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snprintf 溢出并随机打印垃圾到文件。帮助

发布于 2024-09-28 13:06:16 字数 14618 浏览 3 评论 0原文

这是我的代码，基本上是我测试过的 4 台计算机中的一台，它们都可以完美地处理非常大的数据大小，例如大小高达 500mb 的文本文件，但是当我在具有真实数据的服务器上运行它们时，甚至文件小至 6mb似乎在某个地方溢出并将垃圾写入我的文件末尾。

这是整个函数的源代码，以便人们可以更深入地了解

/** Reads values from tagname between start_time and end_time which are strings in the format 
 of 01/01/1970-12:00, a null string is treated as 01/01/1970, values are stored in
 "tagname".csv */
int ReadValues(char * tagname, char * start_time, char * end_time, char * working_directory, char * new_tag_name)
{
 long lRet;
 int  number_of_samples;
 int     loop;
 IHU_DATA_SAMPLE  * pSamples=NULL;
 IHU_TIMESTAMP  StartTime;
 IHU_TIMESTAMP  EndTime;
 FILE *stream;
 char outputFileName[200];
 char szQuality[100];
 char    newTempTagName[100];
 int  Year;
 int  Month;
 int  Day;
 int  Hour;
 int  Minute;
 int  Second;
 long Subsecond;
 int date[10];

    //if we want to change the tagname do it now
 if(new_tag_name != 0){
       strncpy(newTempTagName, new_tag_name, 100);
    } else {
       strncpy(newTempTagName, tagname, 100);  
    } 

 // if the tagname contains a character that is invalid for a filename then we have to make a name
 if ( (strstr(newTempTagName, "/")) || (strstr(newTempTagName, "\\")) || (strstr(newTempTagName, ":")))
 {

  sprintf(outputFileName, "MadeUpTag%d", MadeUpTagCount++);
 }
 else
 {

        //If a working directory was passed in use it
        if(!working_directory){           
            strncpy(outputFileName, newTempTagName,199);   
            } else {
      strcpy(outputFileName, working_directory); //Copy the working directory to the filename
      // Append a / on the end of the working directory if it doesn't already have one
         if(outputFileName[strlen(outputFileName)-1] == '\"'){                   
                outputFileName[strlen(outputFileName)-1] = 0;
            } 
            if(outputFileName[strlen(outputFileName)-1] != '\\'){         
                strncat(outputFileName, "\\", 199);                                
            }
            strncat(outputFileName, newTempTagName, 199);   //Copy the tagname to the end of the working directory
        }

 }

 //Add the csv file extension
 strcat(outputFileName, ".csv");
 #ifdef DEBUG
 printf("Output filename: %s\n", outputFileName);
 #endif

 stream = fopen(outputFileName, "w");
 if( stream == NULL ) {
  printf("The file %s can not be opened\n", outputFileName );
 } else {

  //If start_time == 0 we want to start at 1970
  if(start_time == 0){
   // we want all the data so use an old start time
   struct tm local;
   local.tm_year = date[2] - 1900;
   local.tm_mon = date[1] - 1;
   local.tm_mday = date[0];
   local.tm_hour = date[3];
   local.tm_min = date[4];
   local.tm_sec = 0;
            time_t utc_seconds = mktime(&local);
   StartTime.Seconds = (long)utc_seconds;
            StartTime.Subseconds = 0; 

  } else {
            //we have been supplied a start time
   #ifdef DEBUG
            printf("Start Time: ");
   #endif
            lRet = convert_date(start_time, &StartTime);
   #ifdef DEBUG

   printf("Seconds %ld \n", StartTime.Seconds);
   #endif
  }

  //if end_time == 0 we want to go all the way until now.
  if(end_time == 0){
   // end time of 0 means now
   memset(&EndTime, 0, sizeof(EndTime));
  } else {
            //we have been supplied an end time
   #ifdef DEBUG
            printf("End Time: ");
   #endif
            lRet = convert_date(end_time, &EndTime);
   #ifdef DEBUG
            printf("Seconds %ld \n", EndTime.Seconds);
   #endif
  }

  // API will determine actual samples that are in that time range
  number_of_samples=0;

