lib.sys.listdir Re: C Function returning a table to LUA?

[Asko Kauppi <asko.kauppi@...>]

Both LuaCheia and GluaX provide the kind of service you mention, and it 
works for Linux, Win32 and OS X. From gluax 'sys_module.c' (returns a 
table using gluax macros):

    //---
    // [tbl]= listdir( [path_str [,mask_str]] )
    //
    // Returns: { "file1.ext", "file2.ext", "dir1/", ... }
    //          { }     (if no files matching the 'mask')
    //          nil     (if no such directory)
    //
    // Note:    Tree recursion etc. are done in a Lua wrapper.
    //
    GLUA_FUNC( listdir )
    {
    const char* path= glua_getString(1);
    const char* mask= glua_getString(2);
    DIR* dir;
    struct dirent* entry;
    uint n=0;

        if (!path || !path[0])
            path= ".";  // default (current dir)

        dir= opendir( path );
        //
        // NULL on failure, 'errno' gives more info:
        //
        //      ENOENT:     No such directory
        //      EINVAL:     Invalid argument or directory name
        //      ENOMEM:     Not enough memory to perform the operation

        if (!dir) break;    // jumps to 'GLUA_END', returns nil.

        glua_pushTable();
            {
            char buf[ PATH_MAX ];

            while( (entry= readdir(dir)) != NULL )
                {
                const char* name= entry->d_name;

                if ( (strcmp(name,".")==0) || (strcmp(name,"..")==0) )
                    continue;   // skip "." and ".." always

                if (mask && !Loc_MaskMatch(name,mask))
                    continue;   // masked out

                if (Loc_IsDir(path,name))
                    {
                    name= strcpy_safe( buf, name, sizeof(buf) );
                    strcat_safe( buf, "/", sizeof(buf) );
                    }

                glua_setTable_str_i( ++n, name );
                }
            }

        closedir( dir );
    }
    GLUA_END



Andy Bushnell kirjoittaa maanantaina, 29. syyskuuta 2003, kello 10:18:

> Hi,
>
> Please excuse my ignorance (i'm a Lua newbie).
>
> I have a 'C' function (getFileListing) that has been registered with 
> Lua. It
> compiles a list of files in the current working directory. Everything 
> works
> fine until I try *returning* this info to Lua. How can I do it?
>
> My Lua script (right now) makes the call...
>
> getFileListing()
>
> Nothing happens but printf's in the getFileListing function show that 
> its
> being called & doing the right thing. So now I have an array of 
> strings (the
> file names) in the 'C' side but I want to pass this info back to the 
> script.
> I think I need to use a "Table" to pass this info to Lua, but tables 
> are new
> to me and I cant see an example which does what I want (which, as a 
> newbie,
> im looking for!).
>
> I'd like my script (I think) to look something like ...
>
> t = getFileListing() -- where t is the returned table
>
> -- check for table size
>
> -- iterate through table getting the file listing names
>
> (im not sure of the exact table iteration syntax - but I can work that 
> out
> later).
>
> I hope this isnt too simple a question - but any help would greatly
> appreciated.
>
> Regards,
>
> Andy