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Handle conversion of unicode names to char * on Windows.
[libserialport.git] / serialport.c
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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 102 DWORD type, index = 0;
8b532d9c
ML		 103 char *name;
104 int name_len;
3b63f34d
ML		 105
106 if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, _T("HARDWARE\\DEVICEMAP\\SERIALCOMM"),
107 0, KEY_QUERY_VALUE, &key) != ERROR_SUCCESS)
108 return NULL;
109 if (RegQueryInfoKey(key, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
bdfb5b8c 110 &max_value_len, &max_data_size, NULL, NULL) != ERROR_SUCCESS)
3b63f34d
ML		 111 goto out_close;
112 max_data_len = max_data_size / sizeof(TCHAR);
bdfb5b8c 113 if (!(value = malloc((max_value_len + 1) * sizeof(TCHAR))))
3b63f34d
ML		 114 goto out_close;
115 if (!(data = malloc((max_data_len + 1) * sizeof(TCHAR))))
bdfb5b8c 116 goto out_free_value;
3b63f34d 117 while (
bdfb5b8c 118 value_len = max_value_len,
3b63f34d 119 data_size = max_data_size,
bdfb5b8c 120 RegEnumValue(key, index, value, &value_len,
3b63f34d
ML		 121 NULL, &type, (LPBYTE)data, &data_size) == ERROR_SUCCESS)
122 {
123 data_len = data_size / sizeof(TCHAR);
124 data[data_len] = '\0';
8b532d9c
ML		 125#ifdef UNICODE
126 name_len = WideCharToMultiByte(CP_ACP, 0, data, -1, NULL, 0, NULL, NULL)
127#else
128 name_len = data_len + 1;
129#endif
130 if (!(name = malloc(name_len)))
131 goto out;
132#ifdef UNICODE
133 WideCharToMultiByte(CP_ACP, 0, data, -1, name, name_len, NULL, NULL);
134#else
135 strcpy(name, data);
136#endif
3b63f34d 137 if (type == REG_SZ)
8b532d9c 138 if (!(list = sp_list_append(list, name, name_len)))
3b63f34d
ML		 139 goto out;
140 index++;
141 }
142out:
143 free(data);
bdfb5b8c
ML		 144out_free_value:
145 free(value);
3b63f34d
ML		 146out_close:
147 RegCloseKey(key);
148 return list;
149#endif
150#ifdef __APPLE__
151 mach_port_t master;
152 CFMutableDictionaryRef classes;
153 io_iterator_t iter;
154 char *path;
155 io_object_t port;
156 CFTypeRef cf_path;
157 Boolean result;
158
159 if (IOMasterPort(MACH_PORT_NULL, &master) != KERN_SUCCESS)
160 return NULL;
161
162 if (!(classes = IOServiceMatching(kIOSerialBSDServiceValue)))
163 return NULL;
164
165 CFDictionarySetValue(classes,
166 CFSTR(kIOSerialBSDTypeKey), CFSTR(kIOSerialBSDAllTypes));
167
168 if (!(IOServiceGetMatchingServices(master, classes, &iter)))
169 return NULL;
170
171 if (!(path = malloc(PATH_MAX)))
172 goto out_release;
173
1ebf4347 174 while ((port = IOIteratorNext(iter))) {
3b63f34d
ML		 175 cf_path = IORegistryEntryCreateCFProperty(port,
176 CFSTR(kIOCalloutDeviceKey), kCFAllocatorDefault, 0);
177 if (cf_path) {
178 result = CFStringGetCString(cf_path,
179 path, PATH_MAX, kCFStringEncodingASCII);
180 CFRelease(cf_path);
181 if (result)
182 if (!(list = sp_list_append(list, path, strlen(path) + 1)))
183 {
184 IOObjectRelease(port);
185 goto out;
186 }
187 }
188 IOObjectRelease(port);
189 }
190
191out:
192 free(path);
193out_release:
194 IOObjectRelease(iter);
195 return list;
196#endif
197#ifdef __linux__
198 struct udev *ud;
199 struct udev_enumerate *ud_enumerate;
200 struct udev_list_entry *ud_list;
201 struct udev_list_entry *ud_entry;
202 const char *path;
08fe0bdb 203 struct udev_device *ud_dev, *ud_parent;
3b63f34d 204 const char *name;
4b97c9fc
ML		 205 const char *driver;
206 int fd, ioctl_result;
207 struct serial_struct serial_info;
3b63f34d
ML		 208
209 ud = udev_new();
210 ud_enumerate = udev_enumerate_new(ud);
211 udev_enumerate_add_match_subsystem(ud_enumerate, "tty");
212 udev_enumerate_scan_devices(ud_enumerate);
213 ud_list = udev_enumerate_get_list_entry(ud_enumerate);
3b63f34d
ML		 214 udev_list_entry_foreach(ud_entry, ud_list)
215 {
216 path = udev_list_entry_get_name(ud_entry);
217 ud_dev = udev_device_new_from_syspath(ud, path);
08fe0bdb
ML		 218 /* If there is no parent device, this is a virtual tty. */
219 ud_parent = udev_device_get_parent(ud_dev);
220 if (ud_parent == NULL)
221 {
222 udev_device_unref(ud_dev);
223 continue;
224 }
3b63f34d 225 name = udev_device_get_devnode(ud_dev);
4b97c9fc
ML		 226 /* The serial8250 driver has a hardcoded number of ports.
227 * The only way to tell which actually exist on a given system
228 * is to try to open them and make an ioctl call. */
229 driver = udev_device_get_driver(ud_parent);
230 if (driver && !strcmp(driver, "serial8250"))
231 {
232 if ((fd = open(name, O_RDWR | O_NONBLOCK | O_NOCTTY)) < 0)
233 goto skip;
234 ioctl_result = ioctl(fd, TIOCGSERIAL, &serial_info);
235 close(fd);
236 if (ioctl_result != 0)
237 goto skip;
238 if (serial_info.type == PORT_UNKNOWN)
239 goto skip;
240 }
3b63f34d 241 list = sp_list_append(list, (void *)name, strlen(name) + 1);
4b97c9fc 242skip:
3b63f34d
ML		 243 udev_device_unref(ud_dev);
244 if (!list)
245 goto out;
246 }
247out:
248 udev_enumerate_unref(ud_enumerate);
249 udev_unref(ud);
250 return list;
251#endif
252}
253
68ab64cc
ML		 254/**
255 * Free a port list returned by sp_list_ports.
256 */
d54e9004 257void sp_free_port_list(struct sp_port **list)
3b63f34d
ML		 258{
259 unsigned int i;
260 for (i = 0; list[i]; i++)
261 free(list[i]);
262 free(list);
263}
264
74510d4b
ML		 265static int sp_validate_port(struct sp_port *port)
266{
267 if (port == NULL)
268 return 0;
269#ifdef _WIN32
270 if (port->hdl == INVALID_HANDLE_VALUE)
271 return 0;
272#else
273 if (port->fd < 0)
274 return 0;
275#endif
276 return 1;
277}
278
279#define CHECK_PORT() do { if (!sp_validate_port(port)) return SP_ERR_ARG; } while (0)
280
281/**
282 * Open the specified serial port.
283 *
284 * @param port Pointer to empty port structure allocated by caller.
285 * @param portname Name of port to open.
286 * @param flags Flags to use when opening the serial port. Possible flags
287 * are: SP_MODE_RDWR, SP_MODE_RDONLY, SP_MODE_NONBLOCK.
288 *
289 * @return SP_OK on success, SP_ERR_FAIL on failure,
290 * or SP_ERR_ARG if an invalid port or name is passed.
291 */
d54e9004 292int sp_open(struct sp_port *port, int flags)
74510d4b
ML		 293{
294 if (!port)
295 return SP_ERR_ARG;
296
74510d4b
ML		 297#ifdef _WIN32
298 DWORD desired_access = 0, flags_and_attributes = 0;
299 /* Map 'flags' to the OS-specific settings. */
300 desired_access |= GENERIC_READ;
301 flags_and_attributes = FILE_ATTRIBUTE_NORMAL;
302 if (flags & SP_MODE_RDWR)
303 desired_access |= GENERIC_WRITE;
304 if (flags & SP_MODE_NONBLOCK)
305 flags_and_attributes |= FILE_FLAG_OVERLAPPED;
306
307 port->hdl = CreateFile(port->name, desired_access, 0, 0,
308 OPEN_EXISTING, flags_and_attributes, 0);
309 if (port->hdl == INVALID_HANDLE_VALUE)
310 return SP_ERR_FAIL;
311#else
312 int flags_local = 0;
313 /* Map 'flags' to the OS-specific settings. */
314 if (flags & SP_MODE_RDWR)
315 flags_local |= O_RDWR;
316 if (flags & SP_MODE_RDONLY)
317 flags_local |= O_RDONLY;
318 if (flags & SP_MODE_NONBLOCK)
319 flags_local |= O_NONBLOCK;
320
321 if ((port->fd = open(port->name, flags_local)) < 0)
322 return SP_ERR_FAIL;
323#endif
324
325 return SP_OK;
326}
327
328/**
329 * Close the specified serial port.