  // API will allocate the memory
  pSamples = NULL;
     //timeTaken();
  lRet = ihuReadRawDataByTime
  (
   serverhandle,  // the handle returned from the connect
   tagname,   // the single tagname to retrieve 
   &StartTime,   // start time for query
   &EndTime,   // end time for query
   &number_of_samples, // will be set by API
   &pSamples   // will be allocated and populated in the user API
  );

        char temp[100];
        char Header[100];
        char lengthOfHeader = 0;
        char SampleAndTag[100];
        int  lengthOfSampleAndTag = 0;
        char ActualSample[100];
        int  lengthOfActualSample = 0;
        char NumberOfSamples[100];
        int  lengthOfNumberOfSamples = 0;
  int  oldQualityStatus = 99999;

  if (lRet == ihuSTATUS_OK)
  { 

      // successful read
            lengthOfHeader = snprintf(Header, 100, "[Data]\nTagname,TimeStamp,Value,DataQuality\n");
            if(lengthOfHeader < 0){
                printf("ERROR WRITING TO BUFFER!\n");                                 
            } else {
                if(fwrite(Header, 1, lengthOfHeader, stream) < lengthOfHeader){
                        printf("ERROR WRITING TO FILE!\n");
                }
            }

   for (loop = 0;loop < number_of_samples;loop++)
   {
                struct tm * local;
                local = localtime(&pSamples[loop].TimeStamp.Seconds);
                Month = local->tm_mon + 1;
                Day = local->tm_mday;
                Year = local->tm_year + 1900;
                Hour = local->tm_hour;
                Minute = local->tm_min;
                Second = local->tm_sec;
                Subsecond = pSamples[loop].TimeStamp.Subseconds;

                //lengthOfSampleAndTag = snprintf(SampleAndTag, 100, "Sample %d, %s",loop, newTempTagName);
                lengthOfSampleAndTag = snprintf(SampleAndTag, 100, "%s", newTempTagName);
                if(lengthOfSampleAndTag < 0){
                   printf("ERROR WRITING TO BUFFER!\n");                                 
                } else {
                    if(fwrite(SampleAndTag, 1,lengthOfSampleAndTag, stream) < lengthOfSampleAndTag){
                        printf("ERROR WRITING TO FILE!\n");
                    }
                }

                //Doing the formatting ourselves manually per character saves about 20% of cpu time
                //on large databases this can save hours
                temp[0] = ',';
    temp[1] = ' ';
    temp[2] = Month/10 + 0x30; //Tens
    temp[3] = Month%10 + 0x30; //units
    temp[4] = '/';
    temp[5] = Day/10 + 0x30;
    temp[6] = Day%10 + 0x30;
    temp[7] = '/';
    temp[8] = Year/1000 + 0x30;
    temp[9] = '0';
    temp[10] = (Year%100)/10 + 0x30;
    temp[11] = (Year%100)%10 + 0x30;
    temp[12] = ' ';
    temp[13] = Hour/10 + 0x30; //Tens
    temp[14] = Hour%10 + 0x30; //units
    temp[15] = ':';
    temp[16] = Minute/10 + 0x30;
    temp[17] = Minute%10 + 0x30;
    temp[18] = ':';
    temp[19] = Second/10 + 0x30;
    temp[20] = Second%10 + 0x30;
    temp[21] = '.';
    temp[22] = '0';
    temp[23] = '0';
    temp[24] = '0';
    temp[25] = ',';
    temp[26] = ' ';
    temp[27] = 0;  //Null termination

                //This is to save copying the string if it is the same
                if(oldQualityStatus != pSamples[loop].Quality.QualityStatus){
                    oldQualityStatus = pSamples[loop].Quality.QualityStatus;
        switch(pSamples[loop].Quality.QualityStatus)
        {
         case ihuOPCBad:
          strncpy(szQuality,"Bad",99);
          break;
         case ihuOPCUncertain:
          strncpy(szQuality,"Uncertain",99);
          break;
         case ihuOPCNA:
          strncpy(szQuality,"NotAvailable",99);
          break;
         case ihuOPCGood:
          strncpy(szQuality,"Good",99);
          break;
         default:
          strncpy(szQuality,"Really unknown",99);
          break;
        }
                }

    if ( pSamples[loop].ValueDataType == ihuFloat )
    {
                    //lengthOfActualSample = snprintf(ActualSample, 100,"%s%8.7f, %s, Type:Float\n",temp,pSamples[loop].Value.Float,szQuality);
                    lengthOfActualSample = snprintf(ActualSample, 100,"%s%8.7f, %s\n",temp,pSamples[loop].Value.Float,szQuality);
                    if(lengthOfActualSample < 0){
                         printf("ERROR WRITING TO BUFFER!\n");  
                    } else {
                        if(fwrite(ActualSample, 1, lengthOfActualSample, stream) < lengthOfActualSample){
                            printf("ERROR WRITING TO FILE!\n");
                        }
                    }
    }
    else if ( pSamples[loop].ValueDataType == ihuDoubleFloat )
    {
                    //lengthOfActualSample = snprintf(ActualSample, 100,"%s%8.15f, %s, Type: DoubleFloat\n ",temp,pSamples[loop].Value.DoubleFloat,szQuality);
                    lengthOfActualSample = snprintf(ActualSample, 100,"%s%8.15f, %s\n ",temp,pSamples[loop].Value.DoubleFloat,szQuality);
                    if(lengthOfActualSample < 0){
                         printf("ERROR WRITING TO BUFFER!\n");   
                    } else {
                        if(fwrite(ActualSample, 1,lengthOfActualSample, stream) < lengthOfActualSample){
                            printf("ERROR WRITING TO FILE!\n");
                        }
                    }

