C++ how to open multiple text files for manipulation?

Question

what i want to do is read in a text file at a time do some manipulation to it, then close and open another one and so on...

assuming that there are hundreds of files with different names, how can i attain a list of the text file names and then run them all

any sample code with explanation would really help thanks !

Answer 1

Hi

Assuming that the files have a common extension ( .txt)

You could write a temporary file with the files listed and then open each one like this:

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

const char* tmpfl = "tmpfile";

int main()

{

   char cmd[21];

   char File[20];

   char Line[80];

   char txfile[80];

   FILE* fp;

   FILE* fp1;

   strcpy(cmd,"ls *.txt > ");

   strcat(cmd,tmpfl);

   //printf("cmd is %s\n",cmd);

   system(cmd);

   if (( fp = fopen(tmpfl,"r")) == NULL)

   {

      printf("Cannot open temporary file!\n");

      exit(1);

   }

   while ( fgets ( File ,sizeof(File),fp))

   {

       strcpy(txfile,"./");

       strcat(txfile,File);

       printf("File: %s",txfile);

       if (( fp1 = fopen(txfile,"r")) == NULL)

       {

          printf("Cannot open %s\n",txfile);

          continue;

       }

       while ( fgets ( Line , sizeof(Line), fp1) == NULL)

       {

          // Do something here

       }

       fclose(fp1);

   }

   fclose(fp);

   return 0;

}

This is 'C' sorry, but it shold give you some ideas

Regards

G

Answer 2

If you're using Visual Studio, look at this:

http://msdn.microsoft.com/en-us/library/...

Specifically, FindFirstFile, FindNextFile, etc.