Recursive Directories and File streaming and Searching Strings - c++

Question

I have an issue with the recursive call in the walkThroughFunction.
The code is supposed to go through directories and count the sub directories and if it finds a file it should open it and search a certain string.
The code only goes through one directory. Can someone help me with this. You will find the braces misplaced a little. Kindly ignore those.
int directories=0;
void walkThroughDirectory(char *directory_name,char *searchString){
DIR * directory;
struct dirent * walker;
char d_name[PATH_MAX];
int path_length;
char path[PATH_MAX];
directory=opendir(directory_name);
if(directory==NULL){
cout<<"Error"<<endl;
cout<<directory_name<<" Cannot be Opened"<<endl;
exit(10000);
}
while((walker=readdir(directory)) !=NULL){
strcpy(d_name,walker->d_name);
cout<<directory_name<<"/"<<endl;
if (strcmp (d_name, "..") == 0 &&
strcmp (d_name, ".") == 0){
continue;
}
else{
path_length = snprintf(path,PATH_MAX,"%s/%s\n",directory_name,d_name);
cout<<"HELLO"<<endl;
cout<<path<<endl;
if (path_length >= PATH_MAX){
cout<<"Path is too long"<<endl;
exit (1000);
}
if(walker->d_type==DT_DIR){
cout<<"Hello"<<endl;
directories++;
walkThroughDirectory (path,searchString);
}
else if(walker->d_type==DT_REG){
ifstream openFile;
openFile.open(path);
char line[1500];
int currentLine = 0;
if (openFile.is_open()){
while (openFile.good()){
currentLine++;
openFile.getline(line, 1500);
if (strstr(line, searchString) != NULL)
cout<<path<<": "<<currentLine<<": "<<line<<endl;
}
}
openFile.close();
}
/*
struct stat directory_stat;
if (stat(path, &directory_stat) == -1){
return;
}
if (S_ISDIR(directory_stat.st_mode)){
cout<<"HELLO"<<endl;
directories++;
walkThroughDirectory(path, searchString);
}
else if (S_ISREG(directory_stat.st_mode)){
ifstream openFile;
openFile.open(path);
char line[1500];
int currentLine = 0;
if (openFile.is_open()){
while (openFile.good()){
currentLine++;
openFile.getline(line, 1500);
if (strstr(line, searchString) != NULL)
cout<<path<<": "<<currentLine<<": "<<line<<endl;
}
}
// it's a file so search for text in file
}
*/
}
}
if (closedir (directory))
{
cout<<"Unable to close "<<directory_name<<endl;
exit (1000);
}
}
int main(){
char * name;
name=new char;
cout<<"Total Directories "<< directories<<endl;
name=get_current_dir_name();
cout<<"Current Directory is: "<<name<<endl;
/*
cout<<"Now Enter The Desired Directory from the root or the current path"<<endl;
char *desiredDirectory;
desiredDirectory=new char;
cin>>desiredDirectory;
cout<<"Enter The String You want to search"<<endl;
char *searchString;
searchString=new char;
cin>>searchString;
*/
char ourpath[400];
strcpy(ourpath,name);
walkThroughDirectory(ourpath,"diminutive");
cout<<"Total Directories "<< directories<<endl;
return 0;
}

Answer 1

This code has several problems. First, when you perform the strcmp to check if d_name is "." or "..", you need to use an OR, not an AND. Second, when you call sprintf to create your c-string path, you should not have a newline at the end of the string. This is what was causing your code to only go one level deep. Third, when you call get_current_dir_name, it does all the malloc work for you. What you're doing is allocating space for a single char, which won't work in itself and is not a correct use of the API. See the man page for get_current_dir_name.
The below code addresses these issues (and also has proper indentation).
#include <iostream>
#include <fstream>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include <limits.h>
#include <string.h>
int directories=0;
void walkThroughDirectory(char *directory_name,char *searchString)
{
DIR *directory;
struct dirent *walker;
char d_name[PATH_MAX];
int path_length;
char path[PATH_MAX];
directory = opendir(directory_name);
if(directory == NULL)
{
std::cout << directory_name << " Cannot be Opened" << std::endl;
exit(1);
}
while((walker=readdir(directory)) != NULL)
{
strcpy(d_name, walker->d_name);
// Needs to be || not &&
if (strcmp(d_name, "..") == 0 || strcmp(d_name, ".") == 0)
{
continue;
}
else
{
// No newline on the path name.
path_length = snprintf(path, PATH_MAX, "%s/%s", directory_name, d_name);
if (path_length >= PATH_MAX)
{
std::cout << "Path is too long" << std::endl;
exit(2);
}
if(walker->d_type == DT_DIR)
{
directories++;
walkThroughDirectory(path, searchString);
}
else if(walker->d_type==DT_REG)
{
std::ifstream openFile;
openFile.open(path);
char line[1500];
int currentLine = 0;
if (openFile.is_open())
{
while (openFile.good())
{
currentLine++;
openFile.getline(line, 1500);
if (strstr(line, searchString) != NULL)
std::cout << path << ": " << currentLine << ": " << line << std::endl;
}
}
openFile.close();
}
}
}
if (closedir(directory))
{
std::cout << "Unable to close " << directory_name << std::endl;
exit(3);
}
}
int main()
{
// get_current_dir_name() mallocs a string for you.
char *name;
name = get_current_dir_name();
walkThroughDirectory(name, "matthew");
free(name);
std::cout << "Total Directories: " << directories << std::endl;
return 0;
}