prefs.cpp

一个嵌入式系统的C代码

//*************************************************************************
//  MODULE : System Initialization Parameters support module              *
//  AUTHOR : Ron Chernich                                                 *
//  PURPOSE: Class methods                                                *
//  HISTORY:                                                              *
//   21-MAR-95  First Version (MS Visual C++ 1.5)                         *
//*************************************************************************

#include "prefs.hpp"


///////////////////////////////////////////////////////////////////////////
// constructor tries to open the preferences file..
//
Preferences::Preferences (void)
{
  ini.open(PREFS_NAME, PREFS_MODE);
  BOOL  bOpen = __OPEN_TEST;
//  bOpen = FALSE;
  if (!bOpen)
    pBuffer = NULL;
  else {
    pBuffer = new char[MAX_PREF];
    if (NULL == pBuffer) {
      ini.close();
      bOpen = FALSE;
    }
  }
}

/////////
// close prefs file, if open
//
Preferences::~Preferences (void)
{
  if (bOpen) {
    ini.close();
    DELETE_ARRAY pBuffer;
  }
}

/////////////////
// The INI file contains lines of the form:
//
//     KEY = VALUE ;COMMENT
//
// (the whitespace around the VALUE and the comment are optional
// This private member scans the file for a line starting
// with the passed key string (ignoring case) and extracts the Value stuff
// If a comment is present, it and any trailing white space are deleted.
// RETURNS: pointer to the first non-space char after the equals sign or NULL
//
char *Preferences::FindKey (const char *pszKey)
{
  ini.seekg(0);
  for (;;)
  {
    if (ini.eof())
      break;
    ini.getline(pBuffer, MAX_PREF);
    char *cp = pBuffer;
    while (*cp)
      tolower(*cp++);

  #ifdef _DOS_ENV
    if (0 == strnicmp(pBuffer, pszKey, strlen(pszKey))) {
  #endif

  #ifdef UNIX  // why do they use casecmp instead of icmp (which is standard?)
    if ( strncasecmp(pBuffer, pszKey, strlen(pszKey))) {
  #endif

      cp = strchr(pBuffer, '=');
      if (*cp)
      {
	while (*cp)
	  if (SPACE != *(++cp))
	    break;
	if (*cp)
	{
	  char *cp2 = strchr(cp, ';');
	  if (cp2)
	  {
	    while (SPACE == *(cp2 - 1))
	      --cp2;
	    *cp2 = '\0';
	  }
	}
      }
      return cp;
    }
  }
  return 0;
}

///////////////
// find and return the integer value associated with the passed key tag
// string.  If not found (or no INI file) return the passed default value
// RETURNS: Integer value for key identifier
//
UINT16 Preferences::GetPrefInt (const char *pszKey, UINT16 nDef)
{
  UINT16 nVal = nDef;
  if (bOpen) {
    char *cp = FindKey(pszKey);
    if (cp)
      nDef = (UINT16)atoi(cp);
  }
  return nDef;
}

////////////
// find the passed key tag in the INI file and copy to the callers buffer
// If not found (or no INI file) use the passed default value
// RETURNS: Number of characters copied
//
UINT16 Preferences::GetPrefStr
  (const char *pszKey, const char *pszDef, char *psz, UINT16 n)
{
  if (!bOpen)
    strncpy(psz, pszDef, n);
  else {
    char *cp = FindKey(pszKey);
    if (cp)
      strncpy(psz, cp, n);
    else
      strncpy(psz, pszDef, n);
  }
  return strlen(psz);
}

///////////////////////////////// EOF //////////////////////////////////////