str.cpp

来自「一个嵌入式系统的C代码」· C++ 代码 · 共 120 行

//***********************************************************************
//  MODULE : Str - Class Body						*
//  AUTHOR : Ron Chernich						*
//  PURPOSE: Derived from the Microsoft C/C++ tutorial material:	*
//	     \C700\SAMPLES\CPPTUTOR\STRNG.CPP				*
//  HISTORY:								*
//   12-JAN-93	First (MSC/C++ 7.00) version				*
//   19-MAY-93	Memory leakage through delete of array fixed		*
//***********************************************************************

#include "str.hpp"


//////////////
// Default constructor
//
Str::Str ()
{
  buf = NULL;
  length = 0;
}

//////////////
// Constructor that takes a const char *
//
Str::Str (const char *s)
{
  length = strlen(s);
  buf = new char[length + 1];
  strcpy(buf, s);
}

/////////////
// Constructor that takes a char and an int
//
Str::Str (char c, INT16 n)
{
  length = n;
  buf = new char[length + 1];
  memset(buf, c, length);
  buf[length] = '\0';
}

////////////
// Copy constructor
//
Str::Str (const Str &other)
{
  length = other.length;
  buf = new char[length + 1];
  strcpy(buf, other.buf);
}

////////////////
// Assign one string to another (watch out for both being same string!)
//
Str &Str::operator = (const Str &other)
{
  if (&other == this)
    return *this;
  DELETE_ARRAY buf;
  length = other.length;
  buf = new char[length + 1];
  strcpy(buf, other.buf);
  return *this;
}

///////////
// test for buffer contents equal to char array
// RETURNS: TRUE  .. same
//          FLASE .. different
//
BOOL Str::operator == (const char *psz)
{
  return (strncmp(buf, psz, length) == 0) ? TRUE : FALSE;
}

////////////
// Set a character in a String
//
void Str::StrSet (INT16 index, char newchar)
{
  if ((index > 0) && (index <= length))
    buf[index - 1] = newchar;
}

////////////
// Get a character in a String
//
char Str::StrGet (INT16 index) const
{
  return (((index > 0) && (index <= length)) ? buf[index - 1] : 0);
}

////////////////
// adds char(s) to tail of String
//
void Str::StrAppend (const char *addition)
{
  char *temp;

  length += strlen(addition);
  temp = new char[length + 1];	  // Allocate new buffer
  strcpy(temp, buf);		  // Copy contents of old buffer
  strcat(temp, addition);	  // Append new string
  DELETE_ARRAY buf;		  // Deallocate old buffer
  buf = temp;			  // reassign to new buffer
}

///////////////
// Destructor for a String
//
Str::~Str()
{
  DELETE_ARRAY buf;	 // Works even for empty String since delete 0 is safe
}


/********************************** EOF ***********************************/