    }
    else if ( pSamples[loop].ValueDataType == ihuShort )
    {
                    //lengthOfActualSample = snprintf(ActualSample, 100,"%s%d, %s, Type:Short\n",temp,pSamples[loop].Value.Short,szQuality);
                    lengthOfActualSample = snprintf(ActualSample, 100,"%s%d, %s\n",temp,pSamples[loop].Value.Short,szQuality);
                    if(lengthOfActualSample <0){
                         printf("ERROR WRITING TO BUFFER!\n"); 
                    } else {
                        if(fwrite(ActualSample, 1, lengthOfActualSample, stream) < lengthOfActualSample){
                            printf("ERROR WRITING TO FILE!\n");
                        }
                    }
    }
    else if ( pSamples[loop].ValueDataType == ihuInteger )
    {
                    //lengthOfActualSample = snprintf(ActualSample, 100,"%s%d, %s, Type:Integer\n",temp, pSamples[loop].Value.Integer, szQuality);
                    lengthOfActualSample = snprintf(ActualSample, 100,"%s%d, %s\n",temp, pSamples[loop].Value.Integer, szQuality);
                    if(lengthOfActualSample < 0){
                         printf("ERROR WRITING TO BUFFER!\n");  
                    } else {
                        if(fwrite(ActualSample, 1, lengthOfActualSample, stream) < lengthOfActualSample){
                            printf("ERROR WRITING TO FILE! \n");
                        }
                    }

    }
    else if ( pSamples[loop].ValueDataType == ihuString )
    {
     //lengthOfActualSample = snprintf(ActualSample, 100,"%s%s, %s, Type:String\n",temp,pSamples[loop].Value.String,szQuality);
                    lengthOfActualSample = snprintf(ActualSample, 100,"%s%s, %s\n",temp,pSamples[loop].Value.String,szQuality);
                    if(lengthOfActualSample < 0){
                        printf("ERROR WRITING TO BUFFER!\n"); 
                    } else {
                        if(fwrite(ActualSample, 1, lengthOfActualSample, stream) < lengthOfActualSample){
                            printf("ERROR WRITING TO FILE! \n");
                        }
                    }
    }     
   }
  }
  lengthOfNumberOfSamples = snprintf(NumberOfSamples, 100,"Number of samples: %d\n",number_of_samples);
  if(lengthOfNumberOfSamples < 0){
            printf("ERROR WRITING TO BUFFER!\n"); 
        } else {
            if(fwrite(NumberOfSamples, 1, lengthOfNumberOfSamples, stream) < lengthOfNumberOfSamples){
                printf("ERROR WRITING TO FILE!\n");
            }
        }

      //timeDifference = GetTickCount() - timeDifference;
     //fprintf(stream, "Time taken: %d\n", timeDifference);
  // success or not you should free this
  FreeSamples(pSamples, number_of_samples);
  ihuFreePtr (pSamples);
  pSamples = NULL;
        timeTaken();
  fclose(stream);
 }


 return 0;
}

这里是该函数的精简版本，因此您不必阅读整个源代码，但是如果您愿意，它就在这里。我通过手动格式化字符串 (temp[]) 来优化代码，该字符串的运行速度提高了大约 40 倍，但它肯定是以 null 结尾的，因此这不应该成为问题。

   stream = fopen(outputFileName, "w");

   for(...){
     ... lots of conditions
     if ( pSamples[loop].ValueDataType == ihuFloat )
     {
          lengthOfActualSample = snprintf(ActualSample, 100,"%s%8.7f, %s\n",temp,pSamples[loop].Value.Float,szQuality);
          if(lengthOfActualSample < 0){
               printf("ERROR WRITING TO BUFFER!\n");  
          } else {
               if(fwrite(ActualSample, 1, lengthOfActualSample, stream) < lengthOfActualSample){
                    printf("ERROR WRITING TO FILE!\n");
               }
          }
      }
    }

    fclose(stream);

