From: ts <decoux@...>
Date: 2002-01-31T01:25:40+09:00
Subject: Re: popen3 and buffering

>>>>> "P" == Paul Brannan <paul@atdesk.com> writes:

P> Curious as to how to get around the problem, I started to dig into io.c.
P> Both read() and sysread() call READ_DATA_PENDING, which is a macro that
P> expands to ReadDataPending.  But where is ReadDataPending defined?

 It depend of your system

#ifdef _STDIO_USES_IOSTREAM  /* GNU libc */
#  ifdef _IO_fpos_t
#    define READ_DATA_PENDING(fp) ((fp)->_IO_read_ptr != (fp)->_IO_read_end)
#  else
#    define READ_DATA_PENDING(fp) ((fp)->_gptr < (fp)->_egptr)
#  endif
#elif defined(FILE_COUNT)
#  define READ_DATA_PENDING(fp) ((fp)->FILE_COUNT > 0)
#elif defined(__BEOS__)
#  define READ_DATA_PENDING(fp) (fp->_state._eof == 0)
#else
/* requires systems own version of the ReadDataPending() */
extern int ReadDataPending();
#  define READ_DATA_PENDING(fp) ReadDataPending(fp)
#endif


Guy Decoux