forwarded 329025 upstream quit Hi Herbert, please see http://bugs.debian.org/329025 and comments below. I personally think there's one example dash should support.
On Sat, Nov 05, 2005 at 09:52:17PM +0100, David Weinehall wrote: > On Sun, Sep 25, 2005 at 07:56:47PM +0000, Gerrit Pape wrote: > > On Mon, Sep 19, 2005 at 12:06:46AM +0200, David Weinehall wrote: > > > Please consider implementing full SuSv3 support for arithmetic expansion. > > > > > > http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_04 > > > > > > ``If the shell variable x contains a value that forms a valid integer > > > constant, then the arithmetic expansions "$((x))" and "$(($x))" shall > > > return the same value.'' > > > > hmm, can you give an example where this actually is used? > > I use $(()) constructs very frequently to do shell script arithmetics. > I usually use the form $((x+<val>)), but I've seen others use the > $(($x+<val>)) form too. I'm still not sure about this, how to interpret the specification. It only talks about $((x)), not $((x+something)). > > > Also: > > > > > > ``All changes to variables in an arithmetic expression shall be in effect > > > after the arithmetic expansion, as in the parameter expansion > > > "${x=value}".'' > [EMAIL PROTECTED]:~# dash -c 'unset x; echo $(($x=14)); echo $x' > dash: arith: syntax error: "=14" This sould be $ dash -c 'unset x; echo $((x=14)); echo $x' Ok, this one should work, http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_04 specifies the rules arithmetic expansion should follow, including '='. $ pdksh -c 'unset x; echo $((x=14+7)) $x' 21 21 $ posh -c 'unset x; echo $((x=14+7)) $x' 21 21 $ dash -c 'unset x; echo $((x=14+7)) $x' dash: arith: syntax error: "x=14+7" $ > [EMAIL PROTECTED]:~# dash -c 'unset x; unset y; echo $((${x=3},${y=4})); echo > $x $y' > dash: arith: syntax error: "3,4" This construct I don't know, a ',' operator isn't mentioned in the standards, so I don't think dash should be changes for this. > [EMAIL PROTECTED]:~# posh -c 'unset x; unset y; echo $((${x=3},${y=4})); echo > $x > $y' > 4 > 3 4 Hmm, strange that posh does this. Thanks, Gerrit. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
