Question

* 我已经回答了我的问题，并且运行正常。有任何人有同样的问题，请参阅第二个答案部分。 *

我必须逐行读取一个文件，并将输出逐行存储在另一个文件中，但是我无法阅读所有的行，只读一行有三个记录。

或

请告诉我如何/何时使用ifstream/ofstream。 file*等代码中是否有任何错误。

但它不起作用。

//    initialization
int convertFileToSingleLine( char *p_record, char *sEor,long l); 
char sEor[25]={"& 0000200222! MB00200"}; //end of record
ofstream outdata;                         //is it legal to initialize this here???? 

int main()           
{

    outdata.open("output.txt", ios::app);  //output file

    ifstream infile;
    infile.open("sample.txt");            //inputfile

    FILE *p_record=NULL;
    char buf[4000];
    long int lineC;
    string line;

    while (getline(infile, line))
    {
        lineC++;
    }

    lineC = 3 * lineC - 2;                // every line has three records, first and            last are header and footer
    cout << lineC;                      //in my case file is having 20019 records     

    p_record = fopen("SWITCH.txt","r");      //input file for file pointer

    for(int l = 1; l <= lineC; l++)
    {
        while ((fgets(buf, sizeof buf, p_record)) != NULL)
        {
            convertFileToSingleLine(buf, sEor, lineC);
        }
    }

    fclose(p_record);
    return 0;
}



int convertFileToSingleLine(char *sInFile, char *sEor, long lC)    //convert into     single line
{

    //ofstream outdata;
    //outdata.open("output.txt", ios::app);

    char  sTemp[1087] = "\0"; 
    FILE *fpIn=NULL, *fpOut=NULL;
    static long int l = 0;
    char *ch = NULL; 
    char *ch1 = NULL;
    //int l=0;

    try
    {
        static int pos=0;
        int c;
        //outdata<<"HI TO";
        while(l!=lC)
        {  
            if( (ch=strstr(sInFile+pos, "001")) != NULL)
            {
                //if((ch1=strstr(ch, "& 00002! AB00200"))!=NULL)    
                //{
                strncpy(sTemp, ch, 1086);   //one record is 1086 charater long      
                //}
                pos = pos + 1086;   //move to next position in one line, by 1086 chacters.
                outdata << sTemp;

            }
        l++;

        }              
        return 0;           
    }
    catch(char *str1)
    {
        cout << "ERROR while opening" << sInFile << endl;
    }
    return 0;
}

它只读取一行，并且读取第一条记录两次，然后是第二条记录。我需要整个文件。我必须删除那些ifstream和ofstream，这是他们的另一种方式。

**sample file:**

{
three records in one line:
002 ahjfdghfuisyguigeuihgjkgfjkbjbgjbfggfdbjbhj & 00002! AB00200  001 uyrugjnbfhdgyudgfshdfj & 00002! AB00200    001 ytygfhvghghjbv uhruighvluhjkl heuifhuihfuh & 00002! AB00200

001 jhsdjkagfdsf .....
}

output:=>
{
001 uyrugjnbfhdgyudgfshdfj & 00002! AB00200  
001 uyrugjnbfhdgyudgfshdfj & 00002! AB00200
001 ytygfhvghghjbv uhruighvluhjkl heuifhuihfuh & 00002! AB00200
}

Answer 1

我解决了我的问题...... 现在我的文件正在被正确解析...

但我想。我应该在这里发布我的程序。

所以，你可以做到这一点。

using namespace std;

void convertFileToSingleLine( char *p_record, char *sEor,long l); 
char sEor[25]={"& 0000200222! MB00200"};
ofstream outdata;
static int pos=0;

int main()
{   
outdata.open("output.txt", ios::app);
ifstream infile;
infile.open("sample.txt");
FILE *p_record=NULL;
char buf[4000];         // char buffer to store one whole record             
long int lineC;
string line;

while (getline(infile, line))
{
lineC++;   // count the number of lines
}

cout<<lineC<<endl; //23066 lineC

p_record= fopen("sample.txt","r");
 while ((fgets(buf,sizeof buf, p_record)) != NULL)  // fetching one line in buf from file pointer p_record
    {       
    convertFileToSingleLine(buf, sEor, lineC); 
    }

fclose(p_record);
return 0;

}

void convertFileToSingleLine( char *sInFile, char *sEor, long lC)
{
ofstream outdata;
outdata.open("output.txt", ios::app);
char  sTemp[ 1087]="\0";
FILE *fpIn=NULL, *fpOut=NULL;
static int l=0;
char *ch = NULL; 
char *ch1 = NULL;
pos=0;

    int val;

try
{
    while(true)
    {  

        if( (ch=strstr(sInFile+pos, "001086")) != NULL)
        {               
            strncpy(sTemp, ch, 1086);           
        }
            pos=pos+1086;   
            outdata<<sTemp<<endl;
            if(pos>=3257)
            {
                break;
            }
    }

}
catch(char *str1)
{
    cout<<"ERROR while opening"<<sInFile<<endl;
}

}

我的文件大小为1GB。现在它被正确解析了。

  sample file:
{
three records in one line:
002 ahjfdghfuisyguigeuihgjkgfjkbjbgjbfggfdbjbhj & 00002! AB00200  001     uyrugjnbfhdgyudgfshdfj & 00002! AB00200    001 ytygfhvghghjbv uhruighvluhjkl heuifhuihfuh & 00002! AB00200   \\next line
001 jhdgfjksdkhv .... \\next line
001 jhsdjkagfdsf ..... \\next line
} //23066 lines in my one file, each having 3 records.

 output:=>
 {
 001 uyrugjnbfhdgyudgfshdfj & 00002! AB00200 \next line
 001 uyrugjnbfhdgyudgfshdfj & 00002! AB00200 \next line
 001 ytygfhvghghjbv uhruighvluhjkl heuifhuihfuh \next line
 001 jhdgfjksdkhv .... \\next line
 001 jhsdjkagfdsf ..... \\next line
 }  //69198 record i got in my outputfile.

无法通过文件指针逐行读取文件

1 个答案: