Question about paths and the length of the char arrays for paths

[TenguBoss]

Aloha 42 Team.

I just installed 42 on WSL2 and I verified that it works correctly with the demos provided. It has improved a lot since I tried it about 10(?) years ago. Thank you!

When I tried to run it on a Windows directory I got an error that made me "reverse engineer" the following command line

$ ./42 ../../../mnt/c/very/very/very/very/very/very/very/very/long/path/here/Missions/Agena-D_ADR/42sim/InOut

The command failed with

Error opening ssions/Agena-D_ADR/42sim/InOut/42.mtl

I copied 42.mtl to the directory, reran, and got the same error. I assumed that this had to do with path definitions so I edited 42.h to increase the length of the path char arrays.

I changed

EXTERN char InOutPath[80];
EXTERN char ModelPath[80];
EXTERN char CmdFileName[80];

to

EXTERN char InOutPath[512];
EXTERN char ModelPath[512];
EXTERN char CmdFileName[512];

remade 42, ran the command line, and confirmed that it worked.

Now I have two questions:

1. Is my assumption about the string for the path, as seen in the command above, correct? (I haven't been able to find the function that assigns ModelPath and it seems that 42 assumes some form of relative path to generate ModelPath.)
2. Is there a chance that I will run into problems because the path char arrays are now six times longer? If yes, should I find another workaround?

Before you suggest it, I am required to store the working (InOut) files in the Windows file system in specific directories.

Thank you.

BU

[ericstoneking]

1. Yes. FWIW, ModelPath is set in 42init.c:InitSim. The default is "./Model/", but you can replace that with the second argument in your command-line invocation of 42, as in "42 MyInOut MyModels".

2. Not that I'm aware of. But then, I didn't have the imagination to encompass somebody needing a 512-character path in the first place :-). There are several places where ModelPath is passed as an argument to a function. I think that all of those have been made to accept "const char *Path" instead of the old "char Path[80]" style. If you find any instances of the old way, let me know and I'll fix them.

[TenguBoss]

Thank you Eric for the prompt reply. This was an edge case due to WSL2 + Windows requirements.

I looked for char Path[80] with

$ find ~/42/ -name "*.c" -exec grep -Hi "char [Pp]ath\[80\]" {} \;

and found it here:

/home/homedir/42/Kit/Source/geomkit.c:void WriteGeomToObjFile(struct MatlType *Matl,struct GeomType *Geom,const char Path[80]
/home/homedir/42/Kit/Source/glkit.c:GLuint PpmToRingTexTag(const char path[80], const char filename[80])

As I was looking at the source code, I also noticed that path[40] came up in several places in source code in the World and Kit directories.

As I mentioned in the previous email, I didn't get an error yet, but I worked on the simplest of the demos. I'll post an update if I encounter problems.

...

I have changed the assignments to InOutPath and ModelPath from

if (argc > 1) sprintf(InOutPath,"./%s/",argv[1]);
if (argc > 2) sprintf(ModelPath,"./%s/",argv[2])

to

if (argc > 1) sprintf(InOutPath,"%s/",argv[1]);
if (argc > 2) sprintf(ModelPath,"%s/",argv[2]);

With this change I can call 42 with the absolute path of the InOut and Model directories, like so:

$ ./42 /mnt/c/BU/01_Research/01_VisSidus/04_BROHANa-R/Systems_engineering/Design_Reference_Missions/Agena-D_ADR/42sim/test1

So far, so good!

Best regards,

BU

-edit- included change of InOutPath and ModelPath