当要写入txt的输入数据大于16kb (C编程)时，应用程序崩溃

Question

我正试图制作一个程序，从txt文件(坐标x1,x2)中获取输入，并将其存储在元素上以SVG格式编写。我在下面写的代码实际上是有效的。问题是当我得到大于16kb的输入时，在编写svg文件时应用程序崩溃。所以我找不到问题所在。它应该是关于"strcat(str_joined, svg[i].xy);"这是因为我将这么多字符串连接到一个字符串变量中。

输入示例:

339, 52
339, 52
339, 52
338, 53
338, 53
337, 54
337, 54
337, 54
337, 55
337, 55
336, 56
336, 56
336, 56
336, 57
335, 57
335, 56
334, 56
334, 56
333, 56
332, 56
332, 56
331, 56
331, 56
330, 56
330, 56
329, 56

输出示例:<svg><polyline points='339,52 339,52 339,52 338,53 338,53 337,54 '/></svg>

和代码:我只是把generate_svg部分的代码。

void generate_svg(char *input, char *output)
{         
    //INPUT OPERATİONS //
FILE *fp;
int array_size = 0, i=0, max_lines = 0;  // Line counters
char c;  // To store a character read from file to check whether newline or not
char *str_joined = NULL;
// Open the file
fp = fopen(input, "r");
//Count the number of lines for the array size 
for (c = getc(fp); c != EOF; c = getc(fp))
    if (c == 'n') 
        array_size = array_size + 1;
fclose(fp);

// read the file into an array of coordinates
Coord *coord = malloc(array_size * sizeof *coord); //preallocation for performance
fp = fopen(input, "r");
while(!feof(fp))
{
   //check whether input getting correctly             
   if(fscanf(fp, "%d, %d", &coord[i].x, &coord[i].y)==2)      
      i++;           
}
fclose(fp);
//OUTPUT OPERATIONS
max_lines = i;
SVG *svg = malloc(array_size * sizeof *svg); // allocate memory
size_t total_length=0, length=0; //total length and length of string
for(i=0; i<max_lines; i++)
{
    sprintf(svg[i].xy , "%d,%d ", coord[i].x, coord[i].y);
    total_length += strlen(svg[i].xy); 
    //printf("%sn", svg[i].xy);
}
str_joined = (char*)malloc(total_length * sizeof *str_joined); // allocate memory for joined strings
str_joined[0] = ''; // empty string we can append to
for(i=0; i<max_lines; i++)
{
         strcat(str_joined, svg[i].xy);
         length = strlen(str_joined);
         str_joined[length+1] = '';           /* followed by terminator */
}
FILE *fp_out;
fp_out = fopen(output,"w+"); //erase the content and write on it if exists or create the file and write on it
if(fp_out == NULL)
{
  printf("Error");           
}
else
{
  fprintf(fp_out, "<svg><polyline points='%s'/></svg>" , str_joined);
   printf("Operation successful.n");
}
//printf("%sn", str_joined);

}

所以任何帮助都会很感激。提前谢谢。

//更新头:

//definitions
#define MAX_FILE_NAME 100
#define OUTPUT_FILE_NAME "svg_output.svg"
void generate_svg(char *input, char *output);
//storage for coordinates
typedef struct Coord
{
    int x;
    int y;
}Coord;
typedef struct SVG
{
  char xy[20];        
}SVG;

应用程序崩溃图片:

Answer 1

好的，真的谢谢你的帮助。我解决了这个问题。我将Visual Studio配置为C编译，并将我的代码标准化为C99。所以我的代码的最终形状如下，它工作。

void generate_svg(char *input, char *output)
{
    //INPUT OPERATİONS //
    FILE *fp, *fp_out;  SVG *svg;  Coord *coord;
    int array_size = 0, i=0, max_lines = 0;  // Line counters
    char c;  // To store a character read from file to check whether newline or not
    char *str_joined = NULL;
    size_t total_length=0, length=0;
    // Open the file
    fp = fopen(input, "r");
    if (fp == NULL)
    {
        perror("Error");
    }
    else
    {
         //Count the number of lines for the array size 
        for (c = getc(fp); c != EOF; c = getc(fp))
            if (c == 'n') 
                array_size = array_size + 1;
        fclose(fp);
    }


    // read the file into an array of coordinates
    coord = (Coord*)malloc(array_size * sizeof(Coord)); //preallocation for performance
    fp = fopen(input, "r");
    if (fp == NULL)
    {
        perror("Error");
    }
    else
    {
        while(!feof(fp))
        {
           //check whether input getting correctly             
           if(fscanf(fp, "%d, %d", &coord[i].x, &coord[i].y)==2)      
              i++;           
        }
        fclose(fp);
    }

    //OUTPUT OPERATIONS
    max_lines = i;
    svg = (SVG*)malloc(array_size * sizeof(SVG)); // allocate memory
     //total length and length of string
    for(i=0; i<max_lines; i++)
    {
        sprintf(svg[i].xy , "%d,%d ", coord[i].x, coord[i].y);
        total_length += strlen(svg[i].xy); 
        //printf("%sn", svg[i].xy);
    }
    str_joined = (char*)malloc(total_length * 2); // allocate memory for joined strings
    str_joined[0] = ''; // empty string we can append to
    for(i=0; i<max_lines; i++)
    {
        strcat(str_joined, svg[i].xy);
    }
    fp_out = fopen(output,"w+"); //erase the content and write on it if exists or create the file and write on it
    if (fp_out==NULL)
    {
        perror("Error");
    }
    else
    {
        fprintf(fp_out, "<svg><polyline points='%s'/></svg>" , str_joined);
        printf("Operation successful.n");
    }

    //printf("%sn", str_joined);


}