330 *
331 * @param port Pointer to port structure.
332 *
333 * @return SP_OK on success, SP_ERR_FAIL on failure,
334 * or SP_ERR_ARG if an invalid port is passed.
335 */
336int sp_close(struct sp_port *port)
337{
338 CHECK_PORT();
339
340#ifdef _WIN32
341 /* Returns non-zero upon success, 0 upon failure. */
342 if (CloseHandle(port->hdl) == 0)
343 return SP_ERR_FAIL;
344#else
345 /* Returns 0 upon success, -1 upon failure. */
346 if (close(port->fd) == -1)
347 return SP_ERR_FAIL;
348#endif
349
350 return SP_OK;
351}
352
353/**
354 * Flush serial port buffers.
355 *
356 * @param port Pointer to port structure.
357 *
358 * @return SP_OK on success, SP_ERR_FAIL on failure,
359 * or SP_ERR_ARG if an invalid port is passed.
360 */
361int sp_flush(struct sp_port *port)
362{
363 CHECK_PORT();
364
365#ifdef _WIN32
366 /* Returns non-zero upon success, 0 upon failure. */
367 if (PurgeComm(port->hdl, PURGE_RXCLEAR | PURGE_TXCLEAR) == 0)
368 return SP_ERR_FAIL;
369#else
370 /* Returns 0 upon success, -1 upon failure. */
371 if (tcflush(port->fd, TCIOFLUSH) < 0)
372 return SP_ERR_FAIL;
373#endif
374 return SP_OK;
375}
376
377/**
378 * Write a number of bytes to the specified serial port.
379 *
380 * @param port Pointer to port structure.
381 * @param buf Buffer containing the bytes to write.
382 * @param count Number of bytes to write.
383 *
384 * @return The number of bytes written, SP_ERR_FAIL on failure,
385 * or SP_ERR_ARG if an invalid port is passed.
386 */
387int sp_write(struct sp_port *port, const void *buf, size_t count)
388{
389 CHECK_PORT();
390
391 if (!buf)
392 return SP_ERR_ARG;
393
394#ifdef _WIN32
395 DWORD written = 0;
396 /* Returns non-zero upon success, 0 upon failure. */
397 if (WriteFile(port->hdl, buf, count, &written, NULL) == 0)
398 return SP_ERR_FAIL;
399 return written;
400#else
401 /* Returns the number of bytes written, or -1 upon failure. */
402 ssize_t written = write(port->fd, buf, count);
403 if (written < 0)
404 return SP_ERR_FAIL;
405 else
406 return written;;
407#endif
408}
409
410/**
411 * Read a number of bytes from the specified serial port.
412 *
413 * @param port Pointer to port structure.
414 * @param buf Buffer where to store the bytes that are read.
415 * @param count The number of bytes to read.
416 *
417 * @return The number of bytes read, SP_ERR_FAIL on failure,
418 * or SP_ERR_ARG if an invalid port is passed.
419 */
420int sp_read(struct sp_port *port, void *buf, size_t count)
421{
422 CHECK_PORT();
423
424 if (!buf)
425 return SP_ERR_ARG;
426
427#ifdef _WIN32
428 DWORD bytes_read = 0;
429 /* Returns non-zero upon success, 0 upon failure. */
430 if (ReadFile(port->hdl, buf, count, &bytes_read, NULL) == 0)
431 return SP_ERR_FAIL;
432 return bytes_read;
433#else
434 ssize_t bytes_read;
435 /* Returns the number of bytes read, or -1 upon failure. */
436 if ((bytes_read = read(port->fd, buf, count)) < 0)
437 return SP_ERR_FAIL;
438 return bytes_read;
439#endif
440}
441
442/**
443 * Set serial parameters for the specified serial port.
444 *
445 * @param port Pointer to port structure.
446 * @param baudrate The baudrate to set.
447 * @param bits The number of data bits to use.
448 * @param parity The parity setting to use (0 = none, 1 = even, 2 = odd).
449 * @param stopbits The number of stop bits to use (1 or 2).
450 * @param flowcontrol The flow control settings to use (0 = none, 1 = RTS/CTS,
451 * 2 = XON/XOFF).
452 *
453 * @return The number of bytes read, SP_ERR_FAIL on failure,
454 * or SP_ERR_ARG if an invalid argument is passed.
455 */
456int sp_set_params(struct sp_port *port, int baudrate,
457 int bits, int parity, int stopbits,
458 int flowcontrol, int rts, int dtr)
459{
460 CHECK_PORT();
461
462#ifdef _WIN32
463 DCB dcb;
464
465 if (!GetCommState(port->hdl, &dcb))
466 return SP_ERR_FAIL;
467
468 switch (baudrate) {
469 /*
470 * The baudrates 50/75/134/150/200/1800/230400/460800 do not seem to
471 * have documented CBR_* macros.
