稍微改造了一下
#include <stdio.h>
#include <string.h>
#include <io.h>
void findOutput(char *fileName, char *sign);
void main( void )
{
 // 这里文件路径和所要查找的标记可以指定用户输入
 // ...... 
 // ......
 findOutput("C:\\FileName.txt","TOOL:");
}
void findOutput(char *fileName, char *sign) {
 unsigned int fhand;
 unsigned int fileLen;
 unsigned int bytesRead;
 char *pDestStart;
 char *pDestEnd;
 char *buffer;
 char result[10000];
 
 // Open file (FileName.txt) 
 if((fhand = _open( fileName, 0x0000)) == -1)
  printf( "File not opened\n" );
 else {
  fileLen = _filelength( fhand ) + 1;
  buffer = new char[fileLen];
  
  if(( bytesRead = _read( fhand, buffer, fileLen )) <= 0)
   printf( "File access error!\n" );
  else {
   pDestStart = buffer;
   while(1) {
    pDestStart = strstr(pDestStart,sign);
    if (pDestStart == NULL)
     break;
    pDestStart += 6;
    pDestEnd = pDestStart;
    pDestEnd = strstr(pDestEnd,"\n");
    if (pDestEnd == NULL) {
     strncpy(result, pDestStart, fileLen - strlen(pDestStart));
     result[fileLen - strlen(pDestStart)] = 0;
     printf("%s\n",result);
     break;
    }
    strncpy(result, pDestStart, pDestEnd - pDestStart);
    result[pDestEnd - pDestStart] = 0;
    pDestEnd += 1;
    pDestStart = pDestEnd;
    printf("%s\n",result);
   }
  }
 }
 _close(fhand);
}