Re: Doc-bug Bash manpage:
Seems like this a bug in how 'groff' is configured to display various characters. Sorry the waste of space. Linda Walsh wrote: In my bash package: rpm -qi bash Name : bash Relocations: (not relocatable) Version : 4.1 Vendor: openSUSE Release : 20.25.1 Build Date: Sun 27 Feb 2011 05:51:30 AM PST Install Date: Sun 22 May 2011 01:28:49 PM PDT Build Host: build31 ... in the 'bash' manpage, under the 'set' option, under the "-e" option, there is a paragraph that starts: "Exit immediately if a pipeline (which may consist of a single simple command), a subshell command enclosed in parentheses,..." Later on, there is text: " part of any command executed in a && or ⎪⎪ list ^^ except the command following the final && or ⎪⎪, any ^^ command in a pipeline but the last," The above statement is in error. The unicode character, U+023AA, "Bracket Extension", is not a valid bash operator. read x<<<"$(echo -n "⎪"|hexdump -e '/1 "%02.2x"')" echo $x e28eaa ubytes_to_utf8 $x U+023AA ^^ not the same as "|" (though they may display the same, one knows when one cuts & pastes, or is viewing on a screen that only supports the common ascii characters...), and 'bracket extension' ain't one of them (or I wouldn't have noticed ;-/ ). Fortunately or unfortunately, some of don't work w/terms that display such as vertical bar, but as an empty square (no character mapped). In my bash package: rpm -qi bash Name : bash Relocations: (not relocatable) Version : 4.1 Vendor: openSUSE Release : 20.25.1 Build Date: Sun 27 Feb 2011 05:51:30 AM PST Install Date: Sun 22 May 2011 01:28:49 PM PDT Build Host: build31 ... in the 'bash' manpage, under the 'set' option, under the "-e" option, there is a paragraph that starts: "Exit immediately if a pipeline (which may consist of a single simple command), a subshell command enclosed in parentheses,..." Later on, there is text: " part of any command executed in a && or ⎪⎪ list ^^ except the command following the final && or ⎪⎪, any ^^ command in a pipeline but the last," The above statement is in error. The unicode character, U+023AA, "Bracket Extension", is not a valid bash operator. read x<<<"$(echo -n "⎪"|hexdump -e '/1 "%02.2x"')" echo $x e28eaa ubytes_to_utf8 $x U+023AA ^^ not the same as "|" (though they may display the same, one knows when one cuts & pastes, or is viewing on a screen that only supports the common ascii characters...), and 'bracket extension' ain't one of them (or I wouldn't have noticed ;-/ ). Fortunately or unfortunately, some of don't work w/terms that display such as vertical bar, but as an empty square (no character mapped).
Syntax Question...
I want to have an array of 'names'.
given a name, "X", I had a prefix, _p_, so have _p_X,
I want to access / manipulate it as an array.
so given I pass in a name in a var, I have to use 'indirect' syntax:
${!name}
But that doesn't seem to play well with array syntax:
${#${!name}[*]}
bash: ${#${!name}[*]}: bad substitution
What syntax would I use for this?
Re: Syntax Question...
On Sat, Aug 13, 2011 at 23:41, Linda Walsh wrote:
> ${#${!name}[*]}
> bash: ${#${!name}[*]}: bad substitution
It's probably what you're trying to avoid, but you'll probably have to
construct and then eval the right code by hand:
$(eval "echo \${#$name[*]}")
Re: Syntax Question...
On Sat, Aug 13, 2011 at 6:41 PM, Linda Walsh wrote:
>
>
>
> I want to have an array of 'names'.
>
> given a name, "X", I had a prefix, _p_, so have _p_X,
> I want to access / manipulate it as an array.
>
> so given I pass in a name in a var, I have to use 'indirect' syntax:
>
> ${!name}
>
> But that doesn't seem to play well with array syntax:
>
> ${#${!name}[*]}
> bash: ${#${!name}[*]}: bad substitution
>
> What syntax would I use for this?
>
>
>
>
Please read BashFAQ/006: http://mywiki.wooledge.org/BashFAQ/006
--
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Re: Syntax Question...
On Sun, Aug 14, 2011 at 00:49, Dennis Williamson
wrote:
> On Sat, Aug 13, 2011 at 6:41 PM, Linda Walsh wrote:
>>
>>
>>
>> I want to have an array of 'names'.
>>
>> given a name, "X", I had a prefix, _p_, so have _p_X,
>> I want to access / manipulate it as an array.
>>
>> so given I pass in a name in a var, I have to use 'indirect' syntax:
>>
>> ${!name}
>>
>> But that doesn't seem to play well with array syntax:
>>
>> ${#${!name}[*]}
>> bash: ${#${!name}[*]}: bad substitution
>>
>> What syntax would I use for this?
>
> Please read BashFAQ/006: http://mywiki.wooledge.org/BashFAQ/006
"no force in the universe can put NUL bytes into shell strings usefully"
Ain't that the goddamn Truth!
Re: Syntax Question...
` Dennis Williamson wrote:
On Sat, Aug 13, 2011 at 6:41 PM, Linda Walsh wrote:
I have to use 'indirect' syntax: ${!name}
But that doesn't seem to play well with array syntax:
${#${!name}[*]}# bash: ${#${!name}[*]}: bad substitution
What syntax would I use for this?
Please read BashFAQ/006: http://mywiki.wooledge.org/BashFAQ/006
I looked at the pageread every section that was >basic & some basic...
nothing about using indirect variables with arrays... (let alone
assigning to them)..
Still had to use an eval for assigning...
