bool minmea_scan(const char *sentence, const char *format, ...)
{
bool result = false;
bool optional = false;
va_list ap;
va_start(ap, format);
const char *field = sentence;
#define next_field() \
do { \
/* Progress to the next field. */ \
while (minmea_isfield(*sentence)) \
sentence++; \
/* Make sure there is a field there. */ \
if (*sentence == ',') { \
sentence++; \
field = sentence; \
} else { \
field = NULL; \
} \
} while (0)
while (*format) {
char type = *format++;
if (type == ';') {
// All further fields are optional.
optional = true;
continue;
}
if (!field && !optional) {
// Field requested but we ran out if input. Bail out.
goto parse_error;
}
switch (type) {
case 'c': { // Single character field (char).
char value = '\0';
if (field && minmea_isfield(*field))
value = *field;
*va_arg(ap, char *) = value;
} break;
case 'd': { // Single character direction field (int).
int value = 0;
if (field && minmea_isfield(*field)) {
switch (*field) {
case 'N':
case 'E':
value = 1;
break;
case 'S':
case 'W':
value = -1;
break;
default:
goto parse_error;
}
}
*va_arg(ap, int *) = value;
} break;
case 'f': { // Fractional value with scale (struct minmea_float).
int sign = 0;
int_least32_t value = -1;
int_least32_t scale = 0;
if (field) {
while (minmea_isfield(*field)) {
if (*field == '+' && !sign && value == -1) {
sign = 1;
} else if (*field == '-' && !sign && value == -1) {
sign = -1;
} else if (isdigit((unsigned char) *field)) {
int digit = *field - '0';
if (value == -1)
value = 0;
if (value > (INT_LEAST32_MAX-digit) / 10) {
/* we ran out of bits, what do we do? */
if (scale) {
/* truncate extra precision */
break;
} else {
/* integer overflow. bail out. */
goto parse_error;
}
}
value = (10 * value) + digit;
if (scale)
scale *= 10;
} else if (*field == '.' && scale == 0) {
scale = 1;
} else if (*field == ' ') {
/* Allow spaces at the start of the field. Not NMEA
* conformant, but some modules do this. */
if (sign != 0 || value != -1 || scale != 0)
goto parse_error;
} else {
goto parse_error;
}
field++;
}
}
if ((sign || scale) && value == -1)
goto parse_error;
if (value == -1) {
/* No digits were scanned. */
value = 0;
scale = 0;
} else if (scale == 0) {
/* No decimal point. */
scale = 1;
}
if (sign)
value *= sign;
*va_arg(ap, struct minmea_float *) = (struct minmea_float) {value, scale};
} break;
case 'i': { // Integer value, default 0 (int).
int value = 0;
if (field) {
char *endptr;
value = strtol(field, &endptr, 10);
if (minmea_isfield(*endptr))
goto parse_error;
}
*va_arg(ap, int *) = value;
} break;
case 's': { // String value (char *).
char *buf = va_arg(ap, char *);
if (field) {
while (minmea_isfield(*field))
*buf++ = *field++;
}
*buf = '\0';
} break;
case 't': { // NMEA talker+sentence identifier (char *).
// This field is always mandatory.
if (!field)
goto parse_error;
if (field[0] != '$')
goto parse_error;
for (int f=0; f<5; f++)
if (!minmea_isfield(field[1+f]))
goto parse_error;
char *buf = va_arg(ap, char *);
memcpy(buf, field+1, 5);
buf[5] = '\0';
} break;
case 'D': { // Date (int, int, int), -1 if empty.
struct minmea_date *date = va_arg(ap, struct minmea_date *);
int d = -1, m = -1, y = -1;
if (field && minmea_isfield(*field)) {
// Always six digits.
for (int f=0; f<6; f++)
if (!isdigit((unsigned char) field[f]))
goto parse_error;
char dArr[] = {field[0], field[1], '\0'};
char mArr[] = {field[2], field[3], '\0'};
char yArr[] = {field[4], field[5], '\0'};
d = strtol(dArr, NULL, 10);
m = strtol(mArr, NULL, 10);
y = strtol(yArr, NULL, 10);
}
date->day = d;
date->month = m;
date->year = y;
} break;
case 'T': { // Time (int, int, int, int), -1 if empty.