现在的结果：

Sample 81035, debug, 09/13/2010 11:10:55.000, 0.8900000, Good, Type:Float
Sample 81036, debug, 09/13/2010 11:11:00.000, 0.9500000, Good, Type:Float
Number of samples: 81037
**:56:15.000, 0.2800000, Good, Type:Float
Sample 80164, debug, 07/22/2010 15:56:20.000, 0.3400000, Good, Type:Float
Sample 80165, debug, 07/22/2010 15:56:30.000, 0.4100000, Good, Type:Float
... lots more samples
Sample 80322, debug, 08/01/2010 00:04:35.000, 0.5800000, Good, Type:Float
Sample 80323, debug, 08/01/2010 00:04:45.000, 0.6700000, Good, Type:Float
Sample 80324**
file ends here halfway through sample 80324

以粗体显示，您可以看到文件溢出的位置，并在最终调用 print("样本数：....) 之后继续将垃圾打印到文件中。

结果应该是这样的，并且在每台计算机上都是如此我已经在（4）上尝试过了，除了服务器，这是它必须工作的唯一电脑，

Sample 81035, debug, 09/13/2010 11:10:55.000, 0.8900000, Good, Type:Float
Sample 81036, debug, 09/13/2010 11:11:00.000, 0.9500000, Good, Type:Float
Number of samples: 81037

我非常想弄清楚这一点，并且完全不知道为什么会发生这种情况，有人有任何想法吗

？ gcc -Wall -Wformat 上的这些选项，我的整个项目中有零警告，我还使用 -pedantic 和

edit2 进行了编译：做了一个小得多的运行，而不是用数据溢出，而是

run1, 02/01/2010 08:50:50.000, 0.6000000, Good
run1, 02/01/2010 08:51:00.000, 0.6900000, Good
run1, 02/01/2010 08:51:10.000, 0.7600000, Good   #Sample505
Number of samples: 505
NULNULNULNULNULNULNULNULNULNULNULNULNULNULNULNULNULNULNULNUL (0 in a hex editor)

在运行时 用 0 或 NUL 溢出。变得大于大约 1000 时，它再次开始打印垃圾，但

run2, 03/31/2010 15:25:30.000, 0.8200000, Good
Number of samples: 1742
/22/2010 09:39:35.000, 0.5400000, Good
run2, 01/22/2010 09:39:45.000, 0.6400000, Good
run2, 01/22/2010 09:39:50.000, 0.6900000, Good

出于某种原因，2 次运行与 76660 的样本大小一致

run5, 12/31/2009 16:03:15.000, 0.6600000, Good
run5, 12/31/2009 16:03:25.000, 0.7600000, Good
Number of samples: 76660

，因此结果得出结论，<1000 打印 null 到文件末尾，在 1000 和 76660 之间，它打印垃圾，然后在样本中size 80234 还在文件末尾打印垃圾，这很奇怪，但多余的数据始终是一致的，并且如果运行多次则相同。

原文

Here is my code, basically one the 4 computer I have tested it on they all work perfectly with very large data sizes, eg textfiles up to 500mb in size, but when I run them on the server with real data even files as small as 6mb seem to overrun somewhere and writes garbage to the end of my files.

Here is the source of the entire function so people can have a more indepth look

/** Reads values from tagname between start_time and end_time which are strings in the format 
 of 01/01/1970-12:00, a null string is treated as 01/01/1970, values are stored in
 "tagname".csv */
int ReadValues(char * tagname, char * start_time, char * end_time, char * working_directory, char * new_tag_name)
{
 long lRet;
 int  number_of_samples;
 int     loop;
 IHU_DATA_SAMPLE  * pSamples=NULL;
 IHU_TIMESTAMP  StartTime;
 IHU_TIMESTAMP  EndTime;
 FILE *stream;
 char outputFileName[200];
 char szQuality[100];
 char    newTempTagName[100];
 int  Year;
 int  Month;
 int  Day;
 int  Hour;
 int  Minute;
 int  Second;
 long Subsecond;
 int date[10];

    //if we want to change the tagname do it now
 if(new_tag_name != 0){
       strncpy(newTempTagName, new_tag_name, 100);
    } else {
       strncpy(newTempTagName, tagname, 100);  
    } 

