Unable to read each word in a text file - c++

I have got a text file with contents:
Artificial neural networks (ANNs) or connectionist systems are
computing systems vaguely inspired by the biological neural networks
that constitute animal brains.[1] Such systems "learn" (i.e.
progressively improve performance on) tasks by considering examples,
generally without task-specific programming. For example, in image
recognition, they might learn to identify images that contain cats by
analyzing example images that have been manually labeled as "cat" or
"no cat" and using the results to identify cats in other images. They
do this without any a priori knowledge about cats, e.g., that they
have fur, tails, whiskers and cat-like faces. Instead, they evolve
their own set of relevant characteristics from the learning material
that they process.
and I'm using this code to read the contents.
ifstream file("/Users/sourav/Desktop/stl/stl/stl/testdata.txt");
while (! file.eof()) {
string word;
file >> word ;
cout << word << "\n";
}
This is the first few lines of output:
Artificial
neural
(ANNs)
are
vaguely
and if you notice that the contents are not read properly. I don't see or connectionist systems are computing systems.
I'm missing few string values from the text file while reading it.
Note:I'm using Xcode.
ifstream file("/Users/sourav/Desktop/stl/stl/stl/dictionary.txt");
string line;
if (file.is_open()) // same as: if (myfile.good())
{
while(getline(file,line,'\r')){
transform(line.begin(), line.end(), line.begin(), ::tolower);
Dictionary.insert(line);
}
cout<<Dictionary.size()<<" words read from dictionary\n";
file.close();
Why does the dictionary.size() change in value when I transform it to lowercase

While this may not explain why it does not work, your code may look like:
ifstream file("testdata.txt");
do {
string word;
file >> word ;
if (!file.good()) break;
cout << word << "\n";
} while (!file.eof());
It is not correct to test for eof condition if you never tried to read something first.
This code (and yours while being logically incorrect) works perfectly. So something else is happening (that is not related to xcode).

Try using something along the lines of this:
ifstream file("/Users/sourav/Desktop/stl/stl/stl/testdata.txt");
string word;
while(file >> word) //While there is a word to get... get it and put it in word
{
cout << word <<"\n";
}
A little bit more of an explanation can be found on the accepted answer in question read word by word from file in C++
I don't see much of a difference in logic though between this and your logic.

Related

Issue in Loop with Reading and Writing from File c++

The problem I'm having is that in the following loop, I'm attempting to read sentences one by one from the input file (inSentences) and output it into another file (outMatch), if it contains a certain word. I am not allowed to use any string functions except for .at() and .size().
The problem lies in that I'm trying to output the sentence first into a intermediary file and then use the extraction operator to get the word one by one to see if it has the word. If it does, it outputs the sentence into the outMatch file. While debugging I found that the sentence variable receives all of the sentences one by one, but the sentMore variable is always extracting out the first sentence of the file, so it's not able to test the rest of the sentences. I can't seem to fix this bug. Help would be greatly appreciated.
P.S. I don't really want the answer fleshed out, just a nudge or a clue in the right direction.
outMatch.open("match");
outTemp.open("temp");
while(getline(inSentences, sentence, '.')){
outTemp << sentence;
outTemp.close();
inTemp.open("temp");
while(inTemp >> sentMore){
if(sentMore == word){
cout << sentence << "." << endl;
inTemp.close();
sentCount++;
}
}
}
You should use string streams! Your issue right now appears to be that you never reopen outTemp, so after the first loop you're trying to write to it after you've closed it. But you can avoid all these problems by switching to stringstreams!
Since you don't want a full solution, an example may look like:
string line_of_text, word;
istringstream strm(line_of_text);
while(strm >> word) {
cout << word << ' ';
}

I filed my vector from a text file and it wont cout as one line. How can I do this?

