Re: [Help-bash] How to print a bash variable in the most succinct way?

[Chet Ramey]

On 8/16/16 9:21 PM, Peng Yu wrote:
> On Tue, Aug 16, 2016 at 8:13 PM, Chet Ramey <address@hidden> wrote:
>> On 8/16/16 4:54 PM, Peng Yu wrote:
>>> On Tue, Aug 16, 2016 at 2:56 PM, Chet Ramey <address@hidden> wrote:
>>>> On 8/16/16 3:21 PM, Peng Yu wrote:
>>>>
>>>>>
>>>>> How to only generate variables that are modifiable (i.e., not readonly)?
>>>>
>>>> Generate a list of all variables.  Generate a list of readonly variables.
>>>
>>> How to generate a list of the names of the readonly variables?
>>> `readonly` will print both the names and their values. I will run into
>>> the same problem when there are $'\n' in their values.
>>
>> Use the toolset.
>>
>> readonly -p | grep = | sed 's|^declare.* \([[:upper:][:lower:]_]*\)=.*$|\1|'
>> readonly -p | awk '$0 ~ "declare.*" {print $3}' | sed
>> 's|[^[:upper:][:lower:]_].*$||'
> 
> These commands won't work robustly as shown below.

Then modify them.  You have to do some of the work yourself here.

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    address@hidden    http://cnswww.cns.cwru.edu/~chet/