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What is a thread exit code?
... returned from your process or thread as part of an exit code. The higher order bytes are used by the operating system to convey special information about the process. The exit code is very useful in batch/shell programs which conditionally execute other programs depending on the success or failur...
Why does Iterable not provide stream() and parallelStream() methods?
...Streams.stream(Spliterators.spliteratorUnknownSize(iterator,
Spliterator.ORDERED))
And then Brian Goetz responded:
I think Sam's point was that there are plenty of library classes that
give you an Iterator but don't let you necessarily write your own
spliterator. So all you can do is ca...
SQL - Rounding off to 2 decimal places
...
Seems to convert to string ? which screws up order by.
– blissweb
Mar 4 '18 at 2:08
2
...
Difference between Arrays.asList(array) and new ArrayList(Arrays.asList(array))
...l, if you overwrite an element, it gets overwritten in the original array, etc. Of course, some List operations aren't allowed on the wrapper, like adding or removing elements from the list, you can only read or overwrite the elements.
Note that the list wrapper doesn't extend ArrayList - it's a di...
How can I set the default timezone in node.js?
...
@FlavorScape I use Etc/UTC There are also specific offsets available in Etc, but the offset is reverse of what one would expect. Etc/GMT-1 is UTC + 1 hour. See https://en.wikipedia.org/wiki/List_of_tz_database_time_zones
...
Throwing the fattest people off of an overloaded airplane.
...y heap!
var myHeap = new MinHeap<Passenger>(/* need comparer here to order by weight */);
foreach (var pass in passengers)
{
if (totalWeight < targetTotal)
{
// unconditionally add this passenger
myHeap.Add(pass);
totalWeight += pass.Weight;
}
else if...
How to profile a bash shell script slow startup?
...another version that can output nanoseconds), do this at the beginning of /etc/bash.bashrc (or wherever you'd like to begin a trace in any Bash script):
PS4='+ $(date "+%s.%N")\011 '
exec 3>&2 2>/tmp/bashstart.$$.log
set -x
add
set +x
exec 2>&3 3>&-
at the end of ~/.bas...
How do you find the row count for all your tables in Postgres
...mate:
SELECT schemaname,relname,n_live_tup
FROM pg_stat_user_tables
ORDER BY n_live_tup DESC;
That can also show you how many rows are dead, which is itself an interesting number to monitor.
The third way is to note that the system ANALYZE command, which is executed by the autovacuum proce...
Running a cron every 30 seconds
...ice.
Here is a simple example that logs "Hello World" every 10 seconds:
/etc/systemd/system/helloworld.service:
[Unit]
Description=Say Hello
[Service]
ExecStart=/usr/bin/logger -i Hello World
/etc/systemd/system/helloworld.timer:
[Unit]
Description=Say Hello every 10 seconds
[Timer]
OnBootSec=...
Cron job every three days
... you want it to run on specific days of the month, like the 1st, 4th, 7th, etc... then you can just have a conditional in your script that checks for the current day of the month.
if (((date('j') - 1) % 3))
exit();
or, as @mario points out, you can use date('k') to get the day of the year inst...