Also his page misses a really easy way to do indirect assignment for
integer vars:
b=1
a=b
(($a=23))
echo $b
23
---
It's good to know how to do that w/string-vars in 1 line too (i.e.):
ref=line
read $ref<<<$(echo "my string")
echo $line
hi there
-- but I wouldn't have known or thought of that w/out reading that
page (which only demo's the <
Re: Syntax Question...
` Michael Witten wrote:
On Sat, Aug 13, 2011 at 23:41, Linda Walsh wrote:
${#${!name}[*]}
bash: ${#${!name}[*]}: bad substitution
It's probably what you're trying to avoid, but you'll probably have to
construct and then eval the right code by hand:
$(eval "echo \${#$name[*]}")
bingo. (sigh)
I refactored and am essentially using spaces to store the values in
a string, then when I want to check the, I throw them into an array and
manip.
e.g. (not showing all supporting code)
declare -axr _plst_t='_plist_'
declare -axl defined_PLists=()
add things to the list...
plist="$_plst_t$plist"
local -al plist_deps=( $plist )
{search for value in list, ...]
unless ((found)) ; then
plist_deps[${#plist_deps[*]}]="$subdep"
eval "$plist=( "$plist_deps[@]" )"
fi
Re: Syntax Question...
On Sun, Aug 14, 2011 at 7:51 AM, Linda Walsh wrote:
>
>
>
> ` Dennis Williamson wrote:
>>
>> On Sat, Aug 13, 2011 at 6:41 PM, Linda Walsh wrote:
>>
>>>
>>> I have to use 'indirect' syntax: ${!name}
>>> But that doesn't seem to play well with array syntax:
>>> ${#${!name}[*]} # bash: ${#${!name}[*]}: bad substitution
>>>
>>> What syntax would I use for this?
>>>
>>>
>>
>> Please read BashFAQ/006: http://mywiki.wooledge.org/BashFAQ/006
>>
>
> I looked at the pageread every section that was >basic & some basic...
>
> nothing about using indirect variables with arrays... (let alone assigning
> to them)..
lies
Re: Syntax Question...
On Sun, Aug 14, 2011 at 04:55, Linda Walsh wrote:
>
>
>
> ` Michael Witten wrote:
>>
>> On Sat, Aug 13, 2011 at 23:41, Linda Walsh wrote:
>>
>>>
>>> ${#${!name}[*]}
>>> bash: ${#${!name}[*]}: bad substitution
>>>
>>
>> It's probably what you're trying to avoid, but you'll probably have to
>> construct and then eval the right code by hand:
>>
>> $(eval "echo \${#$name[*]}")
>>
>
> bingo. (sigh)
>
> I refactored and am essentially using spaces to store the values in
> a string, then when I want to check the, I throw them into an array and
> manip.
> e.g. (not showing all supporting code)
>
> declare -axr _plst_t='_plist_'
> declare -axl defined_PLists=()
>
> add things to the list...
>
> plist="$_plst_t$plist"
> local -al plist_deps=( $plist )
>
> {search for value in list, ...]
>
> unless ((found)) ; then
> plist_deps[${#plist_deps[*]}]="$subdep"
> eval "$plist=( "$plist_deps[@]" )"
> fi
You want this:
unless ((found)) ; then
plist_deps+=("$subdep")
eval $plist='("${plist_deps[@]}")'
fi
Of course, isn't the variable `plist' supposed to be a reference to
your *string* variable that holds a space-separated list of items? In
that case, the last line should be:
IFS=' ' eval $plist='"${a[*]}"'
Re: Syntax Question...
On Sun, Aug 14, 2011 at 05:56, Michael Witten wrote:
> On Sun, Aug 14, 2011 at 04:55, Linda Walsh wrote:
>>
>>
>>
>> ` Michael Witten wrote:
>>>
>>> On Sat, Aug 13, 2011 at 23:41, Linda Walsh wrote:
>>>
${#${!name}[*]}
bash: ${#${!name}[*]}: bad substitution
>>>
>>> It's probably what you're trying to avoid, but you'll probably have to
>>> construct and then eval the right code by hand:
>>>
>>> $(eval "echo \${#$name[*]}")
>>>
>>
>> bingo. (sigh)
>>
>> I refactored and am essentially using spaces to store the values in
>> a string, then when I want to check the, I throw them into an array and
>> manip.
>> e.g. (not showing all supporting code)
>>
>> declare -axr _plst_t='_plist_'
>> declare -axl defined_PLists=()
>>
>> add things to the list...
>>
>> plist="$_plst_t$plist"
>> local -al plist_deps=( $plist )
>>
>> {search for value in list, ...]
>>
>> unless ((found)) ; then
>> plist_deps[${#plist_deps[*]}]="$subdep"
>> eval "$plist=( "$plist_deps[@]" )"
>> fi
>
> You want this:
>
> unless ((found)) ; then
> plist_deps+=("$subdep")
> eval $plist='("${plist_deps[@]}")'
> fi
>
> Of course, isn't the variable `plist' supposed to be a reference to
> your *string* variable that holds a space-separated list of items? In
> that case, the last line should be:
>
> IFS=' ' eval $plist='"${a[*]}"'
Woops! That last line should read:
IFS=' ' eval $plist='"${plist_deps[*]}"'
Of course, if each list item is guaranteed never to contain a
word-delimiting character, then the quoting may be simplified.
In the first case:
unless ((found)) ; then
plist_deps+=($subdep)
eval $plist='(${plist_deps[@]})'
fi
and in the second case (where each list item is also guaranteed never
to contain a space character):
unless ((found)) ; then
plist_deps+=($subdep)
IFS=' ' eval $plist=\${plist_deps[*]}
fi
