags & SP_MODE_NONBLOCK)
292 flags_and_attributes |= FILE_FLAG_OVERLAPPED;
293
294 port->hdl = CreateFile(port->name, desired_access, 0, 0,
295 OPEN_EXISTING, flags_and_attributes, 0);
296 if (port->hdl == INVALID_HANDLE_VALUE)
297 return SP_ERR_FAIL;
298#else
299 int flags_local = 0;
300 /* Map 'flags' to the OS-specific settings. */
301 if (flags & SP_MODE_RDWR)
302 flags_local |= O_RDWR;
303 if (flags & SP_MODE_RDONLY)
304 flags_local |= O_RDONLY;
305 if (flags & SP_MODE_NONBLOCK)
306 flags_local |= O_NONBLOCK;
307
308 if ((port->fd = open(port->name, flags_local)) < 0)
309 return SP_ERR_FAIL;
310#endif
311
312 return SP_OK;
313}
314
315/**
316 * Close the specified serial port.
317 *
318 * @param port Pointer to port structure.
319 *
320 * @return SP_OK on success, SP_ERR_FAIL on failure,
321 * or SP_ERR_ARG if an invalid port is passed.
322 */
323int sp_close(struct sp_port *port)
324{
325 CHECK_PORT();
326
327#ifdef _WIN32
328 /* Returns non-zero upon success, 0 upon failure. */
329 if (CloseHandle(port->hdl) == 0)
330 return SP_ERR_FAIL;
331#else
332 /* Returns 0 upon success, -1 upon failure. */
333 if (close(port->fd) == -1)
334 return SP_ERR_FAIL;
335#endif
336
337 return SP_OK;
338}
339
340/**
341 * Flush serial port buffers.
342 *
343 * @param port Pointer to port structure.
344 *
345 * @return SP_OK on success, SP_ERR_FAIL on failure,
346 * or SP_ERR_ARG if an invalid port is passed.
347 */
348int sp_flush(struct sp_port *port)
349{
350 CHECK_PORT();
351
352#ifdef _WIN32
353 /* Returns non-zero upon success, 0 upon failure. */
354 if (PurgeComm(port->hdl, PURGE_RXCLEAR | PURGE_TXCLEAR) == 0)
355 return SP_ERR_FAIL;
356#else
357 /* Returns 0 upon success, -1 upon failure. */
358 if (tcflush(port->fd, TCIOFLUSH) < 0)
359 return SP_ERR_FAIL;
360#endif
361 return SP_OK;
362}
363
364/**
365 * Write a number of bytes to the specified serial port.
366 *
367 * @param port Pointer to port structure.
368 * @param buf Buffer containing the bytes to write.
369 * @param count Number of bytes to write.
370 *
371 * @return The number of bytes written, SP_ERR_FAIL on failure,
372 * or SP_ERR_ARG if an invalid port is passed.
373 */
374int sp_write(struct sp_port *port, const void *buf, size_t count)
375{
376 CHECK_PORT();
377
378 if (!buf)
379 return SP_ERR_ARG;
380
381#ifdef _WIN32
382 DWORD written = 0;
383 /* Returns non-zero upon success, 0 upon failure. */
384 if (WriteFile(port->hdl, buf, count, &written, NULL) == 0)
385 return SP_ERR_FAIL;
386 return written;
387#else
388 /* Returns the number of bytes written, or -1 upon failure. */
389 ssize_t written = write(port->fd, buf, count);
390 if (written < 0)
391 return SP_ERR_FAIL;
392 else
393 return written;;
394#endif
395}
396
397/**
398 * Read a number of bytes from the specified serial port.
399 *
400 * @param port Pointer to port structure.
401 * @param buf Buffer where to store the bytes that are read.
402 * @param count The number of bytes to read.
403 *
404 * @return The number of bytes read, SP_ERR_FAIL on failure,
405 * or SP_ERR_ARG if an invalid port is passed.
406 */
407int sp_read(struct sp_port *port, void *buf, size_t count)
408{
409 CHECK_PORT();
410
411 if (!buf)
412 return SP_ERR_ARG;
413
414#ifdef _WIN32
415 DWORD bytes_read = 0;
416 /* Returns non-zero upon success, 0 upon failure. */
417 if (ReadFile(port->hdl, buf, count, &bytes_read, NULL) == 0)
418 return SP_ERR_FAIL;
419 return bytes_read;
420#else
421 ssize_t bytes_read;
422 /* Returns the number of bytes read, or -1 upon failure. */
423 if ((bytes_read = read(port->fd, buf, count)) < 0)
424 return SP_ERR_FAIL;
425 return bytes_read;
426#endif
427}
428
429/**
430 * Set serial parameters for the specified serial port.
431 *
432 * @param port Pointer to port structure.
433 * @param baudrate The baudrate to set.
434 * @param bits The number of data bits to use.
435 * @param parity The parity setting to use (0 = none, 1 = even, 2 = odd).
