#zsh trace trap - when reading from a file

46 messages · Page 1 of 1 (latest)

midnight field
#

Running into weird error when trying to read from a file using ifstream

boreal larkBOT
#

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midnight field
# 
#include "FileLineReader.h"
#include <fstream>
#include <iostream>

std::string FileLineReader::readLineFromFile(const std::string& fileName){
    std::ifstream fileInputStream(fileName);
    std::string line;

    
    while(getline(fileInputStream, line)){
        std::cout << line << std::endl;
    }
    
}
# 
#include "FileLineReader.h"
#include <iostream>


int main(){
  FileLineReader flr;
  std::string path = "sample.txt";
  flr.readLineFromFile(path);
}
#

Running this gives zsh: trace trap

#

Never seen this error before and when I search online I can't find anything that is relevant to reading from a file

severe walrus
#

Shouldn't this be while( fileInputStream.getline(line) )?

midnight field
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I tried getline(fileInputStream, line) I still get the same error

severe walrus
#

hmm

#

File exists, ifstream doesn't give an error?

midnight field
#

the first line of readLineFromFile doesn't give any error

#

the getline(fileInputStream, line) is where the zsh: trace trap error occurs

severe walrus
# 
std::ifstream fileInputStream(fileName);
if( fileInputStream.is_open() ) {
  ok
} else { error }
midnight field
# 
std::string FileLineReader::readLineFromFile(const std::string& fileName){
    std::ifstream fileInputStream(fileName);
    std::string line;

    if (!fileInputStream.is_open()){
        while(getline(fileInputStream, line)){
            std::cout << line << std::endl;
        }        
    } else {
        throw std::runtime_error("Could not open file");
    }

    
}
#

this also results in zsh: trace trap

severe walrus
#

Do you need to explicitely set the open mode?

#

std::ifstream fileInputStream(filename, std::ios::in)

#

And if (!fileInputStream.is_open()){ should remove the !, is_open is positive on success

#

trace trap means unhandled exception

midnight field
#

the same code runs fine on an online compiler

severe walrus
#

crazy

#

I wonder why the compiler doesn't complain because of missing return statement

midnight field
#

it gives a warning

severe walrus
#

Can you give the complete code, I try here on macOS

midnight field
#

Im running it on macOS already

#

M1 Pro

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can u check with the code I already sent?

severe walrus
#

Works fine here when the file exists

# 
#include <iostream>
#include <fstream>

class FileLineReader {
public:
  std::string readLineFromFile(const std::string& fileName){
    std::ifstream fileInputStream(fileName);
    std::string line;
    
    if (fileInputStream.is_open()){
      while(getline(fileInputStream, line)){
        std::cout << line << std::endl;
      }        
    } else {
      throw std::runtime_error("Could not open file");
    }
    
    return "";
  }
};

int main(){
  FileLineReader flr;
  std::string path = "sample.txt";
  flr.readLineFromFile(path);
}
midnight field
#

what compiler are u using?

severe walrus
#

File doesn't exist: ```
libc++abi: terminating with uncaught exception of type std::runtime_error: Could not open file
Terminated due to signal: ABORT TRAP (6)

#

macos clang

midnight field
#

my existing project I get the zsh trace trap error

#

hmm

#

omg

#

I got it

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sample.txt was never pushed to the branch

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so it actually didn't exist

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I just saved a copy of sample.txt on my local device and it works now

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🤦‍♂️

#

thank you so much for helping!

#

!solved