Re: bin/48017: awk(1) fails to treat var as integer (may be related to #47840)

[Steffen "Daode" Nurpmeso <sdaoden%gmail.com@localhost>]

The following reply was made to PR bin/48017; it has been noted by GNATS.

From: Steffen "Daode" Nurpmeso <sdaoden%gmail.com@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: bin/48017: awk(1) fails to treat var as integer (may be related
 to #47840)
Date: Wed, 10 Jul 2013 10:53:13 +0200

 David Holland <dholland-bugs%netbsd.org@localhost> wrote:
  | sprintf witih %d doesn't produce an number value; it produces a
  | string value, which you have to coerce to a number by adding zero to
  | it to get it to behave like a number.
 
 (Adding +0 was my final solution too, because GNU awk(1) didn't
 make it by the (presumably more expensive, too) sprintf("%X")
 call just as all other tested awk(1)s did.)
 
 So there is a problem with the implicit type conversion, since
 
   echo f001 f00d |\
   awk '{ a=sprintf("%d", "0x" $1); b=sprintf("%d", "0x" $2); while (a < b) { 
print a; a++; }}'
 
 works just fine?!?  I think the relevant parts from POSIX are
 
   the value of an expression shall be implicitly converted to the
   type needed for the context in which it is used.
   [.]
   A numeric value that is exactly equal to the value of an integer
   (see Concepts Derived from the ISO C Standard) shall be converted
   to a string by the equivalent of a call to the sprintf function
   (see String Functions) with the string "%d" as the fmt argument
   and the numeric value being converted as the first and only expr
   argument.
   [.]
   This volume of POSIX.1-2008 specifies no explicit conversions
   between numbers and strings. An application can force an
   expression to be treated as a number by adding zero to it, or can
   force it to be treated as a string by concatenating the null
   string ( "" ) to it.
   [.]
   A string value shall be considered a numeric string if it comes
   from one of the following:
     [.]
     1. Field variables
     [.]
     8. Variable assignment from another numeric string variable
   [...]
   and an implementation-dependent condition corresponding to either
   case (a) or (b) below is met.
     [.]
     b. After all the following conversions have been applied, the
     resulting string would lexically be recognized as a NUMBER
     token as described by the lexical conventions in Grammar :
     [.]
   Whether or not a string is a numeric string shall be relevant only
   in contexts where that term is used in this section.
 
 And because the `Table: Expressions in Decreasing Precedence in awk'
 contains the line
 
   expr < expr   Less than   Numeric   None
 
 i believe its a bug.  (That hopefully gets fixed by someone who
 yet has some experience with the awk codebase.)
 
  | David A. Holland
  | dholland%netbsd.org@localhost
 
 --steffen