Questions tagged [recover]

recover.c, one of the assignments for Problem Set 4, will challenge you to search through the raw bytes of a camera's digital memory to recover a bunch of "deleted" JPEG images.

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Struggling with recover.c

Its getting compiled hence syntactically correct. But after execution it had just made 1 new jpg file and too corrupted. Could you please help me out here. I have used 508 instead of 512 ...
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recover not working pset4 cs50. Doesn't show images properly

I've been checking lots of answers to people with a similar problem. But I don't get this to work yet. My code recovers all the images, but the last image is empty. I've read answers and check the ...
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Pset4 recover help

int counter = 0; FILE* inptr = fopen("card.raw", "r"); BYTE compare[512]; fread(&compare, 512, 1, inptr); while (!feof(inptr)) { if ((compare[0] == 0xff) && (compare[1] == 0xd8) &&...
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PSET4, RECOVER: Segmentation Fault

I have been trying to solve RECOVER from PSET4 and I keep getting a segmentation fault. Any ideas on why this happens? #include <stdio.h> #include <stdlib.h> #include <stdint.h> ...
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(Recover) Segmentation fault

I was trying to complete the recover problem and it's giving me a segmentation fault. Any help would be appreciated. #include <stdio.h> #include <stdlib.h> #include <stdbool.h> #...
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Pset4 Recover - only one corrupted picture is recovered!

I'm not sure what I'm doing wrong. I tried to follow the walkthrough. My code is below. Any help will be appreciated. typedef uint8_t BYTE; typedef struct { BYTE first; BYTE second; ...
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Pset4 recover.c I'm able to recover all images. But Check50 is not passing

:) recover.c exists :) recover.c compiles :) handles lack of forensic image :) recovers 000.jpg correctly :( recovers middle files correctly :( recovers last file correctly I am able to see all 50 ...
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Debug50 won't even open and I don't know what step to take next in lab4 Recover

Because I can't get debug50 to help me out, I don't know where to start to debug this program. I think I have an infinite loop somewhere, but I'm not sure. Any help to get me started on right path ...
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CS50 Recover.c | No idea what and where i'm going wrong | Can't debug or compile in CS50 IDE

I'm trying to debug in CS50 IDE but I'm continuously receiving this error; debug50: recover: No such file. and if I try to compile it says this "make: *** No rule to make target 'recover'. Stop." ...
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Debug50 Running through breakpoints

I am trying to use debug50 for PSET 4 (Recover). However, when I set the breakpoints the debugger runs through them and do not pause. Only when I set the breakpoint at the if statement shown in the ...
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How to skip loop iterations with debug50?

I'm struggling with the recover problem. I'm running a while loop that's more than 7 thousand iterations long. I get a segmentation fault because (i'm pretty sure) of the last or perhaps the last but ...
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Pset 4 Recover - How to check for first jpeg?

I feel like I have been able to implement the majority of the pseudocode but I am struggling to think of a way to find the first jpeg. I thought my code would work but it doesn't as buffer[0]... etc ...
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PSET 4 Code fails two checks

Stuck on this problem for days and I can't figure out why my code is failing, I'll admit I'm struggling to really understand what my code is doing, like how the filename variable works. But I've ...
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PSET4 Recover, Dynamic File Names

So far I've gotten to the point where I can recover one image. I'm to the point where I need to find a good way to make dynamic variable names. I thought of one way to do it, but it seems rather ...
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CS50/PSET4/RECOVER- Error- “Can't open card.raw: file format unsupported”

Keep getting "Can't open card.raw: file format unsupported" error when running the code. Not sure what I'm doing wrong. #include <stdio.h> #include <stdlib.h> int main(int argc, char *...
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Pset4/recover: Why does it not works? Image names are correct. But it doesn't match. Please help?

