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SubjectRe: scripts/makelst: bc -> shell Re: sed _s_gnu_alternatives_ (Re: [rft] (g)awk substitution)
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On Sat, Feb 03, 2007 at 12:24:59PM +0100, David Weinehall wrote:
> On Sat, Jan 27, 2007 at 06:38:36AM +0000, Oleg Verych wrote:
> [snip]
> > ,-*- diff snip -*-
> > |- t4=`echo $t3 | gawk '{ print $1 }'`
> > |- t5=`echo $t1 | gawk '{ print $1 }'`
> > |+ t4=`pos_param 1 $t3`
> > |+ t5=`pos_param 1 $t1`
> > 5 t6=`echo $t4 - $t5 | tr a-f A-F`
> > 6 t7=`( echo ibase=16 ; echo $t6 ) | bc`
> > `-*-
> >
> > I've just noticed, that things on lines 5 and 6 may be optimized.
> >
> > t7=`printf "%lu" $(( 0x$t4 - 0x$t5 ))`
>
> %lu does not seem to agree with SuSv3:
>
> http://www.opengroup.org/onlinepubs/009695399/utilities/printf.html
> http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap05.html

,-*- xbd_chap05.html -*-
| The EXTENDED DESCRIPTION section almost exactly matches the
| printf() function in the ISO C standard, although it is described
| in terms of the file format notation in the Base Definitions volume
| of IEEE Std 1003.1-2001, Chapter 5, File Format Notation.
`-*-
In other words, it does *not* match it at all. How it can without
the length modifiers?

As for me, "shalls" and "shoulds", "Implementations are encouraged" are
standard terms of The Standards.

Thus, i think, "%ul" is more "implementation wise":

,-*- printf test on bash, dash, busybox -*-
|olecom@flower:~$
|olecom@flower:~$ printf "%u \n" 0xffffffffffffffff
|18446744073709551615
|olecom@flower:~$ printf "%u \n" 0xffffffffffffffffA
|bash: printf: warning: 0xffffffffffffffffA: Numerical result out of range
|18446744073709551615
|olecom@flower:~$
|olecom@flower:~$ echo $BASH_VERSION
|3.1.17(1)-release
|olecom@flower:~$
|olecom@flower:~$ /bin/dash
|flower:-$ printf "%u \n" 0xffffffffffffffff
|18446744073709551615
|flower:-$ printf "%u \n" 0xffffffffffffffffA
|printf: 2: 0xffffffffffffffffA: Numerical result out of range
|18446744073709551615
|flower:-$
|flower:-$ /bin/busybox sh
|
|
|BusyBox v1.1.3 (Debian 1:1.1.3-4) Built-in shell (ash)
|Enter 'help' for a list of built-in commands.
|
|flower:-$
|flower:-$
|flower:-$ printf "%u \n" 0xffffffffffffffff
|4294967295
|flower:-$ printf "%u \n" 0xffffffffffffffffA
|0xffffffffffffffffA4294967295
|flower:-$ printf "%lu \n" 0xffffffffffffffff
|18446744073709551615
|flower:-$ printf "%lu \n" 0xffffffffffffffffA
|0xffffffffffffffffA18446744073709551615
|flower:-$
|flower:-$
`-*-

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