Parser for AT commands and similar protocols
Diff: ATParser.cpp
- Revision:
- 12:7d3c3f7ce928
- Parent:
- 11:fd406d4c4227
- Child:
- 13:46a18ad08efc
diff -r fd406d4c4227 -r 7d3c3f7ce928 ATParser.cpp --- a/ATParser.cpp Mon Dec 28 05:37:44 2015 +0000 +++ b/ATParser.cpp Thu Feb 18 15:59:15 2016 -0600 @@ -1,310 +1,310 @@ -/* Copyright (c) 2015 ARM Limited - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - * - * @section DESCRIPTION - * - * Parser for the AT command syntax - * - */ - -#include "ATParser.h" -#include "mbed_debug.h" - - -// getc/putc handling with timeouts -int ATParser::putc(char c) -{ - Timer timer; - timer.start(); - - while (true) { - if (_serial->writeable()) { - return _serial->putc(c); - } - if (timer.read_ms() > _timeout) { - return -1; - } - } -} - -int ATParser::getc() -{ - Timer timer; - timer.start(); - - while (true) { - if (_serial->readable()) { - return _serial->getc(); - } - if (timer.read_ms() > _timeout) { - return -1; - } - } -} - -void ATParser::flush() -{ - while (_serial->readable()) { - _serial->getc(); - } -} - - -// read/write handling with timeouts -int ATParser::write(const char *data, int size) -{ - int i = 0; - for ( ; i < size; i++) { - if (putc(data[i]) < 0) { - return -1; - } - } - return i; -} - -int ATParser::read(char *data, int size) -{ - int i = 0; - for ( ; i < size; i++) { - int c = getc(); - if (c < 0) { - return -1; - } - data[i] = c; - } - return i; -} - - -// printf/scanf handling -int ATParser::vprintf(const char *format, va_list args) -{ - if (vsprintf(_buffer, format, args) < 0) { - return false; - } - int i = 0; - for ( ; _buffer[i]; i++) { - if (putc(_buffer[i]) < 0) { - return -1; - } - } - return i; -} - -int ATParser::vscanf(const char *format, va_list args) -{ - // Since format is const, we need to copy it into our buffer to - // add the line's null terminator and clobber value-matches with asterisks. - // - // We just use the beginning of the buffer to avoid unnecessary allocations. - int i = 0; - int offset = 0; - - while (format[i]) { - if (format[i] == '%' && format[i+1] != '%' && format[i+1] != '*') { - _buffer[offset++] = '%'; - _buffer[offset++] = '*'; - i++; - } else { - _buffer[offset++] = format[i++]; - } - } - - // Scanf has very poor support for catching errors - // fortunately, we can abuse the %n specifier to determine - // if the entire string was matched. - _buffer[offset++] = '%'; - _buffer[offset++] = 'n'; - _buffer[offset++] = 0; - - // To workaround scanf's lack of error reporting, we actually - // make two passes. One checks the validity with the modified - // format string that only stores the matched characters (%n). - // The other reads in the actual matched values. - // - // We keep trying the match until we succeed or some other error - // derails us. - int j = 0; - - while (true) { - // Ran out of space - if (j+1 >= _buffer_size - offset) { - return false; - } - // Recieve next character - int c = getc(); - if (c < 0) { - return -1; - } - _buffer[offset + j++] = c; - _buffer[offset + j] = 0; - - // Check for match - int count = -1; - sscanf(_buffer+offset, _buffer, &count); - - // We only succeed if all characters in the response are matched - if (count == j) { - // Store the found results - vsscanf(_buffer+offset, format, args); - return j; - } - } -} - - -// Command parsing with line handling -bool ATParser::vsend(const char *command, va_list args) -{ - // Create and send command - if (vsprintf(_buffer, command, args) < 0) { - return false; - } - for (int i = 0; _buffer[i]; i++) { - if (putc(_buffer[i]) < 0) { - return false; - } - } - - // Finish with newline - for (int i = 0; _delimiter[i]; i++) { - if (putc(_delimiter[i]) < 0) { - return false; - } - } - - debug_if(dbg_on, "AT> %s\r\n", _buffer); - return true; -} - -bool ATParser::vrecv(const char *response, va_list args) -{ - // Iterate through each line in the expected response - while (response[0]) { - // Since response is const, we need to copy it into our buffer to - // add the line's null terminator and clobber value-matches with asterisks. - // - // We just use the beginning of the buffer to avoid unnecessary allocations. - int i = 0; - int offset = 0; - - while (response[i]) { - if (memcmp(&response[i+1-_delim_size], _delimiter, _delim_size) == 0) { - i++; - break; - } else if (response[i] == '%' && response[i+1] != '%' && response[i+1] != '*') { - _buffer[offset++] = '%'; - _buffer[offset++] = '*'; - i++; - } else { - _buffer[offset++] = response[i++]; - } - } - - // Scanf has very poor support for catching errors - // fortunately, we can abuse the %n specifier to determine - // if the entire string was matched. - _buffer[offset++] = '%'; - _buffer[offset++] = 'n'; - _buffer[offset++] = 0; - - // To workaround scanf's lack of error reporting, we actually - // make two passes. One checks the validity with the modified - // format string that only stores the matched characters (%n). - // The other reads in the actual matched values. - // - // We keep trying the match until we succeed or some other error - // derails us. - int j = 0; - - while (true) { - // Ran out of space - if (j+1 >= _buffer_size - offset) { - return false; - } - // Recieve next character - int c = getc(); - if (c < 0) { - return false; - } - _buffer[offset + j++] = c; - _buffer[offset + j] = 0; - - // Check for match - int count = -1; - sscanf(_buffer+offset, _buffer, &count); - - // We only succeed if all characters in the response are matched - if (count == j) { - debug_if(dbg_on, "AT= %s\r\n", _buffer+offset); - // Reuse the front end of the buffer - memcpy(_buffer, response, i); - _buffer[i] = 0; - - // Store the found results - vsscanf(_buffer+offset, _buffer, args); - - // Jump to next line and continue parsing - response += i; - break; - } - - // Clear the buffer when we hit a newline - if (strcmp(&_buffer[offset + j-_delim_size], _delimiter) == 0) { - debug_if(dbg_on, "AT< %s", _buffer+offset); - j = 0; - } - } - } - - return true; -} - - -// Mapping to vararg functions -int ATParser::printf(const char *format, ...) -{ - va_list args; - va_start(args, format); - int res = vprintf(format, args); - va_end(args); - return res; -} - -int ATParser::scanf(const char *format, ...) -{ - va_list args; - va_start(args, format); - int res = vscanf(format, args); - va_end(args); - return res; -} - -bool ATParser::send(const char *command, ...) -{ - va_list args; - va_start(args, command); - bool res = vsend(command, args); - va_end(args); - return res; -} - -bool ATParser::recv(const char *response, ...) -{ - va_list args; - va_start(args, response); - bool res = vrecv(response, args); - va_end(args); - return res; -} +/* Copyright (c) 2015 ARM Limited + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * @section DESCRIPTION + * + * Parser for the AT command syntax + * + */ + +#include "ATParser.h" +#include "mbed_debug.h" + + +// getc/putc handling with timeouts +int ATParser::putc(char c) +{ + Timer timer; + timer.start(); + + while (true) { + if (_serial->writeable()) { + return _serial->putc(c); + } + if (timer.read_ms() > _timeout) { + return -1; + } + } +} + +int ATParser::getc() +{ + Timer timer; + timer.start(); + + while (true) { + if (_serial->readable()) { + return _serial->getc(); + } + if (timer.read_ms() > _timeout) { + return -1; + } + } +} + +void ATParser::flush() +{ + while (_serial->readable()) { + _serial->getc(); + } +} + + +// read/write handling with timeouts +int ATParser::write(const char *data, int size) +{ + int i = 0; + for ( ; i < size; i++) { + if (putc(data[i]) < 0) { + return -1; + } + } + return i; +} + +int ATParser::read(char *data, int size) +{ + int i = 0; + for ( ; i < size; i++) { + int c = getc(); + if (c < 0) { + return -1; + } + data[i] = c; + } + return i; +} + + +// printf/scanf handling +int ATParser::vprintf(const char *format, va_list args) +{ + if (vsprintf(_buffer, format, args) < 0) { + return false; + } + int i = 0; + for ( ; _buffer[i]; i++) { + if (putc(_buffer[i]) < 0) { + return -1; + } + } + return i; +} + +int ATParser::vscanf(const char *format, va_list args) +{ + // Since format is const, we need to copy it into our buffer to + // add the line's null terminator and clobber value-matches with asterisks. + // + // We just use the beginning of the buffer to avoid unnecessary allocations. + int i = 0; + int offset = 0; + + while (format[i]) { + if (format[i] == '%' && format[i+1] != '%' && format[i+1] != '*') { + _buffer[offset++] = '%'; + _buffer[offset++] = '*'; + i++; + } else { + _buffer[offset++] = format[i++]; + } + } + + // Scanf has very poor support for catching errors + // fortunately, we can abuse the %n specifier to