struct minmea_time *time_ = va_arg(ap, struct minmea_time *);
int h = -1, i = -1, s = -1, u = -1;
if (field && minmea_isfield(*field)) {
// Minimum required: integer time.
for (int f=0; f<6; f++)
if (!isdigit((unsigned char) field[f]))
goto parse_error;
char hArr[] = {field[0], field[1], '\0'};
char iArr[] = {field[2], field[3], '\0'};
char sArr[] = {field[4], field[5], '\0'};
h = strtol(hArr, NULL, 10);
i = strtol(iArr, NULL, 10);
s = strtol(sArr, NULL, 10);
field += 6;
// Extra: fractional time. Saved as microseconds.
if (*field++ == '.') {
int value = 0;
int scale = 1000000;
while (isdigit((unsigned char) *field) && scale > 1) {
value = (value * 10) + (*field++ - '0');
scale /= 10;
}
u = value * scale;
} else {
u = 0;
}
}
time_->hours = h;
time_->minutes = i;
time_->seconds = s;
time_->microseconds = u;
} break;
case '_': { // Ignore the field.
} break;
default: { // Unknown.
goto parse_error;
} break;
}
next_field();
}
result = true;
parse_error:
va_end(ap);
return result;
}
bool minmea_scan(const char *sentence, const char *format, ...)
{
bool result = false;
bool optional = false;
va_list ap;
va_start(ap, format);
const char *field = sentence;
#define next_field() \
do { \
/* Progress to the next field. */ \
while (minmea_isfield(*sentence)) \
sentence++; \
/* Make sure there is a field there. */ \
if (*sentence == ',') { \
sentence++; \
field = sentence; \
} else { \
field = NULL; \
} \
} while (0)
while (*format) {
char type = *format++;
if (type == ';') {
// All further fields are optional.
optional = true;
continue;
}
if (!field && !optional) {
// Field requested but we ran out if input. Bail out.
goto parse_error;
}
switch (type) {
case 'c': { // Single character field (char).
char value = '\0';
if (field && minmea_isfield(*field))
value = *field;
*va_arg(ap, char *) = value;
} break;
case 'd': { // Single character direction field (int).
int value = 0;
if (field && minmea_isfield(*field)) {
switch (*field) {
case 'N':
case 'E':
value = 1;
break;
case 'S':
case 'W':
value = -1;
break;
default:
goto parse_error;
}
}
*va_arg(ap, int *) = value;
} break;
case 'f': { // Fractional value with scale (int, int).
int sign = 0;
int value = -1;
int scale = 0;
if (field) {
while (minmea_isfield(*field)) {
if (*field == '+' && !sign && value == -1) {
sign = 1;
} else if (*field == '-' && !sign && value == -1) {
sign = -1;
} else if (isdigit((unsigned char) *field)) {
if (value == -1)
value = 0;
value = (10 * value) + (*field - '0');
if (scale)
scale *= 10;
} else if (*field == '.' && scale == 0) {
scale = 1;
} else {
goto parse_error;
}
field++;
}
}
if ((sign || scale) && value == -1)
goto parse_error;
if (value == -1) {
value = 0;
scale = 0;
}
if (sign)
value *= sign;
*va_arg(ap, int *) = value;
*va_arg(ap, int *) = scale;
} break;
case 'i': { // Integer value, default 0 (int).
int value = 0;
if (field) {
char *endptr;
value = strtol(field, &endptr, 10);
if (minmea_isfield(*endptr))
goto parse_error;
}
*va_arg(ap, int *) = value;
} break;
case 's': { // String value (char *).
char *buf = va_arg(ap, char *);
if (field) {
while (minmea_isfield(*field))
*buf++ = *field++;
}
*buf = '\0';
} break;
case 't': { // NMEA talker+sentence identifier (char *).
