I've completed writing of counting words code finally. It counts total number of words in files. (i.e. txt). Now, I want to use multiple fork() to access and read every file. I studied in the last week. Besides, I use global variable to hold number of counted words. As far as I know, If I apply fork(), used global variables are assigned as 0. To avoid it, I tried to use mmap() and similar functions this is okey. But, I also want to use pipe() also (fifo() if it is possible) to communicate (hold values of numbers).
I use nftw() function to go in folders and files. My logic is on the below picture. How can use fork() and pipe() (fifo()) on this code ? fork() is really complicated for me because of my inexperience. I'm new using of pipe() and fork(). According to my idea logic of the code is that if I can use fork() and pipe(), there will be fork() every file(i.e. txt) and access them by using fork. If there is another folder and there are files, again creates fork() from one of created forks , then access file. I try to explain also drawing below. Thank you. I want to learn using of them.
int countInEveryFolder(const char *dir)
is used because I don't know how to count files until the next folder in nftw() function. Number of files is necessary because it is number of fork.
Every folder should be parent of files. The files are included by the folder.
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <dirent.h>
#include <errno.h>
#include <ftw.h>
#include <ctype.h>
#include <sys/mman.h>
#include <locale.h>
#include <errno.h>
#define MAX_PATH_LEN 2048
unsigned long total_words = 0UL;
unsigned long total_dirs = 0UL;
unsigned long total_files = 0UL;
// Just proves counting number of file in a folder
int countInEveryFolder(const char *dir) {
struct stat stDirInfo;
struct dirent * stFiles;
DIR * stDirIn;
char szFullName[MAX_PATH_LEN];
char szDirectory[MAX_PATH_LEN];
struct stat stFileInfo;
int numOfFile = 0;
strncpy( szDirectory, dir, MAX_PATH_LEN - 1 );
if (lstat( szDirectory, &stDirInfo) < 0)
{
perror (szDirectory);
return 0;
}
if (!S_ISDIR(stDirInfo.st_mode))
return 0;
if ((stDirIn = opendir( szDirectory)) == NULL)
{
perror( szDirectory );
return 0;
}
while (( stFiles = readdir(stDirIn)) != NULL)
{
if (!strcmp(stFiles->d_name, ".") || !strcmp(stFiles->d_name, ".."))
continue;
sprintf(szFullName, "%s/%s", szDirectory, stFiles -> d_name );
if (lstat(szFullName, &stFileInfo) < 0)
perror ( szFullName );
/* is the file a directory? */
if (S_ISREG(stFileInfo.st_mode))
{
printf( "Filename: %s\n", szFullName );
numOfFile++;
}
} // end while
closedir(stDirIn);
return numOfFile;
}
// Count words in files.
unsigned long count_words_in_file(const char *const filename)
{
unsigned long count = 0UL;
int errnum = 0;
int c;
FILE *in;
in = fopen(filename, "rt");
if (in == NULL) {
errnum = errno;
fprintf(stderr, "%s: %s.\n", filename, strerror(errnum));
errno = errnum;
return 0UL;
}
/* Skip leading whitespace. */
do {
c = getc(in);
} while (isspace(c));
/* Token loop. */
while (c != EOF) {
/* This token is a word, if it starts with a letter. */
if (isalpha(c))
count++;
/* Skip the rest of this token. */
while (!isspace(c) && c != EOF)
c = getc(in);
/* Skip the trailing whitespace. */
while (isspace(c))
c = getc(in);
}
/* Paranoid checking for I/O errors. */
if (!feof(in) || ferror(in)) {
fclose(in);
fprintf(stderr, "Warning: %s: %s.\n", filename, strerror(EIO));
errnum = EIO;
} else
if (fclose(in)) {
fprintf(stderr, "Warning: %s: %s.\n", filename, strerror(EIO));
errnum = EIO;
}
errno = errnum;
return count;
}
// Recursively go in folders
int nftw_callback(const char *filepath, const struct stat *sb, int typeflag, struct FTW *ftwbuf)
{
// Directory
if (typeflag == FTW_DP || typeflag == FTW_D)
{
total_dirs++;
printf("%*s%s\n", ftwbuf->level * 4, "", filepath);
//countInEveryFolder(filepath);
}
// Folder
else if (typeflag == FTW_F)
{
total_files++;
total_words += count_words_in_file(filepath);
printf("%*s%s\n", ftwbuf->level * 4, "", filepath);
}
return 0;
}
/* Error message */
void err_sys(const char *msg)
{
perror(msg);
fflush(stdout);
exit(EXIT_FAILURE);
}
int main(int argc, char *argv[])
{
total_files = total_dirs = total_words = 0UL;
if (nftw(argv[1], nftw_callback, 15, FTW_PHYS) == 0) {
/* Success! */
printf("%s: %lu files, %lu directories, %lu words total.\n",
argv[1], total_files, total_dirs, total_words);
} else {
/* Failed... */
err_sys("ntfw");
}
putchar('\n');
//printf( "\nTotal words = %d\n\n", *wordCount);
//printf( "\nTotal folders = %d\n\n", *folderCount);
//printf( "\nTotal childs = %d\n\n", *childCount); //fork()
return 0;
}