472 */
473 case 110:
474 dcb.BaudRate = CBR_110;
475 break;
476 case 300:
477 dcb.BaudRate = CBR_300;
478 break;
479 case 600:
480 dcb.BaudRate = CBR_600;
481 break;
482 case 1200:
483 dcb.BaudRate = CBR_1200;
484 break;
485 case 2400:
486 dcb.BaudRate = CBR_2400;
487 break;
488 case 4800:
489 dcb.BaudRate = CBR_4800;
490 break;
491 case 9600:
492 dcb.BaudRate = CBR_9600;
493 break;
494 case 14400:
495 dcb.BaudRate = CBR_14400; /* Not available on Unix? */
496 break;
497 case 19200:
498 dcb.BaudRate = CBR_19200;
499 break;
500 case 38400:
501 dcb.BaudRate = CBR_38400;
502 break;
503 case 57600:
504 dcb.BaudRate = CBR_57600;
505 break;
506 case 115200:
507 dcb.BaudRate = CBR_115200;
508 break;
509 case 128000:
510 dcb.BaudRate = CBR_128000; /* Not available on Unix? */
511 break;
512 case 256000:
513 dcb.BaudRate = CBR_256000; /* Not available on Unix? */
514 break;
515 default:
516 return SP_ERR_ARG;
517 }
518
519 switch (stopbits) {
520 /* Note: There's also ONE5STOPBITS == 1.5 (unneeded so far). */
521 case 1:
522 dcb.StopBits = ONESTOPBIT;
523 break;
524 case 2:
525 dcb.StopBits = TWOSTOPBITS;
526 break;
527 default:
528 return SP_ERR_ARG;
529 }
530
531 switch (parity) {
532 /* Note: There's also SPACEPARITY, MARKPARITY (unneeded so far). */
533 case SP_PARITY_NONE:
534 dcb.Parity = NOPARITY;
535 break;
536 case SP_PARITY_EVEN:
537 dcb.Parity = EVENPARITY;
538 break;
539 case SP_PARITY_ODD:
540 dcb.Parity = ODDPARITY;
541 break;
542 default:
543 return SP_ERR_ARG;
544 }
545
546 if (rts != -1) {
547 if (rts)
548 dcb.fRtsControl = RTS_CONTROL_ENABLE;
549 else
550 dcb.fRtsControl = RTS_CONTROL_DISABLE;
551 }
552
553 if (dtr != -1) {
554 if (dtr)
555 dcb.fDtrControl = DTR_CONTROL_ENABLE;
556 else
557 dcb.fDtrControl = DTR_CONTROL_DISABLE;
558 }
559
560 if (!SetCommState(port->hdl, &dcb))
561 return SP_ERR_FAIL;
562#else
563 struct termios term;
564 speed_t baud;
565 int controlbits;
566
567 if (tcgetattr(port->fd, &term) < 0)
568 return SP_ERR_FAIL;
569
570 switch (baudrate) {
571 case 50:
572 baud = B50;
573 break;
574 case 75:
575 baud = B75;
576 break;
577 case 110:
578 baud = B110;
579 break;
580 case 134:
581 baud = B134;
582 break;
583 case 150:
584 baud = B150;
585 break;
586 case 200:
587 baud = B200;
588 break;
589 case 300:
590 baud = B300;
591 break;
592 case 600:
593 baud = B600;
594 break;
595 case 1200:
596 baud = B1200;
597 break;
598 case 1800:
599 baud = B1800;
600 break;
601 case 2400:
602 baud = B2400;
603 break;
604 case 4800:
605 baud = B4800;
606 break;
607 case 9600:
608 baud = B9600;
609 break;
610 case 19200:
611 baud = B19200;
612 break;
613 case 38400:
614 baud = B38400;
615 break;
616 case 57600:
617 baud = B57600;
618 break;
619 case 115200:
620 baud = B115200;
621 break;
622 case 230400:
623 baud = B230400;
624 break;
625#if !defined(__APPLE__) && !defined(__OpenBSD__)
626 case 460800:
627 baud = B460800;
628 break;
629#endif
630 default:
631 return SP_ERR_ARG;
632 }
633
634 if (cfsetospeed(&term, baud) < 0)
635 return SP_ERR_FAIL;
636
637 if (cfsetispeed(&term, baud) < 0)
638 return SP_ERR_FAIL;
639
640 term.c_cflag &= ~CSIZE;
641 switch (bits) {
642 case 8:
643 term.c_cflag |= CS8;
644 break;
645 case 7:
646 term.c_cflag |= CS7;
647 break;
648 default:
649 return SP_ERR_ARG;
650 }
651
652 term.c_cflag &= ~CSTOPB;
653 switch (stopbits) {
654 case 1:
655 term.c_cflag &= ~CSTOPB;
656 break;
657 case 2:
