conversions.cpp

00001 /**
00002  * @defgroup conversions Data Structure Conversions
00003  * @{
00004  */
00005 
00006 #include <sstream>
00007 #include <iomanip>
00008 #include <vector>
00009 #include "conversions.h"
00010 
00011 /**
00012  *  @brief  Converts a C++ string to C-string; Use free() to release mem after copying the content.
00013  *  @author Lau Lee Hong
00014  *  @param  str C++ string
00015  *  @return Pointer to a null-terminated array of character
00016  */
00017 char* StringToChar(const std::string& str) 
00018 {
00019     char* buffer = (char*)std::malloc(std::strlen(str.c_str()) + 1);
00020     if(buffer != NULL)
00021     {
00022         std::strcpy(buffer, str.c_str());
00023     }
00024     
00025     return buffer; 
00026 }
00027 
00028 /**
00029  *  @brief  Converts an int-type to string-type hex.
00030  *  @author Lau Lee Hong
00031  *  @param  i Integer to be converted to hex string
00032  *  @return Hexadecimal of string format
00033  */
00034 std::string IntToHex(uint32_t i)
00035 {
00036   std::stringstream stream;
00037   stream << std::hex << i;
00038   return stream.str();
00039 }
00040 
00041 /**
00042  *  @brief  Converts an int-type to string.
00043  *  @author Lau Lee Hong
00044  *  @param  i (int)integer to be converted (std::string)integer
00045  *  @return Integer of string format
00046  */
00047 std::string IntToString(int v)
00048 {
00049     std::ostringstream oss;
00050     oss << v;
00051     return oss.str();
00052 }
00053 
00054 /**
00055  *  @brief  Converts an double-type to a C-string with variable number of decimal places.
00056  *  @author Lau Lee Hong
00057  *  @param  str             buffer to store result
00058  *  @param  v               value
00059  *  @param  decimal_digits  number of decimal places
00060  *  @return Null-terminated charcter array of double value with user-defined number of decimal places
00061  */
00062 char* DoubleToChar(char* str, double v, int decimal_digits)
00063 {
00064     int i = 1;
00065     int int_part, fract_part;
00066     int len;
00067     char *ptr;
00068 
00069     /* Prepare decimal digits multiplicator */
00070     for (; decimal_digits != 0; i *= 10, decimal_digits--);
00071 
00072     /* Calculate integer & fractional parts */
00073     int_part = (int)v;
00074     fract_part = (int)((v - (double)(int)v) * i);
00075 
00076     /* Fill in integer part */
00077     std::sprintf(str, "%i.", int_part);
00078 
00079     /* Prepare fill in of fractional part */
00080     len = std::strlen(str);
00081     ptr = &str[len];
00082 
00083     /* Fill in leading fractional zeros */
00084     for (i /= 10; i > 1; i /= 10, ptr++)
00085     {
00086         if (fract_part >= i)
00087         {
00088             break;
00089         }
00090         *ptr = '0';
00091     }
00092 
00093     /* Fill in (rest of) fractional part */
00094     std::sprintf(ptr, "%i", fract_part);
00095 
00096     return str;
00097 }
00098 
00099 /**
00100  *  @brief  Converts a C++ string to an integer
00101  *  @author Lee Tze Han
00102  *  @param  str C++ string
00103  *  @return Integer from string representation
00104  */
00105 int StringToInt(const std::string& str)
00106 {
00107     std::istringstream iss(str);
00108     int v;
00109     iss >> v;
00110     return v;   
00111 }
00112 
00113 /**
00114  *  @brief  Converts a time_t object (from NTPClient) to a C++ string
00115  *  @author Lee Tze Han
00116  *  @param  time time_t representing current time
00117  *  @return String representation of the underlying typedef'd uint32_t
00118  */
00119 //std::string TimeToString(const std::time_t time)
00120 //{
00121 //    std::ostringstream oss;
00122 //    oss << time;
00123 //    return oss.str();   
00124 //}
00125 //
00126 ///**
00127 // *  @brief  Converts a C++ string to time_t object
00128 // *  @author Lee Tze Han
00129 // *  @param  str C++ string
00130 // *  @return time_t from string representation
00131 // */
00132 //std::time_t StringToTime(const std::string& str)
00133 //{
00134 //    std::istringstream iss(str);
00135 //    std::time_t time;
00136 //    iss >> time;
00137 //    return time;    
00138 //}
00139 
00140 /** @}*/