c language to read the form data (optimized version)

task

Excel table information into the program processing, enhanced versatility

Required

• c language runtime platform
• Data table, the format of FIG.

step

#define FILENAME "grade.csv"
#define TITLE1 "姓名"
#define TITLE2 "学号"
#define TITLE3  "成绩"
#define TITLE4 ""

#define HEADERMAXLEN 100 //表头最大字符总长
#define TITLEMAXLEN 100 //单个标题最大字符长度
#define TITLEMAXNUM 20 //标题最大数量
#define DATAMAXLEN 100 //数据最大字符总长

1. Read Header

FILE* fp;
fp = fopen(FILENAME, "r");
char* pHeader;
char* pTitle;

int colNum = 0;//记录表格数据列数
int* data2col;//记录需要的数据所在列
char csvHeader[HEADERMAXLEN];
char title[TITLEMAXNUM][TITLEMAXLEN];
char lineData[TITLEMAXNUM][DATAMAXLEN];
int readAll = 0;//判断是否到文件结尾

//读入表头信息
fscanf(fp, "%s", &csvHeader);
//分割表头各个标题
for (pHeader = csvHeader; *pHeader != '\0'; pHeader++)
{
  	colNum++;
  	pTitle = title[colNum];
  	while (*pHeader != ',' && *pHeader != '\0')
  	{
   		*pTitle++ = *pHeader++;
 	}
  	*pTitle = '\0';  
  	if (*pHeader == '\0')
   		break;
}
//优化有误，不可随意清除行数
/*
for (int i = colNum; i > 0; i--)
{
  	if (*title[i] == '\0')
   	colNum--;
  	else
  	{
   		for (int i = 1; i <= colNum; i++)
    			//cout << "第" << i << "列：" << title[i] << endl;
   		break;
  	}
   
}
*/

Optimizing Content:
The empty columns clear
knowledge induction:
string empty sentence repeated failures, finally adopted:

*title[i] == '\0'

• Content determined with the same string function strcmp (), with a =
  = array address comparison only
• Empty string "", the null character is '\ 0'

But the results of operational errors, react: not arbitrarily remove empty columns, since this is the csv format, so the ranks of the relationship between fixed and can not be changed due to the change in title, the following content, so cancel clearing empty columns, restored version

• Locate the required data

//标记数组置零
data2col = (int*)malloc(sizeof(int) * (TITLENUM +1));
for (int i = 1; i <= TITLENUM; i++)
{	
	data2col[i] = 0;
}
//找到所需数据对应列
for (int i = 1; i <= colNum; i++)
{
	if (strcmp(title[i], TITLE1) == 0)
  		data2col[1] = i;
  	if (strcmp(title[i], TITLE1) == 0)
    		data2col[2] = i;
	if (strcmp(title[i], TITLE1) == 0)
   		data2col[3] = i;
	if (strcmp(title[i], TITLE1) == 0)
    		data2col[4] = i;
} 

• Reads the required data

while (readAll == 0)
{
	//读入数据
	for (int i = 1; i <= colNum; i++)
	{
		if (readCell(fp, lineData[i]) == 0)
  		{
    			readAll = 1;
    			break;
   		}  
	}
	//可更改增加退出数据读入灵活性
	for (int i = 1; i <= TITLENUM; i++)
	{
		if (data2col[i]&&isEmpty(lineData[i]))
			readAll = 1；
	}
	//记录读入数据
	for (int i = 1; i <= colNum; i++)
	{
		if (i == data2col[1])
     			cout << TITLE1 << ": " << lineData[i] << " ";
    		if (i == data2col[2])
     			cout << TITLE2 << ": " << lineData[i] << " ";
    		if (i == data2col[3])
     			cout << TITLE3 << ": " << lineData[i] << " ";
    		if (i == data2col[4])
     			cout << TITLE4 << ": " << lineData[i] << " ";
	}
	cout << endl;
}

1. Empty string determination function

/****************************************
Function:判定字符串是否为空
Input:字符串
output:无
return:为空返回1，否则返回0
****************************************/
int isEmpty(char* s)
{
 	if (strcmp(s, "") == 0)
  		return 1;
	else
 		return 0;
}

2. Read the contents of a cell function

/****************************************
Function:读入一单元格内容
Input:数据所在文件
output:单元格内容
return:读入数据返回1，读至文件末尾返回0
****************************************/
int readCell(FILE* fp, char* s)
{
 	char temp[DATAMAXLEN],ch;
 	char *pTemp=temp;
 	if(!feof(fp))
 	if ((ch = fgetc(fp)) == '\n')
  	{
   		;
  	}
  	else if (ch == ',')
  	{
   		strcpy(s, "\0");
   		return 1;
  	}
  	else
   		*pTemp++ = ch; 
 
 	while (!feof(fp)&&(ch = fgetc(fp)) != ',' && ch != '\n')
 	{  
  		*pTemp++ = ch;
 	}
 	if (feof(fp))
  		return 0;
 	*pTemp = '\0';
 	strcpy(s, temp); 
 	return 1;
}

Results show

Written on the back

Having basic properties may be applied, if adjusted to the late complement on the basis of