std::stringstream output does not work the same as std::string

Question

i am currently working on a program whereby i can substitute alphabets in a text file(called plaintext.txt), along with a keyfile, and create a ciphertext when i run a command to mix them together. The working code is as shown below:

string text;
string cipherAlphabet;

string text = "hello";
string cipherAlphabet = "yhkqgvxfoluapwmtzecjdbsnri";

string cipherText;
string plainText;

bool encipherResult = Encipher(text, cipherAlphabet, cipherText);
bool decipherResult = Decipher(cipherText, cipherAlphabet, plainText);  

cout << cipherText;
cout << plainText;

Output for the above code will be below

fgaam
hello

However, i want to convert my "text" and "cipherAlphabet" into a string where i obtain the both of them through different text files.

string text;
string cipherAlphabet;


std::ifstream u("plaintext.txt"); //getting content from plainfile.txt, string is text
std::stringstream plaintext;
plaintext << u.rdbuf();
text = plaintext.str(); //to get text


std::ifstream t("keyfile.txt"); //getting content from keyfile.txt, string is cipherAlphabet
std::stringstream buffer;
buffer << t.rdbuf();
cipherAlphabet = buffer.str(); //get cipherAlphabet;*/

string cipherText;
string plainText;

bool encipherResult = Encipher(text, cipherAlphabet, cipherText);
bool decipherResult = Decipher(cipherText, cipherAlphabet, plainText);  

cout << cipherText;
cout << plainText;

However if i do this, i get no output and no error? Is there anyone out there that can help me with this please? Thank you!!

Always check `if (t)` before reading from it to see if the state is still good. — Hatted Rooster, Oct 18 '17 at 16:24
You are not reading the file. Just read the file into a std::string and be done with it. You can google how. — Anon Mail, Oct 18 '17 at 16:24
@AnonMail OP is actually reading the file by using `rdbuf()`. — Hatted Rooster, Oct 18 '17 at 16:25
@RickAstley my bad. But why read it into a std::stringstream? — Anon Mail, Oct 18 '17 at 16:26
`rdbuf()` will give you a pointer to `filebuf`. Please read on [how to read from `rdbuf()`](http://www.cplusplus.com/reference/fstream/ifstream/rdbuf/). — Griffin, Oct 18 '17 at 16:27
See this link on how to read an entire file into a std::string. Check out the 8th answer in this post: https://stackoverflow.com/questions/116038/what-is-the-best-way-to-read-an-entire-file-into-a-stdstring-in-c — Anon Mail, Oct 18 '17 at 16:31

R Sahu · Accepted Answer · 2017-10-18T16:49:04.640

1

std::ifstream u("plaintext.txt"); //getting content from plainfile.txt, string is text
std::stringstream plaintext;
plaintext << u.rdbuf();
text = plaintext.str(); //to get text

When you use the above lines of code to extract text, you are getting any whitespace characters in the file too -- most likely a newline character. Simplify that block of code to:

std::ifstream u("plaintext.txt");
u >> text;

Same change needs to be done to read the cipher.

If you need to include the whitespaces but exclude the newline character, use std::getline.

std::ifstream u("plaintext.txt");
std::getline(u, text);

If you need to be able to deal with multiline text, you will need to change your program a bit.

edited Oct 18 '17 at 16:49

answered Oct 18 '17 at 16:27

R Sahu

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Thank you for the fast reply! However, i would like to make use of the function's ability to read spaces in between strings too. for now, im just try to read with one line of string in the text file. i had some difficulty with reading spaces in text file using while and for loops before, and i came across this reading of text file without using loops. – fabian Oct 18 '17 at 16:44
@fabian, in that case, you need to use `std::getline`. `std::getline(u, text);`. That will include any spaces but will exclude the ending newline character. – R Sahu Oct 18 '17 at 16:47

std::stringstream output does not work the same as std::string

1 Answers1