How to compare two files line by line after storing them in vector

Question

0.00/5 (No votes)

See more:

i have two text files named totalfiles.txt and uploaded.txt i am storing both of them in a vector now offcourse when this program will run for a very first time uploaded.txt will be made and it will be empty and first file will be written in it after its successfully uploaded to the server what i want is some kind of method to compare both .txt files so if files that are already uploaded to server don't get uploaded again so is there any method to do that in c++? again at the beginning i am going to store the files in vector and i need to do above operation via vector and not using .txt files directly with fstream

What I have tried:

ifstream read2("ScannedFiles.txt");
	ofstream read3("Problem.txt", ios::app);
	fstream uploaded("Uploaded.txt", ios::app);
	vector<string>filen2;
	vector<string>upl;
	string st3;
	string st2;
	while (getline(read2, st2))
	{
		if (st2.size() > 0)
			filen2.push_back(st2);
		else
			break;

	}
	while (getline(uploaded,st3))
	{
		if (st3.size() > 0)
			upl.push_back(st3);
		else
			break;
	}
<pre>	for (vector<string>::iterator t = filen2.begin(); t != filen2.end(); t++)

Posted 28-Feb-20 7:46am

Member 12899279

Updated 29-Feb-20 0:51am

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Answer 1 · 2020-02-28T08:03:00

Solution 1

Start with the easy route: calculate a hash code for the whole of each file, and store it with the file. (MD5 is technically broken, but for a non-security application it's faster than SHA - I'd probably use that).
Then when the file upload happens, calculate it's hash code, and compare it with your collection of existing ones. If it isn't there, it's genuinely new. If it is, the chances are that files there already (MD5/SHA hash collision are pretty rare, but you can then do an exhaustive comparison with a much, much, more limited number of matching files to check character by character)

Posted 28-Feb-20 8:03am

OriginalGriff

Comments

Member 12899279 28-Feb-20 14:32pm

i am storing complete file path of the file i am uploading in the uploaded.txt so all it has to do is that to check next time before uploading by matching the path from totalfiles.txt with uploaded.txt if it finds it in uploaded.txt then leave it and not upload otherwise upload it

this is asn eg

totalfiles.txt have following files:-

C:\Program Files\Android\Android Studio\bin\lldb\lib\plat-irix5\readcd.doc
C:\Program Files\Android\Android Studio\bin\lldb\lib\plat-irix6\readcd.doc
C:\Program Files\JetBrains\PyCharm Community Edition 2019.2.3\help\ReferenceCard.pdf
C:\Program Files\JetBrains\PyCharm Community Edition 2019.2.3\help\ReferenceCardForMac.pdf
C:\Program Files\NetBeans 8.0.2\nb\shortcuts_mac.pdf

uploadedFiles.txt have following files:-

C:\Program Files\Android\Android Studio\bin\lldb\lib\plat-irix6\readcd.doc
C:\Program Files\JetBrains\PyCharm Community Edition 2019.2.3\help\ReferenceCard.pdf

Now all it has to do before uploading is to check if any of the lines are already present in uploadedfiles.txt then dont upload otherwise upload

Stefan_Lang 3-Mar-20 5:05am

Where's the point of downloading the uploaded file for comparison just to prevent an unnecessary uploading? You're not reducing network traffic in this manner - on the contrary, you'd increase it!

The solution makes a very reasonable suggestion: rather than comparing the entire files, store a hash with each file, and only compare the hashes. That way you only have to download the hash of the uploaded file for testing. Is that not what you want?

Stefan_Lang 3-Mar-20 5:06am

Very reasonable suggestion. Have a 5.

Member 12899279 · Answer 2 · 2020-02-29T00:52:00

i think i figured it out below is the code

string hashi ="files";
ifstream read2("ScannedFiles.txt");
ofstream read3("Problem.txt", ios::app);
/// ofstream read4("Uploaded.txt", ios::app);
vector<string>filen2;
string st2;
while (getline(read2, st2))
{
if (st2.size() > 0)
filen2.push_back(st2);
else
break;

}
read2.close();
int a = filen2.size();
int b = a;
int h = 1;
for (vector<string>::iterator t = filen2.begin(); t != filen2.end(); t++)
{
string st3;
vector<string>upl;
ifstream uploaded("Uploaded.txt", ios::app);
while (getline(uploaded, st3))
{
if (st3.size() > 0)
upl.push_back(st3);
else
break;
}
uploaded.close();
int c = upl.size();

int i = 0;

string currfil = t[i];
string name = getFileName(currfil);
bool toWrite = true;

for (vector<string>::iterator t2 = upl.begin(); t2 != upl.end(); t2++)
{
int j = 0;
if (c <= 0)
break;
else
{
if (t2[j] == currfil)
{

toWrite = false;
}
}
}
if (toWrite == true)
{


CURL *curl;
CURLcode res;

curl_httppost* post = NULL;
curl_httppost* last = NULL;
/*HttpPost* post = NULL;
HttpPost* last = NULL;*/
//string name = "CV.pdf";
//string path = "E:\\BIMS Uni\\CV.pdf";
//string name = getFileName(path);
// string request = "Md5=" + hashi;
curl = curl_easy_init();
if (curl)
{
// curl_easy_setopt(curl, CURLOPT_POSTFIELDS, request.c_str());
curl_formadd(&post, &last,
CURLFORM_COPYNAME, "Md5",
CURLFORM_COPYCONTENTS, hashi.c_str(),
CURLFORM_END);
curl_formadd(&post, &last,
CURLFORM_COPYNAME, "name2",
CURLFORM_COPYCONTENTS, name.c_str(),
CURLFORM_END);
curl_formadd(&post, &last,
CURLFORM_COPYNAME, "file2",
CURLFORM_FILE, currfil.c_str(),
CURLFORM_END);



curl_easy_setopt(curl, CURLOPT_URL, "http://localhost:8081/PCInfo/test.php");

curl_easy_setopt(curl, CURLOPT_HTTPPOST, post);
curl_easy_setopt(curl, CURLOPT_TIMEOUT, 20L);


res = curl_easy_perform(curl);
if (res == 28)
{
read3 << currfil << endl;
//h = h + 1;

}
if (res == 26)
{
//return 0;
read3 << currfil << endl;
//h = h + 1;

}
if (res == 0)
{
// uploaded.close();
ofstream uploaded("Uploaded.txt", ios::app);
uploaded << currfil << endl;
uploaded.close();
}

curl_formfree(post);
}
/*else
{
return 0;
}*/

curl_easy_cleanup(curl);
}
}
return 0;
i am still looking for a more better and clean way because i think it will take too much time