:) recover.c exists. :) recover.c compiles. :) handles lack of forensic image :( recovers 000.jpg correctly recovered image does not match :( recovers middle images correctly recovered image ...
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Recover function in pset4

#include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <stdbool.h> /* Open memory card Repeat until end of card: Read 512 bytes of data into buffer If ...
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Pset4 Recover JPEG images do not match

Getting closer on Pset4 Recover but still working through some issues. I am now generating jpegs (yay!) but they apparently do not match the original images. So I am getting three errors: :( recovers ...
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PSET4 Recover - Can't Read Card

Having a problem with Recover. The debugger shows that "buffer" is always 0000. Tried everything I could think of here. Any ideas? #include <stdio.h> #include <stdlib.h> #include <...
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Why does my Cs50 recover programme correctly recover all images except the first one?

I wrote the below code and it recovers 51 images: 000.jpg to 050.jpg- all images except img 000 seem to have been found correctly. I'm not sure why the code isn't working? include include include ...
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Getting an “Invalid or Unsupported Image Format” while trying to open images (Recover, Pset4)

I'm currently trying out CS50's Recover (PSET4). The program compiles and I manage to get back all the 50 jpgs. But I can't open them because the image isn't correctly returned and I get an "...
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Segmentation fault pset4 recover

I'm having a segmentation fault which I'm not being able to identify. After reading about other similar problems I thought it could be that I wasn't checking if (img == NULL) but even after adding it ...
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PSET4 Recover - Cannot identify the error in my program

I'm currently trying out CS50's Recover (PSET4). The program compiles but the only output I get when I run it is 000.jpg; That too I can't open because the image isn't correctly returned and I get an &...
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CS50/pset4/recover doesnt recover img 49

Hei All, I am running my version of recover and check50 validates every check apart from the last one This is my code. I really cant figure out what's wrong. #include <stdio.h> #include <...
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why is check50 returning error of lack of forensic image and some jpg not found

this is my code // Open the card.raw file and check for NULL FILE* card_ptr = fopen("card.raw", "r"); [admin removed rest of code] and this is my error message generated from check50 :) recover.c ...
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(PSET 4 - Recover) Why is first recovered image blank?

I am on problem set 4 recover and I have nearly completed it. I have written my code and it compiles but when I run it on the card.raw file it appears to recover all the 50 photos except the 1st one ...
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My Program is not recovering the jpegs correctly

My program is compiling properly it is even recovering the images but when I am opening the image to view, it is not opening. It is showing "Invalid or Unsupported file format". Please look ...
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1answer
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Pset4 Recover Segmentation Error. Valgrind unable to find anything

I'm sorry to bring about yet another segmentation fault but I cannot for the life in me find the error (Even valgrind is kinda malfunctioning). Here's my code- #include <stdio.h> #include <...
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1answer
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pset4 recover fread segmentation fault

guys I want to ask why am I constantly getting segfault with second fread inside of a while loop after checking jpeg header. first fread works perfectly going through first several 512bytes of card....
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1answer
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Need clarity for Problem Set4 recover

I am working on set4 recover My program is always printing "Testing EOF", hence it looks card file is empty. Here is my code in detail. #include <stdio.h> #include <stdlib.h> #...
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Issue with Recover code.While using cs50 check it fails giving the following message : timed out while waiting for program to exit

#include <stdio.h> #include <cs50.h> #include <stdint.h> #include <stdlib.h> #define BLOCK_SIZE 512 #define FILE_NAME_SIZE 8 typedef uint8_t BYTE; bool is_start_new_jpeg(BYTE ...
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PSET4 Recover - Code gets stuck at if statement

I'm working on the recover problem, but when my code gets to the if statement I made that checks for the header of a JPEG file, it gets stuck. I get no errors, it simply stops iterating through the ...
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1answer
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Segmentation Fault in CS50 Recover - pset4

I would appreciate some guidance on the below issue. I have seen the other threads with the same issue but haven't had any luck applying those fixes. I am getting the below error in my code and I can'...
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1answer
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pset4 Recovered image doesnt match

I´m trying to solve the pset4 recover challenge, but i havent been able to make the program recover the full image, only one part of it. What am i doing wrong ?? This is my code: #include <stdio.h&...
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Pset4 'Recover' - Help! How can I solve this segmentation fault?