 // if the tagname contains a character that is invalid for a filename then we have to make a name
 if ( (strstr(newTempTagName, "/")) || (strstr(newTempTagName, "\\")) || (strstr(newTempTagName, ":")))
 {

  sprintf(outputFileName, "MadeUpTag%d", MadeUpTagCount++);
 }
 else
 {

        //If a working directory was passed in use it
        if(!working_directory){           
            strncpy(outputFileName, newTempTagName,199);   
            } else {
      strcpy(outputFileName, working_directory); //Copy the working directory to the filename
      // Append a / on the end of the working directory if it doesn't already have one
         if(outputFileName[strlen(outputFileName)-1] == '\"'){                   
                outputFileName[strlen(outputFileName)-1] = 0;
            } 
            if(outputFileName[strlen(outputFileName)-1] != '\\'){         
                strncat(outputFileName, "\\", 199);                                
            }
            strncat(outputFileName, newTempTagName, 199);   //Copy the tagname to the end of the working directory
        }

 }

 //Add the csv file extension
 strcat(outputFileName, ".csv");
 #ifdef DEBUG
 printf("Output filename: %s\n", outputFileName);
 #endif

 stream = fopen(outputFileName, "w");
 if( stream == NULL ) {
  printf("The file %s can not be opened\n", outputFileName );
 } else {

  //If start_time == 0 we want to start at 1970
  if(start_time == 0){
   // we want all the data so use an old start time
   struct tm local;
   local.tm_year = date[2] - 1900;
   local.tm_mon = date[1] - 1;
   local.tm_mday = date[0];
   local.tm_hour = date[3];
   local.tm_min = date[4];
   local.tm_sec = 0;
            time_t utc_seconds = mktime(&local);
   StartTime.Seconds = (long)utc_seconds;
            StartTime.Subseconds = 0; 

  } else {
            //we have been supplied a start time
   #ifdef DEBUG
            printf("Start Time: ");
   #endif
            lRet = convert_date(start_time, &StartTime);
   #ifdef DEBUG

   printf("Seconds %ld \n", StartTime.Seconds);
   #endif
  }

  //if end_time == 0 we want to go all the way until now.
  if(end_time == 0){
   // end time of 0 means now
   memset(&EndTime, 0, sizeof(EndTime));
  } else {
            //we have been supplied an end time
   #ifdef DEBUG
            printf("End Time: ");
   #endif
            lRet = convert_date(end_time, &EndTime);
   #ifdef DEBUG
            printf("Seconds %ld \n", EndTime.Seconds);
   #endif
  }

  // API will determine actual samples that are in that time range
  number_of_samples=0;

  // API will allocate the memory
  pSamples = NULL;
     //timeTaken();
  lRet = ihuReadRawDataByTime
  (
   serverhandle,  // the handle returned from the connect
   tagname,   // the single tagname to retrieve 
   &StartTime,   // start time for query
   &EndTime,   // end time for query
   &number_of_samples, // will be set by API
   &pSamples   // will be allocated and populated in the user API
  );

        char temp[100];
        char Header[100];
        char lengthOfHeader = 0;
        char SampleAndTag[100];
        int  lengthOfSampleAndTag = 0;
        char ActualSample[100];
        int  lengthOfActualSample = 0;
        char NumberOfSamples[100];
        int  lengthOfNumberOfSamples = 0;
  int  oldQualityStatus = 99999;

  if (lRet == ihuSTATUS_OK)
  { 

      // successful read
            lengthOfHeader = snprintf(Header, 100, "[Data]\nTagname,TimeStamp,Value,DataQuality\n");
            if(lengthOfHeader < 0){
                printf("ERROR WRITING TO BUFFER!\n");                                 
            } else {
                if(fwrite(Header, 1, lengthOfHeader, stream) < lengthOfHeader){
                        printf("ERROR WRITING TO FILE!\n");
                }
            }

   for (loop = 0;loop < number_of_samples;loop++)
   {
                struct tm * local;
                local = localtime(&pSamples[loop].TimeStamp.Seconds);
                Month = local->tm_mon + 1;
                Day = local->tm_mday;
                Year = local->tm_year + 1900;
                Hour = local->tm_hour;
                Minute = local->tm_min;
                Second = local->tm_sec;
                Subsecond = pSamples[loop].TimeStamp.Subseconds;

                //lengthOfSampleAndTag = snprintf(SampleAndTag, 100, "Sample %d, %s",loop, newTempTagName);
                lengthOfSampleAndTag = snprintf(SampleAndTag, 100, "%s", newTempTagName);
                if(lengthOfSampleAndTag < 0){
                   printf("ERROR WRITING TO BUFFER!\n");                                 
                } else {
                    if(fwrite(SampleAndTag, 1,lengthOfSampleAndTag, stream) < lengthOfSampleAndTag){
                        printf("ERROR WRITING TO FILE!\n");
                    }
                }