// This field is always mandatory.
if (!field)
goto parse_error;
if (field[0] != '$')
goto parse_error;
for (int i=0; i<5; i++)
if (!minmea_isfield(field[1+i]))
goto parse_error;
char *buf = va_arg(ap, char *);
memcpy(buf, field+1, 5);
buf[5] = '\0';
} break;
case 'D': { // Date (int, int, int), -1 if empty.
struct minmea_date *date = va_arg(ap, struct minmea_date *);
int d = -1, m = -1, y = -1;
if (field && minmea_isfield(*field)) {
// Always six digits.
for (int i=0; i<6; i++)
if (!isdigit((unsigned char) field[i]))
goto parse_error;
d = strtol((char[]) {field[0], field[1], '\0'}, NULL, 10);
m = strtol((char[]) {field[2], field[3], '\0'}, NULL, 10);
y = strtol((char[]) {field[4], field[5], '\0'}, NULL, 10);
}
date->day = d;
date->month = m;
date->year = y;
} break;
bool minmea_scan(const char *sentence, const char *format, ...)
{
bool result = false;
va_list ap;
va_start(ap, format);
const char *field = sentence;
#define next_field() \
do { \
while (minmea_isfield(*sentence++)) {} \
field = sentence; \
} while (0)
while (*format) {
char type = *format++;
switch (type) {
case 'c': { // Single character field (char).
char value = '\0';
if (minmea_isfield(*field))
value = *field;
else
value = '\0';
*va_arg(ap, char *) = value;
} break;
case 'd': { // Single character direction field (int).
int value = 0;
if (minmea_isfield(*field)) {
switch (*field) {
case 'N':
case 'E':
value = 1;
break;
case 'S':
case 'W':
value = -1;
break;
default:
goto end;
}
}
*va_arg(ap, int *) = value;
} break;
case 'f': { // Fractional value with scale (int, int).
int sign = 0;
int value = -1;
int scale = 0;
while (minmea_isfield(*field)) {
if (*field == '+' && !sign && value == -1) {
sign = 1;
} else if (*field == '-' && !sign && value == -1) {
sign = -1;
} else if (isdigit((unsigned char) *field)) {
if (value == -1)
value = 0;
value = (10 * value) + (*field - '0');
if (scale)
scale *= 10;
} else if (*field == '.' && scale == 0) {
scale = 1;
} else {
goto end;
}
field++;
}
if ((sign || scale) && value == -1)
goto end;
if (value == -1) {
value = 0;
scale = 0;
}
if (sign)
value *= sign;
*va_arg(ap, int *) = value;
*va_arg(ap, int *) = scale;
} break;
case 'i': { // Integer value, default 0 (int).
int value;
char *endptr;
value = strtol(field, &endptr, 10);
if (minmea_isfield(*endptr))
goto end;
*va_arg(ap, int *) = value;
} break;
case 's': { // String value (char *).
char *buf = va_arg(ap, char *);
while (minmea_isfield(*field))
*buf++ = *field++;
*buf = '\0';
} break;
case 't': { // NMEA talker+sentence identifier (char *).
if (field[0] != '$')
goto end;
for (int i=0; i<5; i++)
if (!minmea_isfield(field[1+i]))
goto end;
char *buf = va_arg(ap, char *);
memcpy(buf, field+1, 5);
buf[5] = '\0';
} break;
case 'D': { // Date (int, int, int), -1 if empty.
struct minmea_date *date = va_arg(ap, struct minmea_date *);
int d = -1, m = -1, y = -1;
// Always six digits.
for (int i=0; i<6; i++)
if (!isdigit((unsigned char) field[i]))
goto end_D;
d = strtol((char[]) {field[0], field[1], '\0'}, NULL, 10);
m = strtol((char[]) {field[2], field[3], '\0'}, NULL, 10);
y = strtol((char[]) {field[4], field[5], '\0'}, NULL, 10);
end_D:
date->day = d;
date->month = m;
date->year = y;
} break;
bool minmea_scan(const char *sentence, const char *format, ...)
