#fopen() cannot read files from different directories

49 messages · Page 1 of 1 (latest)

glossy bough
#

Hello, quick question.

Why wouldn't the file open? The directory I am accessing is correct when I tried ls /path/to/*.bin , but it does not recognise the path as it seems.

uint8_t ram[0x10000];

int 
load_file(m65xx_core_t* const m, const char* file_to_load, uint16_t addr)
{
printf("Trying to open file: '%s'\n", file_to_load);
  FILE *f = fopen(file_to_load, "rb");

  if(f == NULL) 
  {
    fprintf(stderr, "**" RED " Error " RESET "** " "file couldn't be opened");
    return 1;
  }

  fseek(f, 0, SEEK_END);
  size_t file_size = ftell(f);
  rewind(f);

  if(file_size + addr > 0x10000) 
  {
    fprintf(stderr, "\n**" RED "Error" RESET "** " "file size to large\n"); 
    fclose(f); 
    return 1;
  }

  size_t file_read = fread(&ram[addr], sizeof(uint8_t), file_size, f);

  if(file_read != file_size) 
  {
    fprintf(stderr, "**" RED " Error " RESET "** " "file \"%s\" couldn't be read into memory" , file_to_load); 
    fclose(f); 
    return 1;
  }

  fclose(f);
  return 0;
}

static int execute_allsuiteasm(m65xx_core_t* const m, const char* file_to_load) {
    memset(ram, 0, 0x10000);

    // Check if the file was loaded successfully
    if (load_file(m, file_to_load, 0x4000) != 0) {
        fprintf(stderr, "**" RED " Error " RESET "** failed to load file. Aborting execution.\n");
        return 1;  // Exit if file loading fails.
    }

    m65xx_power(m);

    printf("\n** file loaded: " BOLD "%s" RESET " **\n", file_to_load);

    while (1) {
        m65xx_run(m);
        if (m->pc == 0x45C0) {
            if (rb(m, 0x0210) == 0xFF) {
                printf(GREEN "✓" RESET " - test passed!\n");
            } else {
                printf(RED "✘" RESET " - test failed!\n");
            }
            break;
        }
    }

    return 0;
}

main(): execute_allsuiteasm(&m, "../tests/AllSuiteA.bin");
sacred socketBOT
#

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glossy bough
#

The error message:

 ________    ________    ______       ________
|\   ____\  |\   ____\  /___   \     |\   __  \
\ \  \      \ \ \ ___/  \___ \  \    \ \  \|\  \
 \ \  \_____ \ \ \_____     \ \  \    \ \  \|\  \
  \ \    _  \ \ \_______\    \ \  \    \ \  \|\  \
   \ \  \|\  \ \/______\ \    \ \  \    \ \  \|\  \
    \ \_______\ ________\ \  __\_\  \___ \ \_______\
     \|_______| \_\________\ \_\________\ \|_______|
Trying to open file: '../tests/AllSuiteA.bin'
** Error ** file couldn't be opened** Error ** failed to load file. Aborting execution.
❯ ls -l ../tests/AllSuiteA.bin
.rw-r--r--@ 49k cupko 13 Jul 14:42 ../tests/AllSuiteA.bin
~/Documents/dev/c/emulation/m65xx/src main* ❯
# 
❯ ls -l
drwxr-xr-x@   - cupko  6 Nov 18:15 include
.rw-r--r--@ 670 cupko  6 Nov 18:30 Makefile
drwxr-xr-x@   - cupko  6 Nov 18:49 src
drwxr-xr-x@   - cupko  5 Nov 23:10 tests
~/Documents/dev/c/emulation/m65xx main* ❯
mossy hull
#

permission issues maybe?

#

also what is the working dir

#

where is the binary executed from

glossy bough
#

The directories are both readable and writeable

mossy hull
#

so if the binary is in m65xx, you should open tests/AllSuiteA.bin

sharp narwhal
#

also using perror is good, as it would tell you the problem ;p

#

like "file not found"

glossy bough
mossy hull
#

thats not how it works

sharp narwhal
#

it matters where the binary is executed

glossy bough
mossy hull
#

yes

sharp narwhal
#

the path is interpreted during runtime

#

it doesn't even matter where the binary is

glossy bough
#

I did not know that

sharp narwhal
#

it matters what is your working directory

#

as you can give full path to your binary and run it from somewhere else

#

and then it will still fail

#

because the path will be relative to cwd

#

it will work if you run it from src though :P

sharp narwhal
glossy bough
#

But

sharp narwhal
#

perror prints your messages and message for errno

#

to stderr

glossy bough
#

My executable file is in the root directory though and I did ../tests/AllSuiteASM for the file path

#

Shouldn’t it still work tho

#

Since I change the directory to .. first

sharp narwhal
#

I wonder what do you mean by "root directory"

#

root directory would me normally literally /

#

which wouldn't be a usual place to store your files

mossy hull
#

prob refers to workspace dir

glossy bough
# 
❯ make
[compiling] src/debugger.c
[compiling] src/m65xx.c
[compiling] src/main.c
src/main.c: In function ‘load_file’:
src/main.c:21:31: warning: unused parameter ‘m’ [-Wunused-parameter]
   21 | load_file(m65xx_core_t* const m, const char* file_to_load, uint16_t addr)
      |           ~~~~~~~~~~~~~~~~~~~~^
[linking] src/debugger.o src/m65xx.o src/main.o
[produced] m65xx
❯ ls
include  m65xx  Makefile  src  tests
❯ ls -l
drwxr-xr-x@   - cupko  6 Nov 18:15 include
.rwxr-xr-x@ 78k cupko  6 Nov 19:04 m65xx
.rw-r--r--@ 670 cupko  6 Nov 18:30 Makefile
drwxr-xr-x@   - cupko  6 Nov 19:04 src
drwxr-xr-x@   - cupko  5 Nov 23:10 tests
~/Documents/dev/c/emulation/m65xx main* ❯

m65xx is the executable

sharp narwhal
#

so .. goes to ~/Documents/dev/c

glossy bough
sharp narwhal
#

and then looks for tests there

#

again, .. are relative to a directory you are in when launching the executable, you, not the executable per se

#

that convention is convenient for your user passing you a path, e.g. imagine you were writing program showme that would display a file, you have showme in c:\myprogs\showme, you are in a directory c:\foo\bar and you want to display file c:\foo\file.txt

#

then being in c:\foo\bar you would run c:\myprogs\showme ../file.txt (or if c:\myprogs was in PATH, then it would be just showme)

glossy bough
#

oh

#

I understand now

#

thank you

sacred socketBOT
#

@glossy bough Has your question been resolved? If so, type !solved :)

glossy bough
#

!solved