I get the following output: Caught fatal signal 11 and stderr terminate called without an active exception.
Here is the code for a simple Morse code decoder that works with two files (input and output): https://pastebin.com/PrGcNtRa
#Caught fatal signal 11
undone ice
main pelicanBOT
little onyx
Error 11 is a segmentation fault, usually it should print something along those lines, but maybe not in your case.
Anyways, try using a debugger to step through your code, though I have a feeling the problem is that you’re receiving an invalid character in the input, which you then try to access in the symbol table, which in turn doesn’t exist, and you try to dereference .end()
Or alternatively, someone is sending the program a kill -s 11
undone ice
Error 11 is a segmentation fault, usually it should print something along those ...
The thing is... It runs well on my Windows machine, but on Linux I get this error
So debugging on Windows doesn't give me anything as it run fine
And Linux is remote and I can't run debugger there
little onyx
You can use gdb on Linux (if you compile with -g) - gdb is fully command line
main pelicanBOT
undone ice
You can use gdb on Linux (if you compile with `-g`) - gdb is fully command line
I can't interact much with that server computer
little onyx
In that case, you can try guarding line 76 with an .has to check if the key appears in your map
undone ice
In that case, you can try guarding line 76 with an `.has` to check if the key ap...
Changed to:
if (morse_code_table.find(symbol) != morse_code_table.end()) {
decoded += morse_code_table.at(symbol);
} else {
std::cerr << "Unknown Morse code symbol: " << symbol << std::endl;
}
and still Caught fatal signal 11
Then I tried commenting out all the logic in decode_morse(const std::string &) leaving only returning at least empty string. And still getting the error! I guess it is somehow related to files/streams?
Oh no, not really. If I only return an empty string there's no problem. But if I comment some part of it, the problem is reproducible:
std::string decode_morse(const std::string &morse)
{
std::string decoded;
std::istringstream iss(morse);
std::string token;
/* Loop through each Morse code sequence separated by '|' characters */
while (std::getline(iss, token, '|')) {
std::istringstream iss2(token);
std::string symbol;
/* Loop through each Morse code symbol separated by ' ' characters */
// while (std::getline(iss2, symbol, ' ')) {
// if (symbol.empty()) {
// decoded += '!';
// } else {
// if (morse_code_table.find(symbol) != morse_code_table.end()) {
// decoded += morse_code_table.at(symbol);
// } else {
// std::cerr << "Unknown Morse code symbol: " << symbol << std::endl;
// }
// }
// }
}
return decoded;
}
So the problem is with:
std::string decode_morse(const std::string &morse)
{
std::string decoded;
std::istringstream iss(morse);
std::string token;
while (std::getline(iss, token, '|')) {
std::istringstream iss2(token);
std::string symbol;
Any ideas?
little onyx
Try making a copy of the Morse Input, and making the stream off of that, since it’s a const reference it can be placed in read only, and string stream can be constructed via move(from non-const, per spec, but maybe there’s a bug) *or there’s a problem accessing the file/with the file itself, which leads the kernel to segfault
undone ice
What I find weird is that on my Windows computer with MSVC it compiles and works just fine.
undone ice
Try making a copy of the Morse Input, and making the stream off of that, since i...
Like this std::string decode_morse(std::string morse)?
little onyx
You can put it in a new std::string variable, that way you can also verify its contents afterwards, or remove the & from your parameter
undone ice
Like this `std::string decode_morse(std::string morse)`?
With this I removed the & and got Error 11
little onyx
What happens if you comment out your both whiles?
undone ice
What happens if you comment out your both whiles?
Caught fatal signal 11
std::string decode_morse(std::string morse)
{
std::string decoded;
std::istringstream iss(morse);
std::string token;
/* Loop through each Morse code sequence separated by '|' characters */
// while (std::getline(iss, token, '|')) {
// std::istringstream iss2(token);
// std::string symbol;
//
// /* Loop through each Morse code symbol separated by ' ' characters */
// while (std::getline(iss2, symbol, ' ')) {
// if (symbol.empty()) {
// decoded += '!';
// } else {
// if (morse_code_table.find(symbol) != morse_code_table.end()) {
// decoded += morse_code_table.at(symbol);
// } else {
// decoded += '!';
// }
// }
// }
// }
return decoded;
}
Try commenting out the istringstream, maybe your server has a buggy libcpp or links/loads different ones
undone ice
Try commenting out the istringstream, maybe your server has a buggy libcpp or li...
Commenting out the istringstream seems to solve the issue...