                //Doing the formatting ourselves manually per character saves about 20% of cpu time
                //on large databases this can save hours
                temp[0] = ',';
    temp[1] = ' ';
    temp[2] = Month/10 + 0x30; //Tens
    temp[3] = Month%10 + 0x30; //units
    temp[4] = '/';
    temp[5] = Day/10 + 0x30;
    temp[6] = Day%10 + 0x30;
    temp[7] = '/';
    temp[8] = Year/1000 + 0x30;
    temp[9] = '0';
    temp[10] = (Year%100)/10 + 0x30;
    temp[11] = (Year%100)%10 + 0x30;
    temp[12] = ' ';
    temp[13] = Hour/10 + 0x30; //Tens
    temp[14] = Hour%10 + 0x30; //units
    temp[15] = ':';
    temp[16] = Minute/10 + 0x30;
    temp[17] = Minute%10 + 0x30;
    temp[18] = ':';
    temp[19] = Second/10 + 0x30;
    temp[20] = Second%10 + 0x30;
    temp[21] = '.';
    temp[22] = '0';
    temp[23] = '0';
    temp[24] = '0';
    temp[25] = ',';
    temp[26] = ' ';
    temp[27] = 0;  //Null termination

                //This is to save copying the string if it is the same
                if(oldQualityStatus != pSamples[loop].Quality.QualityStatus){
                    oldQualityStatus = pSamples[loop].Quality.QualityStatus;
        switch(pSamples[loop].Quality.QualityStatus)
        {
         case ihuOPCBad:
          strncpy(szQuality,"Bad",99);
          break;
         case ihuOPCUncertain:
          strncpy(szQuality,"Uncertain",99);
          break;
         case ihuOPCNA:
          strncpy(szQuality,"NotAvailable",99);
          break;
         case ihuOPCGood:
          strncpy(szQuality,"Good",99);
          break;
         default:
          strncpy(szQuality,"Really unknown",99);
          break;
        }
                }

    if ( pSamples[loop].ValueDataType == ihuFloat )
    {
                    //lengthOfActualSample = snprintf(ActualSample, 100,"%s%8.7f, %s, Type:Float\n",temp,pSamples[loop].Value.Float,szQuality);
                    lengthOfActualSample = snprintf(ActualSample, 100,"%s%8.7f, %s\n",temp,pSamples[loop].Value.Float,szQuality);
                    if(lengthOfActualSample < 0){
                         printf("ERROR WRITING TO BUFFER!\n");  
                    } else {
                        if(fwrite(ActualSample, 1, lengthOfActualSample, stream) < lengthOfActualSample){
                            printf("ERROR WRITING TO FILE!\n");
                        }
                    }
    }
    else if ( pSamples[loop].ValueDataType == ihuDoubleFloat )
    {
                    //lengthOfActualSample = snprintf(ActualSample, 100,"%s%8.15f, %s, Type: DoubleFloat\n ",temp,pSamples[loop].Value.DoubleFloat,szQuality);
                    lengthOfActualSample = snprintf(ActualSample, 100,"%s%8.15f, %s\n ",temp,pSamples[loop].Value.DoubleFloat,szQuality);
                    if(lengthOfActualSample < 0){
                         printf("ERROR WRITING TO BUFFER!\n");   
                    } else {
                        if(fwrite(ActualSample, 1,lengthOfActualSample, stream) < lengthOfActualSample){
                            printf("ERROR WRITING TO FILE!\n");
                        }
                    }

    }
    else if ( pSamples[loop].ValueDataType == ihuShort )
    {
                    //lengthOfActualSample = snprintf(ActualSample, 100,"%s%d, %s, Type:Short\n",temp,pSamples[loop].Value.Short,szQuality);
                    lengthOfActualSample = snprintf(ActualSample, 100,"%s%d, %s\n",temp,pSamples[loop].Value.Short,szQuality);
                    if(lengthOfActualSample <0){
                         printf("ERROR WRITING TO BUFFER!\n"); 
                    } else {
                        if(fwrite(ActualSample, 1, lengthOfActualSample, stream) < lengthOfActualSample){
                            printf("ERROR WRITING TO FILE!\n");
                        }
                    }
    }
    else if ( pSamples[loop].ValueDataType == ihuInteger )
    {
                    //lengthOfActualSample = snprintf(ActualSample, 100,"%s%d, %s, Type:Integer\n",temp, pSamples[loop].Value.Integer, szQuality);
                    lengthOfActualSample = snprintf(ActualSample, 100,"%s%d, %s\n",temp, pSamples[loop].Value.Integer, szQuality);
                    if(lengthOfActualSample < 0){
                         printf("ERROR WRITING TO BUFFER!\n");  
                    } else {
                        if(fwrite(ActualSample, 1, lengthOfActualSample, stream) < lengthOfActualSample){
                            printf("ERROR WRITING TO FILE! \n");
                        }
                    }