For pset4 'Recover', I'm facing a segmentation fault but I cannot find what I did wrong in my code. If I use echo$? to find where the bug is, it returns the value 1. Can someone help me to point me in ...
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1answer
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pset4-recover: can get 50 photos but a column on the left appears on the right, problems of colors and on the first portion of the photo

I've tried some different values with fread() an with fwrite() but had no new results. On the right in some pictures appears, like a column, part of the image that should be at the left, and in some ...
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1answer
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CS50 Recover outputs random symbols instead of JPEGS

I am working on pset4 recover in CS50 and I think I am almost done it. The files that it outputs though appear as a bunch of random symbols instead of a jpeg, I'm not sure why this is occurring but ...
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Recover help - only 2 imgs are getting recovered

#include <stdio.h> #include <stdlib.h> int main(int argc, char *argv[]) { if(argc != 2) { fprintf(stderr, "Usage: ./recover <filename>\n"); return 1; } ...
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I'm working on CS50 Recover, but my images aren't showing up and I can't figure out why

#include <stdio.h> #include <stdlib.h> int main(int argc, char *argv[]) { if (argc != 2) { printf("Usage: ./recover image\n"); return 1; } ...
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PSET4 Recover Segmentation Fault Help

Edit: It has been resolved. I figured it out. Anyone who has similar problem may check my answers below. Try to skip over my code to avoid spoiling yourself. // // // // I have been stuck with ...
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Pset 4 Recover output shows Segmentation Fault

#include <stdlib.h> #include <stdint.h> //to use uint8_t as BYTE typedef uint8_t BYTE; int main(int argc, char *argv[]) { if (argc != 2) { printf("INVALID. There ...
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How can I find out the size of what i have just read with fread()?

currently my code looks like this. int finds_reading_length(FILE* the_open_file, int the_block_size) { fseek(the_open_file,-the_block_size,SEEK_CUR); BYTE* buffer[the_block_size + 1]; ...
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2answers
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CS50 Recover - fread into buffer

I am working on CS50 Recovery and I am unable to get the program to check the JPEG starting header. I used debug50 and added a couple print statements to try and find the problem. Every time I run the ...
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Recovered image does not match pset3

I can't figure out what is wrong with my code. I recovered images from 000.jpg to 050.jpg. This is my code #include <stdio.h> #include <stdlib.h> #include <stdint.h> typedef ...
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Pset 4 Recover Issue

I am 2 days into PSET 4 Recover. I can get the program to compile successfully without errors but my program is not returning any JPEGs, with no errors to point me in any direction as to what might be ...
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PSET4 Recover, don't know how to go through the blocks of data!

I am content on how to read a single 512 byte block in recover, however I'm extremely confused on how to go through the rest of the blocks of the memory card i.e can you do this using fread? I was ...
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“File size limit exceeded” in Recover - how does file writing work?

I've been quite frustrated by trying to make progress in Recover. When I run my code, I am unable to make even the first JPEG file as the program continues running until the file size is exceeded. I ...
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1answer
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pset4 - can't figure out what i'm doing wrong - recover

This is the code: #include <stdio.h> #include <stdlib.h> int main(int argc, char *argv[]) { if (argc != 2) { return 1; } FILE *file = fopen(argv[1], "r&...
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PSET4 recover! dynamically allocated array does not seem to work

Hope all is well. This is probably a stupid question but I am going to ask it anyway. I have finally finished Recover (PSET4). I initially dynamically allocated an array as follows to store my 512 ...
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pset4 recover: too many JPEGs found

guys! I was solving recover, but my program finds way too many JPEGs. I believe that this is because of the following lines: // starting bytes of jpeg are in [lower, upper] uint8_t lower[4] = {0xff, ...

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