Long story short I need my vector to cout as a single line without creating its own new lines for my program to work correctly. the text file i read into the vector was
laptop#a small computer that fits on your lap#
helmet#protective gear for your head#
couch#what I am sitting on#
cigarette#smoke these for nicotine#
binary#ones and zeros#
motorcycle#two wheeled motorized bike#
oj#orange juice#
test#this is a test#
filled the vector using the loop:
if(myFile.is_open())
{
while(getline(myFile, line, '#'))
{
wordVec.push_back(line);
}
cout << "words added.\n";
}
and printed it using this:
for(int i = 0; i < wordVec.size(); i++)
{
cout << wordVec[i];
}
and it outputs as such:
laptopa small computer that fits on your lap
helmetprotective gear for your head
couchwhat I am sitting on
cigarettesmoke these for nicotine
binaryones and zeros
motorcycletwo wheeled motorized bike
ojorange juice
testthis is a test
my program works if I manually input the words and add them to my data structure but if added from the vector which is filled via text file, half of the program doesnt work. before anyone says asks for a better description of the problem, all I need to know is how to fill the vector so that it will output as a single line.
You code getline(myFile, line, '#') reads everything up to end-of-file or the next '#' into line - that includes any newlines. So, as you read text file content...
laptop#a small computer that fits on your lap#
helmet#protective gear for your head#
...which you could also think of as...
"laptop#a small computer that fits on your lap#\nhelmet#protective gear for your head#"
...line takes on successive values...
"laptop"
"a small computer that fits on your lap"
"\nhelmet"
...etc....
Note the newline in "\nhelmet".
There are many ways to avoid or correct this, such as...
while ((myFile >> std::skipws) and getline(myFile, line, '#'))
...
...or...
if (not line.empty() and line[0] == '\n')
line.erase(0, 1);
...or (as Barry suggests in comments)...
while (getline(myFile, line))
{
std::istringstream iss(line);
std::string field;
while (getline(iss, field, '#'))
...
}
while(getline(myFile, line, '#'))
Here, you told std::getline to use the '#' character instead of a newline, '\n', as a delimiter.
So, this simply means that std::getline will no longer think there's anything special about '\n'. It's just another character that std::getline() will keep reading, looking for the next #.
So, you end up reading newline characters into your individual strings, and then outputing them to std::cout, as part of the strings you've printed.

c++ ifstream Skipping Data

I'm trying to get my program to read two lines out of a six line data file (the other four are two sets of two that are meant to be read to other objects). However, I can only get it to read one -- either the first or the second depending on how I manipulate the code.
Here's what's in my data file:
Mustang Sally
123.45
George Porge
11.99
J. D. Rockerfeller
56321.3
And here's the section of the code where I need to read said data:
void account::readAccount(ifstream &inFile)
{
while (getline(inFile, name))
{
inFile.ignore();
inFile >> savings;
}
}
The code above is only reading in the second line.
I think I'm having a phantom newline problem, which I can't seem to resolve, but I also feel that there's another problem on top of that, which I can't comprehend with my current level of experience regarding file streams.
The code above is only reading in the second line.
Yes because you tell it to ignore. I don't know what exactly two lines you want to get from these, but based on the codes, I'm assuming that you want to read the values at line 2,4. The following code will print out those two lines.
float savings = 0.0f;
while(getline(inFile,line))
{
if(savings > 0.0f) cout << savings << endl;
inFile >> savings;
inFile.ignore(1000, '\n' );
}

How to extract specific substring from getline function in C++?