    }
    else if ( pSamples[loop].ValueDataType == ihuString )
    {
     //lengthOfActualSample = snprintf(ActualSample, 100,"%s%s, %s, Type:String\n",temp,pSamples[loop].Value.String,szQuality);
                    lengthOfActualSample = snprintf(ActualSample, 100,"%s%s, %s\n",temp,pSamples[loop].Value.String,szQuality);
                    if(lengthOfActualSample < 0){
                        printf("ERROR WRITING TO BUFFER!\n"); 
                    } else {
                        if(fwrite(ActualSample, 1, lengthOfActualSample, stream) < lengthOfActualSample){
                            printf("ERROR WRITING TO FILE! \n");
                        }
                    }
    }     
   }
  }
  lengthOfNumberOfSamples = snprintf(NumberOfSamples, 100,"Number of samples: %d\n",number_of_samples);
  if(lengthOfNumberOfSamples < 0){
            printf("ERROR WRITING TO BUFFER!\n"); 
        } else {
            if(fwrite(NumberOfSamples, 1, lengthOfNumberOfSamples, stream) < lengthOfNumberOfSamples){
                printf("ERROR WRITING TO FILE!\n");
            }
        }

      //timeDifference = GetTickCount() - timeDifference;
     //fprintf(stream, "Time taken: %d\n", timeDifference);
  // success or not you should free this
  FreeSamples(pSamples, number_of_samples);
  ihuFreePtr (pSamples);
  pSamples = NULL;
        timeTaken();
  fclose(stream);
 }


 return 0;
}

Here is a cut down version of the function so you don't have tor ead the entire source, however if you want to it is here. Ive optimised the code by manually formatting the string (temp[]) which runs about 40x faster but it is definitely null terminated so this shouldn't be an issue.

   stream = fopen(outputFileName, "w");

   for(...){
     ... lots of conditions
     if ( pSamples[loop].ValueDataType == ihuFloat )
     {
          lengthOfActualSample = snprintf(ActualSample, 100,"%s%8.7f, %s\n",temp,pSamples[loop].Value.Float,szQuality);
          if(lengthOfActualSample < 0){
               printf("ERROR WRITING TO BUFFER!\n");  
          } else {
               if(fwrite(ActualSample, 1, lengthOfActualSample, stream) < lengthOfActualSample){
                    printf("ERROR WRITING TO FILE!\n");
               }
          }
      }
    }

    fclose(stream);

Now the results:

Sample 81035, debug, 09/13/2010 11:10:55.000, 0.8900000, Good, Type:Float
Sample 81036, debug, 09/13/2010 11:11:00.000, 0.9500000, Good, Type:Float
Number of samples: 81037
**:56:15.000, 0.2800000, Good, Type:Float
Sample 80164, debug, 07/22/2010 15:56:20.000, 0.3400000, Good, Type:Float
Sample 80165, debug, 07/22/2010 15:56:30.000, 0.4100000, Good, Type:Float
... lots more samples
Sample 80322, debug, 08/01/2010 00:04:35.000, 0.5800000, Good, Type:Float
Sample 80323, debug, 08/01/2010 00:04:45.000, 0.6700000, Good, Type:Float
Sample 80324**
file ends here halfway through sample 80324

In bold you can see where the file is overruning and continuing to print garbage to the file after the final call to print("number of samples: ....)

The results SHOULD be this and ARE on every single computer I've tried it on (4) except the server which is the only PC it has to work on.

