🚀 go-pugleaf

After we installed GNU Awk 2.10 on an Encore Multimax running UMAX
3.2, we found that commands of the form
	cat file | gawk '{print $0}'

would produce no output, instead of copying standard input to standard
output.  Redirecting standard input from a normal file worked fine,
however. 

I found that iop_alloc() in awk7.c uses fstat() to determine the input
buffer size to be used for a file descriptor. Under UMAX 3.2, fstat()
on a pipe returns 0 for both the file and block size, so the input
buffer size was being set to 0.  I modified the DEFBLKSIZE macro to
fall back to BUFSIZ if the block size was 0, and the program works
fine now.  A context diff is enclosed below. 

Mic Kaczmarczik
UT Austin Computation Center
mic@emx.utexas.edu

--------------------------CUT HERE-------------------------------------

*** awk7.c.dist	Wed Apr  5 10:57:03 1989
--- awk7.c	Thu May 25 11:13:06 1989
***************
*** 754,764 ****
  	 * stat structure. So we have to make some sort of reasonable
  	 * guess. We use stdio's BUFSIZ, since that what it was
  	 * meant for in the first place.
  	 */
  #if defined(USG) || defined(MSDOS)
  #define	DEFBLKSIZE	BUFSIZ
  #else
! #define DEFBLKSIZE	stb.st_blksize
  #endif
  
  	if (fd == -1)
--- 754,767 ----
  	 * stat structure. So we have to make some sort of reasonable
  	 * guess. We use stdio's BUFSIZ, since that what it was
  	 * meant for in the first place.
+ 	 * 
+ 	 * If stb.st_blksize is 0, make the default block size BUFSIZ.
+ 	 * This happens when you fstat() a pipe under UMAX 3.2 on an Encore.
  	 */
  #if defined(USG) || defined(MSDOS)
  #define	DEFBLKSIZE	BUFSIZ
  #else
! #define DEFBLKSIZE	(stb.st_blksize ? stb.st_blksize : BUFSIZ)
  #endif
  
  	if (fd == -1)