I'm fairly new to C++ so please forgive me if my terminology or methodology isn't correct.
I'm trying to write a simple program that:
Opens two input files ("infileicd" and "infilesel").
Opens a single output file "list.txt".
Compares "infilesel" to "infileicd" line by line.
If a line from "infilesel" is found in "infileicd", it writes that line from "infileicd" to "list.txt", effectively making a separate log file.
I am using the getline() function to do this but have run into trouble when trying to compare each file line. I think it might be easier if I could use only the substring of interest to use as a comparison.
The problem is that there are multiple words within the entire getline string and I am only really interested in the second one. Here are two examples:
"1529 nic1_mau_op_mode_3 "8664afm007-01" "1" OUTPUT 1 0 LOGICAL 4 4136"
"1523 pilot_mfd_only_sel "8664afm003-02" "1" OUTPUT 1 0 LOGICAL 4 4112"
"nic1_mau_op_mode_3" and "pilot_mfd_only_sel" are the only substrings of interest.
It would make it a lot easier if I could only use that second substring to compare but I don't know how to extract it specifically from the getline() function. I haven't found anything suggesting it is impossible to do this, but if it is impossible, what would be an alternative method for extracting that substring?
This is a personal project so I'm under no time contstraints.
Any assistance is greatly apprecated in advance. Here is my code (so far):
int main()
{
//Open the file to write the selected variables to.
ofstream writer("list.txt");
//Open the selected variabels file to be read.
ifstream infilesel;
infilesel.open("varsel.txt");
//Open the icd file to be read.
ifstream infileicd;
infileicd.open("aic_fdk_host.txt");
//Check icd file for errors.
if (infileicd.fail()){
cerr << "Error opening icd.\n" << endl;
return 1;
}
else {
cout << "The icd file has been opened.\n";
}
//Check selected variables file for errors.
if (infilesel.fail()){
cerr << "Error opening selection file.\n" << endl;
return 1;
}
else {
cout << "The selection file has been opened.\n";
}
//Read each infile and copy contents of icd file to the list file.
string namesel;
string nameicd;
while(!infileicd.eof()){
getline(infileicd, nameicd);
getline(infilesel, namesel);
if (nameicd != namesel){ //This is where I would like to extract and compare the two specific strings
infileicd; //Skip to next line if not the same
} else {
writer << nameicd << namesel << endl;
}
}
writer.close();
infilesel.close();
infileicd.close();
return 0;
}
So, based on what we discussed in the comments, you just need to toss the stuff you don't want. So try this:
string namesel;
string nameicd;
string junk;
while(!infileicd.eof()){
// Get the first section, which we'll ignore
getline(infileicd, junk, ' ');
getline(infilesel, junk, ' ');
// Get the real data
getline(infileicd, nameicd, ' ');
getline(infilesel, namesel, ' ');
// Get the rest of the line, which we'll ignore
getline(infileicd, junk);
getline(infilesel, junk);
Basically, getline takes a delimiter, which by default is a newline. By setting it as a space the first time, you get rid of the first junk section, using the same method, you get the part you want, and then the final portion goes to the end of the line, also ignoring it.

How to construct a parser for an input file

can i please get some guidance to constructing a parser for an input file, I've been looking for a help for weeks, the assignment is already past due, I would just like to know how to do it.
The commented code is what I've tried, but i have a feeling it is more serious than that. I have a text file and I want to parse it to count the number of times that words appear in the document.
Parser::Parser(string filename) {
//ifstream.open(filename);
// source (filename, fstream::in | fstream::out);
}
The commented code is what I've tried, but i have a feeling it is more serious than that.
I have a feeling you haven't tried a thing. So I am going to do the same.
Google is your friend.
To read a word:
std::ifstream file("FileName");
std::string word;
file >> word; // reads one word from a file.
// Testing a word:
if (word == "Floccinaucinihilipilification")
{
++count;
}
// Count multiple words
std::map<std::string, int> count;
// read a word
++count[word];
// To read many words from a file:
std::string word;
while(file >> word)
{
// You have now read a word from a file
}
Note: That is a real word :-)
http://dictionary.reference.com/browse/floccinaucinihilipilification
Take a look at the answers in How do you read a word in from a file in C++? . The easiest way is to use an ifstream and operator>> to read single words. You can then use a standard container like vector (as mentioned in the link above) or map<string, int> to remember the actual count.