Sample 81035, debug, 09/13/2010 11:10:55.000, 0.8900000, Good, Type:Float
Sample 81036, debug, 09/13/2010 11:11:00.000, 0.9500000, Good, Type:Float
Number of samples: 81037

I am desperate to figure this out and have absolutely no idea why this is happening, does anyone have any ideas?

edit: I have these options on gcc -Wall -Wformat and I have ZERO warnings in my entire project. I have also compiled with -pedantic and

edit2: did a much smaller run and instead of overrunning with data it overruns with 0s or NUL

run1, 02/01/2010 08:50:50.000, 0.6000000, Good
run1, 02/01/2010 08:51:00.000, 0.6900000, Good
run1, 02/01/2010 08:51:10.000, 0.7600000, Good   #Sample505
Number of samples: 505
NULNULNULNULNULNULNULNULNULNULNULNULNULNULNULNULNULNULNULNUL (0 in a hex editor)

As soon as the runs get bigger than around 1000 it starts printing garbage again though

run2, 03/31/2010 15:25:30.000, 0.8200000, Good
Number of samples: 1742
/22/2010 09:39:35.000, 0.5400000, Good
run2, 01/22/2010 09:39:45.000, 0.6400000, Good
run2, 01/22/2010 09:39:50.000, 0.6900000, Good

For some reason 2 runs worked consistently with sample size of 76660

run5, 12/31/2009 16:03:15.000, 0.6600000, Good
run5, 12/31/2009 16:03:25.000, 0.7600000, Good
Number of samples: 76660

So results conclude that <1000 prints nuls to the end of the file, between 1000 and 76660 it prints garbage and then at sample size 80234 also prints garbage at the end of the file, very odd but the excess data is always consistent and the same if run multiple times.

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爱的十字路口 2024-10-05 13:06:16

以下行使用无效的 fprintf 格式字符串：

fprintf(stream,"%s%8.15, %s, Type: DoubleFloat\n",temp,pSamples[loop].Value.DoubleFloat,szQuality)

具体来说，是 %8.15, 部分。您遗漏了类型说明符。如果您使用 gcc，则可以使用 -Wformat 选项让编译器检查您的 *printf 调用是否存在此类错误。

另外，我同意pmg的观点。您发布的代码似乎与您发布的输出不匹配。请仔细检查该代码是否正确。

The following line uses an invalid fprintf format string:

fprintf(stream,"%s%8.15, %s, Type: DoubleFloat\n",temp,pSamples[loop].Value.DoubleFloat,szQuality)

Specifically, the %8.15, part. You left out the type specifier. If you are using gcc, you can use the -Wformat option to have the compiler check your *printf calls for errors like this.

Also, I agree with pmg. The code you posted doesn't seem to match the output you posted. Please double-check that this is the correct code.

回复 原文
莫言歌 2024-10-05 13:06:16
 for (loop = 0;loop< number_of_samples;loop++){
                /* ... */
                if(fprintf(stream,"Sample %d, %s",loop, tagname) < 0){
                /* ... */
                    if(fprintf(stream,"%s%8.7f, %s, Type:Float\n",temp,pSamples[loop].Value.Float,szQuality) < 0){
                    /* ... */
                    if(fprintf(stream,"%s%s, %s, Type:String\n",temp,pSamples[loop].Value.String,szQuality) <0){
                    /* ... */
        if(fprintf(stream, "Number of samples: %d\n",number_of_samples) < 0){
        /* ... */

“类型：”输出在哪里？您正在查看正确的源文件吗？

 for (loop = 0;loop< number_of_samples;loop++){
                /* ... */
                if(fprintf(stream,"Sample %d, %s",loop, tagname) < 0){
                /* ... */
                    if(fprintf(stream,"%s%8.7f, %s, Type:Float\n",temp,pSamples[loop].Value.Float,szQuality) < 0){
                    /* ... */
                    if(fprintf(stream,"%s%s, %s, Type:String\n",temp,pSamples[loop].Value.String,szQuality) <0){
                    /* ... */
        if(fprintf(stream, "Number of samples: %d\n",number_of_samples) < 0){
        /* ... */

Where's the "Type:" output? Are you looking at the right source file?

回复 原文
笑看君怀她人 2024-10-05 13:06:16

我已经解决了我自己的问题！

我将代码从这样更改为：

FreeSamples(pSamples, number_of_samples);
ihuFreePtr (pSamples);
pSamples = NULL;
timeTaken();
fclose(stream);

由于

fclose(stream);
FreeSamples(pSamples, number_of_samples);
ihuFreePtr (pSamples);
pSamples = NULL;
timeTaken();

某种原因，我使用的用户 API 在释放内存时损坏了我的文件，我完全不知道如何或为什么，但确实如此。

and I have solved my own problem!

I changed the code from this:

FreeSamples(pSamples, number_of_samples);
ihuFreePtr (pSamples);
pSamples = NULL;
timeTaken();
fclose(stream);

To this:

fclose(stream);
FreeSamples(pSamples, number_of_samples);
ihuFreePtr (pSamples);
pSamples = NULL;
timeTaken();

For some reason the user API I was using was corrupting my file when it was freeing the memory, I have absolutely no idea how or why, but it was.

回复 原文
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