从目录中读取多个文件？

Question

I am having difficulty to open files from a directory which is in different folder than the exe. I have managed to read one file. But how to read multiple files present in the directory in loop using program.

The code used for the single file processing is below:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main()
{
    FILE *fp, *tp, *tl;
    char str_buff[1024] = { FALSE };
    char str[125];
    char strlengths[MAX_NO_OF_STRINGS]= { FALSE };
    //int Result;
    //int string_startflag = FALSE;
    int string_cntr = FALSE,i = 0, n = 0;

    fp = fopen("D:/folder/language/stringEnglish.h", "r");
    tp = fopen("New Text Document.txt", "w"); // open the file to Write
    tl = fopen("New Length Document.txt", "w"); // open the file to Write lengths

    while (NULL != fgets(str_buff, sizeof(str_buff), fp))
    {
        sscanf(str_buff, "%*[^\"]%*c%[^\"]%*c%*[^\n]%*c", str);

        //printf("%s\n", str);

        if (string_cntr > 6)
        {
            if (string_cntr<= MAX_NO_OF_STRINGS)
            {
                fprintf(tp, "%s\n", str);
                strlengths[i] = strlen(str);
                i++;
            }
        }
        string_cntr++;
    }

    for(n=0;n<(MAX_NO_OF_STRINGS-6);n++)
    {
        fprintf(tl,"%d\n",strlengths[n]);
    }

    fclose(fp);
    fclose(tp);
    fclose(tl);

    return 0;
}

So I'm able to process file to parse the variables in the file and get the lengths of the strings. Problem is how to open multiple files I have file names in the folder language as:

stringItalian.h,stringLatvian.h,stringSlovakian.h,stringSlovenian.h,stringSpanish.h,stringSwedish.h,stringTurkish.h,stringUkrainian.h

How can I open files of these names in a loop?

Also is there any way to give the path of the folder D:/folder/language in general way?

Answer 1

You could pass the path as a command line argument into your program, reading its value from argv[1] if it is the first argument, then loop through the different files you want to read:

int main(int argc, char* argv[])
{
    ...
    const char* files[] = {"stringItalian.h", "stringLatvian.h",
                           "stringSlovakian.h", "stringSlovenian.h",
                           "stringSpanish.h", "stringSwedish.h",
                           "stringTurkish.h", "stringUkrainian.h"};
    int i;
    char fullpath[256];

    for (i=0; i<sizeof(files)/sizeof(files[0]); i++) {
        strcpy(fullpath, argv[1]);
        strcat(fullpath, files[i]);
        fp = fopen(fullpath, "r");

Answer 2

I recommend to start by putting the actual parsing of the file into a separate function, so you can call that function with only the file name.

The the simplest thing would be to have a table with the file names, and loop through this table giving the filenames to the function you just created.

Answer 3

You could rewrite the program by putting functionality inside a function say processFile(char *fileName) and then call the function with full path filenames eg

processFile("D:/folder/language/stringEnglish.h");
processFile("D:/folder/language/stringItalian.h");

Also you could put file names to process in a file and rewrite the program to loop over the lines in that file and call the function with filenames it finds.

Answer 4

As simonc has said you can give the path to the .h's via argv , but the problem is that this still requires that you know the names of the .h's at compile-time.

I assume that you want to loop over all .h's in a directory . There are libraries that let you do this cross-platform (search for these keywords), or you can do it dep on your OS:

• Linux: -> dirent

• Windows: FindFirstFile FindNextFile -> msdn

  (or, a little hackish but maybe a lot easier for you: first use system() to dir/ls *.h into a .txt file, then read that)