Merge files from /etc to one file using C

Applications Programming
1

Hi guys,

I have a question which might be easy to answer but I don't how to do it.
The thing is I need to make a program in C which creates a file with all the content from the files in \etc.
I'm not new to C language but to UNIX.

I've read somewhere I need to use functions like f_read f_write for files but I don't know how to traverse the directory and append the each file's info in the new file.

thank you in advance!! :slight_smile:

Sussie

2

No so a "dummies" question...
Moved to more suitable forum: programming

3

So if anyone is interested about how it can be done, this works (more or less) but of course the code could be optimized.

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/types.h>
#include <fcntl.h>
#include <sys/stat.h>

void listar(char *dir);

int main(int argc, char *argv[]){
	int dscr1, dscr2, i;
	char Buffer[512];
	dscr2 = creat("file.txt", 0666);
	DIR *d;
	struct dirent *ent;
	struct stat inode;
	if((d = opendir("/etc")) == NULL){
		printf("Couldn't open");
		perror("\etc");
		exit(1);
	}
	printf("\n");
	chdir("/etc");
	while(ent = readdir(d)){
		if((strncmp(".", ent->d_name) != 0) && (strncmp("..", ent->d_name) != 0)){
			lstat(ent->d_name, &inode);
			if(S_ISREG(inode.st_mode)){
				printf("%s\n", ent->d_name);
				if((dscr1 = open(ent->d_name, O_RDONLY)) == -1){
			                perror("ERROR");
					close(dscr1);
			                continue;
			        }
			        while (read(dscr1, &Buffer, 512)){
			                write(dscr2, Buffer, sizeof(Buffer));
			        }
				for(i = 0; i < 512; i++){
					Buffer = ' ';
                                }
				close(dscr1);
			}
		}
	}
	printf("\n");
        close(dscr2);

	return 0;
}