Re: memory leak in bash only during boot up in Bash-3.2.48
Hi Chet, >What is the hard limit on the number of processes for a process started in >this environment? (The value of `ulimit -n'.) Here are the Hard and soft limits for open files and max user processes. root@localhost:/root> ulimit -Hn 1024 root@localhost:/root> ulimit -Hu 516046 root@localhost:/root> ulimit -Su 1024 root@localhost:/root> ulimit -Sn 1024 Regards, Abhishek On Fri, Dec 21, 2018 at 10:20 PM Chet Ramey wrote: > On 12/19/18 12:54 AM, abhishpaliwal wrote: > > create a shell script from below given code. name it testing.sh. > > > > #!/bin/bash > > logger "Started testing" > > while(true); do > > while (true); do ls > /dev/null ; done > > done > > > > Steps. > > # chmod 755 /root/testing.sh > > modify any /etc/init.d/"service" file add "/root/testing.sh" inside the > > start case. > > "service" is any service file starting during start up. > > Make sure above service is started during the startup. > > What is the hard limit on the number of processes for a process started in > this environment? (The value of `ulimit -n'.) > > -- > ``The lyf so short, the craft so long to lerne.'' - Chaucer > ``Ars longa, vita brevis'' - Hippocrates > Chet Ramey, UTech, CWRUc...@case.eduhttp://tiswww.cwru.edu/~chet/ > -- Regards Abhishek Paliwal
Re: Error on arithmetic evaluation of `~0`.
On 12/19/18 10:31 PM, Bize Ma wrote:
> This is the third time I am reporting this issue.
Not really, but let's go on.
>
> This fails:
>
> var=(hello); echo "${var[~0]}"
> syntax error: operand expected ...
Yes. The comment in the code says:
"Right now, the code
suppresses tilde expansion when expanding in a pure arithmetic
context, but allows it when expanding an array subscript. This is
for backwards compatibility, but I figure nobody's relying on it"
I suppose backwards compatibility here is less important at this point.
>
> While this works:
>
> var=(hello); echo "${var[ ~0]}"
> hello
Because negative array subscripts count backwards from the end of the
array.
> It is also interesting that this fails:
>
> var=hello; echo "${var[ ~0]}"
> bash: var: bad array subscript
>
> Isn't `var[0]` valid and equivalent to `var` ?
Yes, but ~0 (-1) is not the same as 0.
> This was "supposed" to be resolved in a dev version,
> but is still present on bash 5.
The other arithmetic contexts you reported (the "pure" arithmetic contexts
the comment above references) were changed; this was left for backwards
compatibility. Like I said above, it looks like it's time to deemphasize
that.
Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRUc...@case.eduhttp://tiswww.cwru.edu/~chet/
Re: Error on arithmetic evaluation of `~0`.
On 12/20/18 8:12 AM, Greg Wooledge wrote: > The issue you're reporting appears to be present in arithmetic contexts > in general, not only arrays: > > wooledg:~$ echo $((~0)) > bash: /home/wooledg: syntax error: operand expected (error token is > "/home/wooledg") This is what was fixed post-bash-4.4. I left the array subscript expansion unchanged for backwards compatibility. > It appears that bash is performing tilde expansion when there's no > whitespace in front of the tilde, or bitwise negation if there is > whitespace. Because tilde expansion only happens on the first character of a string, or following an unquoted `=' or `:'. Chet -- ``The lyf so short, the craft so long to lerne.'' - Chaucer ``Ars longa, vita brevis'' - Hippocrates Chet Ramey, UTech, CWRUc...@case.eduhttp://tiswww.cwru.edu/~chet/
