C++ Trying to use fscanf to read a text file and store into struct | Together C & C++ | Page 1

old jayBOT Sep 15, 2022, 6:59 PM

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crude wyvern Sep 15, 2022, 7:02 PM

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C++ Trying to use fscanf to read a text file and store into struct

spare bridge Sep 15, 2022, 7:19 PM

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is this C or C++?

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do you know that std::ifstream exists in C++?

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wait a minute, this is your first week in C++, and you are writing this?

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yep, here you are writing in C, this has nothing in common with C++, so where is the problem?

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which words are not read correctly?

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in other words you do not correctly detect the empty line used as a separator?

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fscanf is meant to read non-whitespace characters, it completely skips over \n

vapid crane Sep 15, 2022, 7:41 PM

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you probably want to consider using getline to read the file first, then parse the contents later

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https://wandbox.org/permlink/3da1aA3j1ZdYbjpH

[C++] gcc 12.1.0 - Wandbox

#include
#include
#include
#include

using namespace std;

ve

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this would be the "C++ way" to do this

spare bridge Sep 15, 2022, 7:41 PM

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vapid crane https://wandbox.org/permlink/3da1aA3j1ZdYbjpH

he hasn't used the STL ever, he knows C only

vapid crane Sep 15, 2022, 7:41 PM

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or you could try to parse inline on demand, during read

vapid crane Sep 15, 2022, 7:42 PM

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spare bridge he hasn't used the STL ever, he knows C only

I'm able to read and follow the conversation, I'm not unaware of the situation

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I gave an example, is that a problem for you?

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really it doesn't matter if it's a problem for you, it matters if it helps meowstars

spare bridge Sep 15, 2022, 7:48 PM

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have you used malloc?

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if you have, create a cusom global function called readLine, by using the function fread and reading 1 byte at a time, from there extract the individual words with sscanf

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when an empty line is detected, you will know that this is the separator

vapid crane Sep 15, 2022, 7:52 PM

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why do things the old shit C way if this is a C++ course

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unless the professor mandates it

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which is quite plausible, but it doesn't seem this has been yet stipulated as a requirement

spare bridge Sep 15, 2022, 7:57 PM

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yes, fgetc is the same as calling fread with 1 byte as the 3rd parameter

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also, you might need ungetc to teleport back to th previous character
https://pubs.opengroup.org/onlinepubs/007908799/xsh/ungetc.html

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since in C you can't read 1 character without advancing the file pointer one character forward

vapid crane Sep 15, 2022, 7:59 PM

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or we could encourage using C++ which also has a function to get a single character at a time from a stream

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https://en.cppreference.com/w/cpp/io/basic_istream/get

cpp/io/basic istream/get

spare bridge Sep 15, 2022, 7:59 PM

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vapid crane https://en.cppreference.com/w/cpp/io/basic_istream/get

I was talking about peek()

old jayBOT Sep 16, 2022, 6:57 PM

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Thank you and let us know if you have any more questions!

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[SOLVED] C++ Trying to use fscanf to read a text file and store into struct

#C++ Trying to use fscanf to read a text file and store into struct