determine + // if the entire string was matched. + _buffer[offset++] = '%'; + _buffer[offset++] = 'n'; + _buffer[offset++] = 0; + + // To workaround scanf's lack of error reporting, we actually + // make two passes. One checks the validity with the modified + // format string that only stores the matched characters (%n). + // The other reads in the actual matched values. + // + // We keep trying the match until we succeed or some other error + // derails us. + int j = 0; + + while (true) { + // Ran out of space + if (j+1 >= _buffer_size - offset) { + return false; + } + // Recieve next character + int c = getc(); + if (c < 0) { + return -1; + } + _buffer[offset + j++] = c; + _buffer[offset + j] = 0; + + // Check for match + int count = -1; + sscanf(_buffer+offset, _buffer, &count); + + // We only succeed if all characters in the response are matched + if (count == j) { + // Store the found results + vsscanf(_buffer+offset, format, args); + return j; + } + } +} + + +// Command parsing with line handling +bool ATParser::vsend(const char *command, va_list args) +{ + // Create and send command + if (vsprintf(_buffer, command, args) < 0) { + return false; + } + for (int i = 0; _buffer[i]; i++) { + if (putc(_buffer[i]) < 0) { + return false; + } + } + + // Finish with newline + for (int i = 0; _delimiter[i]; i++) { + if (putc(_delimiter[i]) < 0) { + return false; + } + } + + debug_if(dbg_on, "AT> %s\r\n", _buffer); + return true; +} + +bool ATParser::vrecv(const char *response, va_list args) +{ + // Iterate through each line in the expected response + while (response[0]) { + // Since response is const, we need to copy it into our buffer to + // add the line's null terminator and clobber value-matches with asterisks. + // + // We just use the beginning of the buffer to avoid unnecessary allocations. + int i = 0; + int offset = 0; + + while (response[i]) { + if (memcmp(&response[i+1-_delim_size], _delimiter, _delim_size) == 0) { + i++; + break; + } else if (response[i] == '%' && response[i+1] != '%' && response[i+1] != '*') { + _buffer[offset++] = '%'; + _buffer[offset++] = '*'; + i++; + } else { + _buffer[offset++] = response[i++]; + } + } + + // Scanf has very poor support for catching errors + // fortunately, we can abuse the %n specifier to determine + // if the entire string was matched. + _buffer[offset++] = '%'; + _buffer[offset++] = 'n'; + _buffer[offset++] = 0; + + // To workaround scanf's lack of error reporting, we actually + // make two passes. One checks the validity with the modified + // format string that only stores the matched characters (%n). + // The other reads in the actual matched values. + // + // We keep trying the match until we succeed or some other error + // derails us. + int j = 0; + + while (true) { + // Ran out of space + if (j+1 >= _buffer_size - offset) { + return false; + } + // Recieve next character + int c = getc(); + if (c < 0) { + return false; + } + _buffer[offset + j++] = c; + _buffer[offset + j] = 0; + + // Check for match + int count = -1; + sscanf(_buffer+offset, _buffer, &count); + + // We only succeed if all characters in the response are matched + if (count == j) { + debug_if(dbg_on, "AT= %s\r\n", _buffer+offset); + // Reuse the front end of the buffer + memcpy(_buffer, response, i); + _buffer[i] = 0; + + // Store the found results + vsscanf(_buffer+offset, _buffer, args); + + // Jump to next line and continue parsing + response += i; + break; + } + + // Clear the buffer when we hit a newline + if (strcmp(&_buffer[offset + j-_delim_size], _delimiter) == 0) { + debug_if(dbg_on, "AT< %s", _buffer+offset); + j = 0; + } + } + } + + return true; +} + + +// Mapping to vararg functions +int ATParser::printf(const char *format, ...) +{ + va_list args; + va_start(args, format); + int res = vprintf(format, args); + va_end(args); + return res; +} + +int ATParser::scanf(const char *format, ...) +{ + va_list args; + va_start(args, format); + int res = vscanf(format, args); + va_end(args); + return res; +} + +bool ATParser::send(const char *command, ...) +{ + va_list args; + va_start(args, command); + bool res = vsend(command, args); + va_end(args); + return res; +} + +bool ATParser::recv(const char *response, ...) +{ + va_list args; + va_start(args, response); + bool res = vrecv(response, args); + va_end(args); + return res; +}