#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define DATAFILE "data.dat"
#define TMPFILE "tmp.dat"
int InsertData(long code, long count)
{
FILE * pCur, * pTmp;
long lBarCode = 0;
long lCount = 0;
char bFound = 0;
char cmpRet = 0;
char * buf = NULL;
pCur = fopen(DATAFILE, "r");
pTmp = fopen(TMPFILE, "w");
while (!feof(pCur) && !bFound)
{
fscanf(pCur, "%ld, %ld /n", &lBarCode, &lCount);
if (lBarCode > code) //當前行比寫入行大
{
fprintf(pTmp, "%09ld, %ld /n", code, count); //寫入資料
fprintf(pTmp, "%09ld, %ld /n", lBarCode, lCount); //寫入原資料
bFound = 1;
}
else if (lBarCode == code) //當前行與寫入行一樣
{
fprintf(pTmp, "%09ld, %ld /n", code, count); //寫入資料即替換原來的
bFound = 1;
}
else //當前行比寫入行小
{
fprintf(pTmp, "%09ld, %ld /n", lBarCode, lCount); //寫入原資料
}
}
if (bFound) //如果找到了把原檔案後面的內容拷貝到臨時檔案裡
{
buf = malloc(1024);
while (!feof(pCur))
{
lCount = fread(buf, 1, 1024, pCur);
fwrite(buf, 1, lCount, pTmp);
}
}
else //沒找到的話就寫在最後面
{
fprintf(pTmp, "%09ld, %ld /n", code, count); //寫入資料
}
fclose(pCur);
fclose(pTmp);
remove(DATAFILE); //刪除原檔案,改檔案名稱
rename(TMPFILE, DATAFILE);
free(buf);
return 0;
}
int main(void)
{
InsertData(1, 5);
InsertData(23, 6);
InsertData(80, 9);
InsertData(255, 2);
InsertData(80, 10);
return 0;
}