658 term.c_cflag |= CSTOPB;
659 break;
660 default:
661 return SP_ERR_ARG;
662 }
663
8683177b 664 term.c_iflag &= ~(IXON | IXOFF | IXANY);
74510d4b
ML		 665 term.c_cflag &= ~CRTSCTS;
666 switch (flowcontrol) {
667 case 0:
668 /* No flow control. */
669 break;
670 case 1:
671 term.c_cflag |= CRTSCTS;
672 break;
673 case 2:
8683177b 674 term.c_iflag |= IXON | IXOFF | IXANY;
74510d4b
ML		 675 break;
676 default:
677 return SP_ERR_ARG;
678 }
679
680 term.c_iflag &= ~IGNPAR;
8683177b 681 term.c_cflag &= ~(PARENB | PARODD);
74510d4b
ML		 682 switch (parity) {
683 case SP_PARITY_NONE:
684 term.c_iflag |= IGNPAR;
685 break;
686 case SP_PARITY_EVEN:
687 term.c_cflag |= PARENB;
688 break;
689 case SP_PARITY_ODD:
690 term.c_cflag |= PARENB | PARODD;
691 break;
692 default:
693 return SP_ERR_ARG;
694 }
695
696 /* Turn off all serial port cooking. */
697 term.c_iflag &= ~(ISTRIP | INLCR | ICRNL);
698 term.c_oflag &= ~(ONLCR | OCRNL | ONOCR);
699#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__)
700 term.c_oflag &= ~OFILL;
701#endif
702
703 /* Disable canonical mode, and don't echo input characters. */
704 term.c_lflag &= ~(ICANON | ECHO);
705
8683177b
ML		 706 /* Ignore modem status lines; enable receiver */
707 term.c_cflag |= (CLOCAL | CREAD);
708
74510d4b
ML		 709 /* Write the configured settings. */
710 if (tcsetattr(port->fd, TCSADRAIN, &term) < 0)
711 return SP_ERR_FAIL;
712
713 if (rts != -1) {
714 controlbits = TIOCM_RTS;
715 if (ioctl(port->fd, rts ? TIOCMBIS : TIOCMBIC,
716 &controlbits) < 0)
717 return SP_ERR_FAIL;
718 }
719
720 if (dtr != -1) {
721 controlbits = TIOCM_DTR;
722 if (ioctl(port->fd, dtr ? TIOCMBIS : TIOCMBIC,
723 &controlbits) < 0)
724 return SP_ERR_FAIL;
725 }
726#endif
727
728 return SP_OK;
729}
730
731/**
732 * Get error code for failed operation.
733 *
734 * In order to obtain the correct result, this function should be called
735 * straight after the failure, before executing any other system operations.
736 *
737 * @return The system's numeric code for the error that caused the last
738 * operation to fail.
739 */
740int sp_last_error_code(void)
741{
742#ifdef _WIN32
743 return GetLastError();
744#else
745 return errno;
746#endif
747}
748
749/**
750 * Get error message for failed operation.
751 *
752 * In order to obtain the correct result, this function should be called
753 * straight after the failure, before executing other system operations.
754 *
755 * @return The system's message for the error that caused the last
756 * operation to fail. This string may be allocated by the function,
757 * and can be freed after use by calling sp_free_error_message.
758 */
759char *sp_last_error_message(void)
760{
761#ifdef _WIN32
762 LPVOID message;
763 DWORD error = GetLastError();
764
765 FormatMessage(
766 FORMAT_MESSAGE_ALLOCATE_BUFFER |
767 FORMAT_MESSAGE_FROM_SYSTEM |
768 FORMAT_MESSAGE_IGNORE_INSERTS,
769 NULL,
770 error,
771 MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
772 (LPTSTR) &message,
773 0, NULL );
774
775 return message;
776#else
777 return strerror(errno);
778#endif
779}
780
781/**
782 * Free error message.
783 *
784 * This function can be used to free a string returned by the
785 * sp_last_error_message function.
786 */
787void sp_free_error_message(char *message)
788{
789#ifdef _WIN32
790 LocalFree(message);
64eec30d
ML		 791#else
792 (void)message;
74510d4b
ML		 793#endif
794}
Serial port access library