436 * @param stopbits The number of stop bits to use (1 or 2).
437 * @param flowcontrol The flow control settings to use (0 = none, 1 = RTS/CTS,
438 * 2 = XON/XOFF).
439 *
440 * @return The number of bytes read, SP_ERR_FAIL on failure,
441 * or SP_ERR_ARG if an invalid argument is passed.
442 */
443int sp_set_params(struct sp_port *port, int baudrate,
444 int bits, int parity, int stopbits,
445 int flowcontrol, int rts, int dtr)
446{
447 CHECK_PORT();
448
449#ifdef _WIN32
450 DCB dcb;
451
452 if (!GetCommState(port->hdl, &dcb))
453 return SP_ERR_FAIL;
454
455 switch (baudrate) {
456 /*
457 * The baudrates 50/75/134/150/200/1800/230400/460800 do not seem to
458 * have documented CBR_* macros.
459 */
460 case 110:
461 dcb.BaudRate = CBR_110;
462 break;
463 case 300:
464 dcb.BaudRate = CBR_300;
465 break;
466 case 600:
467 dcb.BaudRate = CBR_600;
468 break;
469 case 1200:
470 dcb.BaudRate = CBR_1200;
471 break;
472 case 2400:
473 dcb.BaudRate = CBR_2400;
474 break;
475 case 4800:
476 dcb.BaudRate = CBR_4800;
477 break;
478 case 9600:
479 dcb.BaudRate = CBR_9600;
480 break;
481 case 14400:
482 dcb.BaudRate = CBR_14400; /* Not available on Unix? */
483 break;
484 case 19200:
485 dcb.BaudRate = CBR_19200;
486 break;
487 case 38400:
488 dcb.BaudRate = CBR_38400;
489 break;
490 case 57600:
491 dcb.BaudRate = CBR_57600;
492 break;
493 case 115200:
494 dcb.BaudRate = CBR_115200;
495 break;
496 case 128000:
497 dcb.BaudRate = CBR_128000; /* Not available on Unix? */
498 break;
499 case 256000:
500 dcb.BaudRate = CBR_256000; /* Not available on Unix? */
501 break;
502 default:
503 return SP_ERR_ARG;
504 }
505
506 switch (stopbits) {
507 /* Note: There's also ONE5STOPBITS == 1.5 (unneeded so far). */
508 case 1:
509 dcb.StopBits = ONESTOPBIT;
510 break;
511 case 2:
512 dcb.StopBits = TWOSTOPBITS;
513 break;
514 default:
515 return SP_ERR_ARG;
516 }
517
518 switch (parity) {
519 /* Note: There's also SPACEPARITY, MARKPARITY (unneeded so far). */
520 case SP_PARITY_NONE:
521 dcb.Parity = NOPARITY;
522 break;
523 case SP_PARITY_EVEN:
524 dcb.Parity = EVENPARITY;
525 break;
526 case SP_PARITY_ODD:
527 dcb.Parity = ODDPARITY;
528 break;
529 default:
530 return SP_ERR_ARG;
531 }
532
533 if (rts != -1) {
534 if (rts)
535 dcb.fRtsControl = RTS_CONTROL_ENABLE;
536 else
537 dcb.fRtsControl = RTS_CONTROL_DISABLE;
538 }
539
540 if (dtr != -1) {
541 if (dtr)
542 dcb.fDtrControl = DTR_CONTROL_ENABLE;
543 else
544 dcb.fDtrControl = DTR_CONTROL_DISABLE;
545 }
546
547 if (!SetCommState(port->hdl, &dcb))
548 return SP_ERR_FAIL;
549#else
550 struct termios term;
551 speed_t baud;
552 int controlbits;
553
554 if (tcgetattr(port->fd, &term) < 0)
555 return SP_ERR_FAIL;
556
557 switch (baudrate) {
558 case 50:
559 baud = B50;
560 break;
561 case 75:
562 baud = B75;
563 break;
564 case 110:
565 baud = B110;
566 break;
567 case 134:
568 baud = B134;
569 break;
570 case 150:
571 baud = B150;
572 break;
573 case 200:
574 baud = B200;
575 break;
576 case 300:
577 baud = B300;
578 break;
579 case 600:
580 baud = B600;
581 break;
582 case 1200:
583 baud = B1200;
584 break;
585 case 1800:
586 baud = B1800;
587 break;
588 case 2400:
589 baud = B2400;
590 break;
591 case 4800:
592 baud = B4800;
593 break;
594 case 9600:
595 baud = B9600;
596 break;
597 case 19200:
598 baud = B19200;
599 break;
600 case 38400:
601 baud = B38400;
602 break;
603 case 57600:
604 baud = B57600;
605 break;
606 case 115200:
607 baud = B115200;
608 break;
609 case 230400:
610 baud = B230400;
611 break;
612#if !defined(__APPLE__) && !defined(__OpenBSD__)
613 case 460800:
614 baud = B460800;
615 break;
616#endif
617 default:
618 return SP_ERR_ARG;
619 }
620
621 if (cfsetospeed(&term, baud) < 0)
622 return SP_ERR_FAIL;
623
624 if (cfsetispeed(&term, baud) < 0)