{
bool result = false;
bool optional = false;
va_list ap;
va_start(ap, format);
const char *field = sentence;
#define next_field() \
do { \
/* Progress to the next field. */ \
while (minmea_isfield(*sentence)) \
sentence++; \
/* Make sure there is a field there. */ \
if (*sentence == ',') { \
sentence++; \
field = sentence; \
} else { \
field = NULL; \
} \
} while (0)
while (*format) {
char type = *format++;
if (type == ';') {
// All further fields are optional.
optional = true;
continue;
}
if (!field && !optional) {
// Field requested but we ran out if input. Bail out.
goto parse_error;
}
switch (type) {
case 'c': { // Single character field (char).
char value = '\0';
if (field && minmea_isfield(*field))
value = *field;
*va_arg(ap, char *) = value;
} break;
case 'd': { // Single character direction field (int).
int value = 0;
if (field && minmea_isfield(*field)) {
switch (*field) {
case 'N':
case 'E':
value = 1;
break;
case 'S':
case 'W':
value = -1;
break;
default:
goto parse_error;
}
}
*va_arg(ap, int *) = value;
} break;
case 'f': { // Fractional value with scale (struct minmea_float).
int sign = 0;
int_least32_t value = -1;
int_least32_t scale = 0;
if (field) {
while (minmea_isfield(*field)) {
if (*field == '+' && !sign && value == -1) {
sign = 1;
} else if (*field == '-' && !sign && value == -1) {
sign = -1;
} else if (isdigit((unsigned char) *field)) {
int digit = *field - '0';
if (value == -1)
value = 0;
if (value > (INT_LEAST32_MAX-digit) / 10) {
/* we ran out of bits, what do we do? */
if (scale) {
/* truncate extra precision */
break;
} else {
/* integer overflow. bail out. */
goto parse_error;
}
}
value = (10 * value) + digit;
if (scale)
scale *= 10;
} else if (*field == '.' && scale == 0) {
scale = 1;
} else if (*field == ' ') {
/* Allow spaces at the start of the field. Not NMEA
* conformant, but some modules do this. */
if (sign != 0 || value != -1 || scale != 0)
goto parse_error;
} else {
goto parse_error;
}
field++;
}
}
if ((sign || scale) && value == -1)
goto parse_error;
if (value == -1) {
/* No digits were scanned. */
value = 0;
scale = 0;
} else if (scale == 0) {
/* No decimal point. */
scale = 1;
}
if (sign)
value *= sign;
*va_arg(ap, struct minmea_float *) = (struct minmea_float) {value, scale};
} break;
case 'i': { // Integer value, default 0 (int).
int value = 0;
if (field) {
char *endptr;
value = strtol(field, &endptr, 10);
if (minmea_isfield(*endptr))
goto parse_error;
}
*va_arg(ap, int *) = value;
} break;
case 's': { // String value (char *).
char *buf = va_arg(ap, char *);
if (field) {
while (minmea_isfield(*field))
*buf++ = *field++;
}
*buf = '\0';
} break;
case 't': { // NMEA talker+sentence identifier (char *).
// This field is always mandatory.
int f;
if (!field)
goto parse_error;
if (field[0] != '$')
goto parse_error;
for (f=0; f<5; f++)
if (!minmea_isfield(field[1+f]))
goto parse_error;
char *buf = va_arg(ap, char *);
memcpy(buf, field+1, 5);
buf[5] = '\0';
} break;
case 'D': { // Date (int, int, int), -1 if empty.
struct minmea_date *date = va_arg(ap, struct minmea_date *);
int d = -1, m = -1, y = -1;
if (field && minmea_isfield(*field)) {
int f;
// Always six digits.
for (f=0; f<6; f++)
if (!isdigit((unsigned char) field[f]))
goto parse_error;
d = strtol((char[]) {field[0], field[1], '\0'}, NULL, 10);
m = strtol((char[]) {field[2], field[3], '\0'}, NULL, 10);
y = strtol((char[]) {field[4], field[5], '\0'}, NULL, 10);
}