WTF?
little onyx
It seems your libc++ is borked, either by pure chance, or intentionally (malicious or to stop students in case of this being hw)
If it’s not academia, I would suggest cordoning the server in case it’s infected
little onyx
Also, I just realized I forgot to ask, are you compiling on the same server as running the code, maybe there’s a subtle linker issue that istringstream is at a different location than what the linker may have put in, shouldn’t, linkers are pretty robust, but in this case it’s worth a shot
undone ice
Also, I just realized I forgot to ask, are you compiling on the same server as r...
Yep, compiling on the same server as running the code
undone ice
Also, I just realized I forgot to ask, are you compiling on the same server as r...
That's what I was told:
It looks like you are opening another data stream with "std::istringstream iss(morse);". For security reasons, the server may only read the IN file, write to the OUT file and may not manipulate any other file-like objects.
charred sierra
??? a string stream doesn't open a file, though
undone ice
??? a string stream doesn't open a file, though
This is my professor's response...
undone ice
??? a string stream doesn't open a file, though
Where is this documented? He won't believe me without some source
undone ice
Would it be difficult to convert stringstream to something else?
I don't want to do this since my code works, but apparently I have to....
charred sierra
you could use a string and just string.find in a loop or something
undone ice
And now getting
what(): std::bad_alloc```
It doesn't even give me a line number
std::string
decode_morse(std::string morse)
{
std::string decoded;
size_t pos = 0;
/* Loop through each Morse code sequence separated by '|' chars */
while ((pos = morse.find('|')) != std::string::npos) {
std::string token = morse.substr(0, pos);
morse.erase(0, pos + 1);
size_t pos2 = 0;
/* Loop through each Morse code symbol separated by ' ' chars */
while ((pos2 = token.find(' ')) != std::string::npos) {
std::string symbol = token.substr(0, pos2);
token.erase(0, pos2 + 1);
if (symbol.empty()) {
decoded += '!';
} else {
if (morse_code_table.find(symbol) != morse_code_table.end()) {
decoded += morse_code_table.at(symbol);
} else {
decoded += '!';
}
}
}
}
/* Check if the last token is not empty, indicating no end pause symbol */
if (!morse.empty()) {
decoded.pop_back();
decoded += '!';
}
return decoded;
}
near field
And now getting
```terminate called after throwing an instance of 'std::bad_all...
this is thrown by new usually
Does it happen on your machine, or does it only happen on the remote server?
because this could mean that no more memory was available for allocation
little onyx
I have a feeling this isn't the standard standard library but rather a self-made one. You can try iterating directly, I'm using std::string_view to keep the copy operations to a minimum:
#include <iostream>
#include <map>
#include <string>
std::map<std::string_view, char> morse_code_table = {
{".-", 'A'}, {"-...", 'B'}, {"-.-.", 'C'}, {"-..", 'D'},
{".", 'E'}, {"..-.", 'F'}, {"--.", 'G'}, {"....", 'H'},
{"..", 'I'}, {".---", 'J'}, {"-.-", 'K'}, {".-..", 'L'},
{"--", 'M'}, {"-.", 'N'}, {"---", 'O'}, {".--.", 'P'},
{"--.-", 'Q'}, {".-.", 'R'}, {"...", 'S'}, {"-", 'T'},
{"..-", 'U'}, {"...-", 'V'}, {".--", 'W'}, {"-..-", 'X'},
{"-.--", 'Y'}, {"--..", 'Z'}, {"-----", '0'}, {".----", '1'},
{"..---", '2'}, {"...--", '3'}, {"....-", '4'}, {".....", '5'},
{"-....", '6'}, {"--...", '7'}, {"---..", '8'}, {"----.", '9'},
{".-.-.-", '.'}, {"--..--", ','}, {"..--..", '?'}, {"-....-", '-'},
{"-.--.", '('}, {"-.--.-", ')'}, {"---...", ':'}, {"-.-.-.", ';'},
{"-..-.", '/'}, {"-...-", '='}, {".-.-.", '+'}, {"..--.-", '_'},
{".----.", ' '}, {"-.-.--", '!'}, {"-.-.-.", '&'}, {".-...", '&'},
{"-..-.", '\"'}, {"..--.-", '@'}, {"|", ' '}};
char decode_symbol(const std::string_view &symbol) {
if (morse_code_table.find(symbol) != morse_code_table.end()) {
return morse_code_table.at(symbol);
} else {
return '!';
}
}
std::string decode_morse(const std::string &morse) {
int current_start = 0;
std::string decoded = "";
for (int i = 0; i <= morse.size(); i++) {
if (i == morse.size() || morse.at(i) == '|') {
decoded += decode_symbol(morse.substr(current_start, i - current_start));
current_start = i+1;
}
}
return decoded;
}
int main() {
std::string a;
std::cin >> a;
std::cout << decode_morse(a);
}
;compile | -|....|.||--|.|.-|-.|..|-.|--.||---|..-.||.-..|..|..-.|.|---...||....-|..---|!
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