625 return SP_ERR_FAIL;
626
627 term.c_cflag &= ~CSIZE;
628 switch (bits) {
629 case 8:
630 term.c_cflag |= CS8;
631 break;
632 case 7:
633 term.c_cflag |= CS7;
634 break;
635 default:
636 return SP_ERR_ARG;
637 }
638
639 term.c_cflag &= ~CSTOPB;
640 switch (stopbits) {
641 case 1:
642 term.c_cflag &= ~CSTOPB;
643 break;
644 case 2:
645 term.c_cflag |= CSTOPB;
646 break;
647 default:
648 return SP_ERR_ARG;
649 }
650
8683177b 651 term.c_iflag &= ~(IXON | IXOFF | IXANY);
74510d4b
ML		 652 term.c_cflag &= ~CRTSCTS;
653 switch (flowcontrol) {
654 case 0:
655 /* No flow control. */
656 break;
657 case 1:
658 term.c_cflag |= CRTSCTS;
659 break;
660 case 2:
8683177b 661 term.c_iflag |= IXON | IXOFF | IXANY;
74510d4b
ML		 662 break;
663 default:
664 return SP_ERR_ARG;
665 }
666
667 term.c_iflag &= ~IGNPAR;
8683177b 668 term.c_cflag &= ~(PARENB | PARODD);
74510d4b
ML		 669 switch (parity) {
670 case SP_PARITY_NONE:
671 term.c_iflag |= IGNPAR;
672 break;
673 case SP_PARITY_EVEN:
674 term.c_cflag |= PARENB;
675 break;
676 case SP_PARITY_ODD:
677 term.c_cflag |= PARENB | PARODD;
678 break;
679 default:
680 return SP_ERR_ARG;
681 }
682
683 /* Turn off all serial port cooking. */
684 term.c_iflag &= ~(ISTRIP | INLCR | ICRNL);
685 term.c_oflag &= ~(ONLCR | OCRNL | ONOCR);
686#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__)
687 term.c_oflag &= ~OFILL;
688#endif
689
690 /* Disable canonical mode, and don't echo input characters. */
691 term.c_lflag &= ~(ICANON | ECHO);
692
8683177b
ML		 693 /* Ignore modem status lines; enable receiver */
694 term.c_cflag |= (CLOCAL | CREAD);
695
74510d4b
ML		 696 /* Write the configured settings. */
697 if (tcsetattr(port->fd, TCSADRAIN, &term) < 0)
698 return SP_ERR_FAIL;
699
700 if (rts != -1) {
701 controlbits = TIOCM_RTS;
702 if (ioctl(port->fd, rts ? TIOCMBIS : TIOCMBIC,
703 &controlbits) < 0)
704 return SP_ERR_FAIL;
705 }
706
707 if (dtr != -1) {
708 controlbits = TIOCM_DTR;
709 if (ioctl(port->fd, dtr ? TIOCMBIS : TIOCMBIC,
710 &controlbits) < 0)
711 return SP_ERR_FAIL;
712 }
713#endif
714
715 return SP_OK;
716}
717
718/**
719 * Get error code for failed operation.
720 *
721 * In order to obtain the correct result, this function should be called
722 * straight after the failure, before executing any other system operations.
723 *
724 * @return The system's numeric code for the error that caused the last
725 * operation to fail.
726 */
727int sp_last_error_code(void)
728{
729#ifdef _WIN32
730 return GetLastError();
731#else
732 return errno;
733#endif
734}
735
736/**
737 * Get error message for failed operation.
738 *
739 * In order to obtain the correct result, this function should be called
740 * straight after the failure, before executing other system operations.
741 *
742 * @return The system's message for the error that caused the last
743 * operation to fail. This string may be allocated by the function,
744 * and can be freed after use by calling sp_free_error_message.
745 */
746char *sp_last_error_message(void)
747{
748#ifdef _WIN32
749 LPVOID message;
750 DWORD error = GetLastError();
751
752 FormatMessage(
753 FORMAT_MESSAGE_ALLOCATE_BUFFER |
754 FORMAT_MESSAGE_FROM_SYSTEM |
755 FORMAT_MESSAGE_IGNORE_INSERTS,
756 NULL,
757 error,
758 MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
759 (LPTSTR) &message,
760 0, NULL );
761
762 return message;
763#else
764 return strerror(errno);
765#endif
766}
767
768/**
769 * Free error message.
770 *
771 * This function can be used to free a string returned by the
772 * sp_last_error_message function.
773 */
774void sp_free_error_message(char *message)
775{
776#ifdef _WIN32
777 LocalFree(message);
64eec30d
ML		 778#else
779 (void)message;
74510d4b
ML		 780#endif
781}
Serial port access library