Question

我以json格式将数据存储在文件中。当我尝试逐行读取并在缓冲区中对其进行细化处理然后进行解析时，它适用于某些行。但是当fgets（）读取不同长度的字符串时，它会无法解析。

它适用于几行。当字符串的长度改变时出现问题您会看到，键（数据字符串）中没有数据

输出是：

    {"line" : 0 ,"datastring" : "Jan 1 2017 00:00:00 75 822 96 548 85 76 82 93 78 82 64 89  899"}

    {"line" : 0 ,"datastring" : "Jan 1 2017 00:00:00 75 822 96 548 85 76 82 93 78 82 64 89 899"}

    {"line" : 0 ,"datastring" : "Jan 1 2017 00:00:00 75 822 96 548 85 76 82 93 78 82 64 89 899"}

    {"line" : 0 ,"datastring" : "Jan 1 2017 00:00:00 75 822"}

    {"line" : 0 ,"datastring" : ""}

    {"line" : 0 ,"datastring" : ""}

    {"line" : 0 ,"datastring" : ""}

    {"line" : 0 ,"datastring" : ""}

    00:00 75 822 96 548 85 76 82 93 78 82 64 89 899"}

    {"line" : 7 ,"datastring" : "Jan 1 2017 00:00:00 75 822"}

代码是：

#ifndef CPY_BUFF_SIZE
#define CPY_BUFF_SIZE       200
#endif

/* String conversion macro */
#define STR_(n)             #n
#define STR(n)              STR_(n)

/* Drive number used for FatFs */
#define DRIVE_NUM           0

const char inputfile[] = "fat:"STR(DRIVE_NUM)":input1.txt";
const char outputfile[] = "fat:"STR(DRIVE_NUM)":output.txt";
const char copyfile[] = "fat:"STR(DRIVE_NUM)":tempp.txt";

char    conbuff[100];

/* File name prefix for this filesystem for use with TI C RTS */
char fatfsPrefix[] = "fat";

char cpy_buff[CPY_BUFF_SIZE];
char mybuff[CPY_BUFF_SIZE];
char pub_buff[100];

int i=0,x,a,v,num_line=0;
uint16_t ret;
int filesize=0,fsize=0;
int buffsize,pos;
char text1[] = "Jan 1 2017 00:00:00 75 822 96 548 85 76 82 93 78 82 64 89 899";
char text2[] = "Jan 1 2017 00:00:00 75 822";

/*
 *  ======== mainThread ========
 *  Thread to perform a file copy
 *
 *  Thread tries to open an existing file inputfile[]. If the file doesn't
 *  exist, create one and write some known content into it.
 *  The contents of the inputfile[] are then copied to an output file
 *  outputfile[]. Once completed, the contents of the output file are
 *  printed onto the system console (stdout).
 */



void *mainThread(void *arg0)
{

    SDFatFS_Handle sdfatfsHandle;

    /* Variables for the CIO functions */
    FILE  *new;
    Json_Handle datalog;
    char *info = "{""\"line\":int32,""\"datastring\":string}";
    Json_createTemplate(&datalog, info,strlen(info));

    Json_Handle object;
    Json_createObject(&object, datalog, 1024);

  char *key1 = "\"line\"";
  char *key2 = "\"datastring\"";

  uint32_t value1 ;
  uint32_t o_value1 ;

  char value2[100];

  char o_value2[100];                    // output string
  char newbuff[100];


  uint32_t s_value=0 ;                       
  uint16_t value1_size = sizeof(value1);
  uint16_t value2_size = sizeof(value2);

  uint16_t builtBuffSize =sizeof(cpy_buff);



 /* Call driver init functions */

  SDFatFS_init();



    /* add_device() should be called once and is used for all media types */
    add_device(fatfsPrefix, _MSA, ffcio_open, ffcio_close, ffcio_read,
        ffcio_write, ffcio_lseek, ffcio_unlink, ffcio_rename);




    /* Mount and register the SD Card */
    sdfatfsHandle = SDFatFS_open(Board_SDFatFS0, DRIVE_NUM);
    if (sdfatfsHandle == NULL) {
        puts("Error starting the SD card\n");
        while (1);
    }
    else {
        puts( "Drive %u is mounted\n");
    }


    new=fopen(copyfile,"r+");

    fseek(new,0, SEEK_END);
    fsize=ftell(new);                       
    sprintf(conbuff,"size of file when opened in read and write mode=%d",fsize);
    puts(conbuff);

    rewind(new);

    if (!new) {
        strcpy(conbuff,"temp not opened");
        puts(conbuff);
    }



   for(v=0;v<8;v++)
   {
      memset(o_value2, 0, sizeof(o_value2));
       for(i=1;i<3;i++)
       {
         fgets(cpy_buff,sizeof(cpy_buff),new);
         strcat(mybuff,cpy_buff);
         memset(cpy_buff, 0, sizeof(cpy_buff));

       }

       x=strlen(mybuff);
       sprintf(conbuff,"len of my buff %d",x);
       puts(conbuff);



       sprintf(conbuff,"pointer loc=%d",ftell(new));

       Json_parse(object, mybuff, strlen(mybuff));
       sprintf(conbuff,"pos of new after reading buff  =%d",ftell(new));
       puts(conbuff);

       Json_getValue(object, key1, &o_value1, &value1_size);                 

       Json_getValue(object, key2, &o_value2, &value2_size);                

       memset(pub_buff, 0, sizeof(pub_buff));

       strcpy(pub_buff,o_value2);
       puts(pub_buff);

       puts("dsf");
       Json_setValue(object,key1,&s_value,value1_size);
       Json_setValue(object,key2,&o_value2,value2_size);



       Json_build(object,newbuff,&builtBuffSize);

       puts(newbuff);


       sprintf(conbuff,"pos of new before writing into file =%d",ftell(new));
       puts(conbuff);                                           //3

       fseek(new, -x, SEEK_CUR);
       sprintf(conbuff,"pos of new after setting to -x  =%d",ftell(new));
       puts(conbuff);

       fwrite(newbuff,1,strlen(newbuff),new);
       fputs("\r\n",new);

       sprintf(conbuff,"pos of new after writing into file =%d",ftell(new));
       puts(conbuff);

       fseek(new,0, SEEK_CUR);
       sprintf(conbuff,"pos of new after setting to 0  =%d",ftell(new));
       puts(conbuff);
       memset(mybuff, 0, sizeof(mybuff));


    }
    fseek(new,-1, SEEK_CUR);


 fclose(new);

    /* Close both inputfile[] and outputfile[] */
 strcpy(conbuff,"akjsdabsdas");
 puts(conbuff);


    /* Stopping the SDCard */
    SDFatFS_close(sdfatfsHandle);



    return (NULL);
}

如果更改大量数据，JSON不会从文件解析缓冲区

0 个答案: