Re: [PATCH 2/3] ios: Move file name normalization logic into ios-dev.h

[Jose E. Marchesi]

    On 7/12/20 11:32 AM, Jose E. Marchesi wrote:
    > Hi Ege.
    >
    >      +#define IOS_FILE_HANDLER_NORMALIZE(handler, newhandler)             
        \
    >      +{                                                                   
\
    >      +  /* File devices are special, in the sense that they accept any    
\
    >      +     handler. However, we want to ensure that the ios name is       
        \
    >      +     unambiguous from other ios devices, by prepending ./ to 
relative       \
    >      +     names that might otherwise be confusing.  */                   
\
    >      +  static const char safe[] =                                        
        \
    >      +    "abcdefghijklmnopqrstuvwxyz"                                    
\
    >      +    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"                                    
\
    >      +    "0123456789/+_-";                                               
        \
    >      +                                                                    
\
    >      +  if (handler[0] == '/' || strspn (handler, safe) == strlen 
(handler))      \
    >      +    (newhandler) = strdup ((handler));                              
        \
    >      +                                                                    
\
    >      +  if (asprintf (&(newhandler), "./%s", (handler)) == -1)            
\
    >      +    (newhandler) = NULL;                                            
\
    >      +}
    >
    > Maybe it would be better to use a static inline function here?
    > Otherwise, please surround the macro body with do..while(0)
    >
    > Other than that, OK for master.
    > Thanks! :)
    
    I am not happy with the implicit declaration warnings due to asprintf,
    with including stdio.h here or adding pragmas.
    I am keeping it as the macro for now. In nearby-future, if
    ios-dev-stream and ios-dev-file end up sharing more code, we can 
    consider getting those two a new .h file exclusively.
    
    I added the do-while upon your request and pushed the changes.

Ok, thanks :)

I played with the stream IOS implementation using the following little
Poke implementation of `strings' (yeah, it is the first Poke filter ever
written, and as you can see it uses the strategy we foresaw at Mont
Soleil):

-----<-------
#!/usr/local/bin/poke -L
!#

/* Printable ASCII characters: 0x20..0x7e */

defvar stdin = open ("<stdin>");
defvar stdout = open ("<stdout>");

defvar offset = 0#B;

try
{
  flush (stdin, offset);

  defvar b = byte @ stdin : offset;
  if (b >= 0x20 && b <= 0x7e)
    byte @ stdout : iosize (stdout) = b;

  offset = offset + 1#B;
}
until E_eof;

close (stdin);
close (stdout);
------>-------

It works, up to some point:

$ cat /usr/bin/ncal | ./pstrings
poke: ../../libpoke/ios-buffer.h:244: ios_buffer_forget_till: Assertion 
`buffer->end_offset >= buffer->begin_offset' failed.
ELF> @m@8@@@@888WW ]] Aborted (core dumped)

This is very exciting :)