سورس کد خواندن فایل تکست (سی پلاس پلاس)

کد:
Read Text Filesvoid main()

{

 char pcMyLines[10000]; ReadLines("C:\\MyTestFile.txt", 10, 5, pcMyLines, 12345);

}// This function reads n lines from a file

// Returns the amount of bytes read

int ReadLines(const char *pcFile, const int iStartLine, const int iTotLines, char *pcBuffer, const int iBufLen)

{

 FILE *fSrc;

 int   iLines = 0, j, iPos, iByteCount = 0; // Try to open the file

 if(fSrc = fopen(pcFile, "r"))

 {

   // Try to locate the starting line

   if(iPos = GetLinePos(fSrc, iStartLine))

   {

     // Set the starting position

     if(!fseek(fSrc, iPos, SEEK_SET))

     {

       // Read the lines

       for(iLines=0;iLines<iTotLines;iLines++)

       {

         // Read the line

         if((j = ReadLine(fSrc, iPos, pcBuffer, iBufLen - iByteCount)) == -1) break;

         iByteCount += j;

       }

     }

   }   // Close the file

   fclose(fSrc);

 } // Return the amount of bytes in the buffer, or -1 for failure

 return iLines == iTotLines ? iByteCount : -1;

}

// This function reads a single line from a file

int ReadLine(FILE *fSrc, const int iStartPos, char *pcBuffer, const int iBufLen)

{

 int iCount = 0; // Set the starting position

 if(!fseek(fSrc, iStartPos, SEEK_SET))

 {

   // Keep reading characters while we can

   while(!feof(fSrc) && (iCount < iBufLen))

   {

     // Read the character

     pcBuffer[iCount] = (char)fgetc(fSrc);

     if(pcBuffer[iCount++] == '\n') break;

   }

 }

 else iCount = -1; return iCount;

}// This function locates a line in a file

// Returns the position of the line in the file

int GetLinePos(FILE *fSrc, const int iLine, const int iStartPos /* 0 */)

{

 char  pcBuffer[4096];

 int   i, iPos = 0, iLines = 0, iBytes; // Set the start position

 if(!fseek(fSrc, iStartPos, SEEK_SET))

 {

   // Read the (next) block of data

   while(iBytes = fread(pcBuffer, sizeof(char), 4096, fSrc))

   {

     // Go through the block

     for(i=0;i<iBytes;i++)

     {

       // Do we have a new line?

       if(pcBuffer[i] == '\n')

       {

         // Update the line count

         iLines++;         // Have we reached the desired line?

         if(iLines == iLine)

         {

           // Store the position

           iPos += i;

           break;

         }

       }

     }     // Update the position

     iPos += iBytes;

   }

 } // Return the position of the line in the file, or -1 for failure

 return iLines == iLine ? iPos : -1;

}