I've following simple while loop code in groovy -
def count = 1
while(count <= 5) {
println "$count"
sleep(5000)
println "Sleeping for 5 seconds"
count++
}
Which indicates that loop is executed only twice still second time Sleeping for 5 seconds is not run. Actually with this code, while block is expected to be executed 5 times. Can someone help to understand why such a weird behaviour?
When this code is run, output is following -
1
Sleeping for 5 seconds
2
This works fine:
~ $ cat doit.groovy
def count = 1
while(count <= 5) {
println "$count"
sleep(5000)
println "Sleeping for 5 seconds"
count++
}
~ $ groovy doit
1
Sleeping for 5 seconds
2
Sleeping for 5 seconds
3
Sleeping for 5 seconds
4
Sleeping for 5 seconds
5
Sleeping for 5 seconds
Related
My script should have n subroutines (my_proc) to run simultaneously, each of them runs bash script and one sub (check_procs) checks if subs has finished.
use strict;
use threads;
use threads::shared;
my %proc_status :shared;
my %thr;
foreach my $i (1,2,3,4) {
$proc_status{$i}=0;
}
sub my_proc {
my $arg=shift(#_);
while (1) {
sleep(2);
print "Proc $arg Started\n";
#exec("/bin/bash","sleep_for_10_sec.bash") or die("Can't exec"); # case 1
#`sleep_for_10_sec.bash &`; # case 2
print "Proc $arg Finished\n";
{
lock(%proc_status);
$proc_status{$arg}=1;
}
}
}
sub check_procs {
my $all_finished;
while (! $all_finished) {
sleep 5;
print "CHECK: \n";
$all_finished=1;
foreach my $num (1,2,3,4) {
if ($proc_status{$num} == 1) {
print "CHECK: procedure $num has finished\n";
} else {
$all_finished=0;
}
}
}
print "All jobs finished\n";
}
foreach my $num (1,2,3,4) {
$thr{"$num"} = new threads \&my_proc,$num;
}
my $thr_check= new threads \&check_procs;
$thr_check->join();
And here are the sleep_for_10_sec.bash
ls
# bunch of other stuff
sleep 10
echo "finished sleep"
I don't want my_proc subs to wait "sleep_for_10_sec.bash" command to be executed, after browsing I have found that either #case1 or #case2 should work, but they both fail.
the output of #case1:
Proc 1 Started
[ls result]
finsihed sleep
the output of #case2:
Proc 1 Started
Proc 2 Started
Proc 3 Started
Proc 4 Started
CHECK:
CHECK:
Proc 4 Finished
Proc 2 Finished
Proc 3 Finished
Proc 1 Finished
Proc 3 Started
Proc 1 Started
Proc 2 Started
Proc 4 Started
CHECK:
CHECK: procedure 1 has finished
CHECK: procedure 2 has finished
CHECK: procedure 3 has finished
CHECK: procedure 4 has finished
But I expect something like this :
Proc 1 Started
Proc 2 Started
Proc 3 Started
Proc 4 Started
Proc 1 Finished
Proc 1 Started
Proc 3 Finished
Proc 3 Started
Proc 4 Finished
Proc 4 Started
Proc 2 Finished
Proc 2 Started
CHECK:
CHECK:
CHECK:
CHECK: procedure 1 has finished
CHECK: procedure 2 has finished
CHECK: procedure 3 has finished
CHECK: procedure 4 has finished
Actually I get wanted result in case of redirecting output to " > log", but anyway after:
Proc 1 Started
Proc 2 Started
Proc 3 Started
Proc 4 Started
it waits "sleep_for_10_sec.bash" to finish.
This is my first project where I use "thread" and "exec", could someone help me on this ?
exec shouldn't be combined with threads. exec launches a new program within the current process, so when you call exec from one thread, the program the threads were executing disappears. Since the threads would have no program to execute, exec kills the threads as well.
It's not clear to me why case 2 doesn't work (edit: see ikegami's comment below). I would think it would launch the process, run it in the background, and allow the Perl thread to immediately continue. It doesn't seem to do that, but this code will:
system("/bin/bash sleep_for_10_sec.bash &"); # case 3
exec("/bin/bash","sleep_for_10_sec.bash") or die("Can't exec"); # case 1
exec replaces the program running in the current process with another program. At the same time, the existing threads are terminated (since the program they want to execute is no longer there), replaced with a single thread executing the new program.
This means that exec never returns (except on error). Threads or no threads, exec is not what you want, because you don't want your program to stop running.
But I expect something like this:
Are you sure you want to launch sleep_for_10_sec.bash 4 times every two seconds (meaning you can have up to 20 of them running at a time) as your desired output indicates?
Are you sure you don't care if sleep_for_10_sec.bash completes or not as your desired output indicates?
If so, why are you using threads at all? You could simply use the following:
sub start {
my $num = shift;
say "Proc $num Started";
system('bash -c sleep_for_10_sec.bash &');
say "Proc $num Finished";
}
for my $pass (1..2) {
start($_) for 1..4;
sleep 2;
start($_) for 1..4;
sleep 2;
start($_) for 1..4;
sleep 1;
if ($pass == 1) {
say "CHECK:";
} else {
say "CHECK: procedure $_ has finished" for 1..4;
}
}
I think you want
use threads;
use Thread::Queue qw( ); # 3.01+
use constant NUM_WORKERS => 4;
sub worker {
my $num = shift;
say "Job $num Started\n";
system("sleep_for_10_sec.bash"); # Make sure starts with #! and is executable.
say "Job $num Finished\n";
}
{
my $q = Thread::Queue->new();
for (1..NUM_WORKERS) {
while (defined( my $job = $q->dequeue() )) {
worker($job);
}
}
$q->enqueue(1..4, 1..4);
$q->end();
$_->join() for threads->list;
}
I have a file named countdown on my computer and I am trying to get it to countdown from what ever the user puts in.
for example ./countdown 5 would cause a 5 second timer to start outputting a "." every second and prints done after 5 seconds.
./countdown 10 would cause a 10 second timer to start outputting "." every second and prints done after 10 seconds.
here is my code, how can i read what the user inputs
t=$((5))
while [ $t -gt 0 ]; do
echo -ne "."
sleep 1
: $((t--))
done
echo "done"
Just change t=$((5)) to t=$1, which will assign the first argument to t.
I'm looking for a bash script that can parse a time duration.
If three arguments are given, they represent hours, minutes, and seconds. If two arguments are given, they represent minutes and seconds, with the hours zero.
What about the following:
#!/bin/bash
h=0
if [ "$#" -ge 3 ]
then
h=$1
shift
fi
sec=$((3600*$h+60*$1+$2))
echo "The total number of seconds is $sec"
Since the question does not specify what you aim to do with the given time, the program calculates the total number of seconds. Furthermore perhaps it is useful to do a check if at least two arguments are given.
The script uses the shift operation, the shift makes makes $1 := $2; $2 := $3, etc. In other words, the first argument is processed, and then you "pretend" it never existed.
By default you set h to zero, and only if the number of arguments is greater than or equal to 3, it will set h.
This is a more or less general solution for that type of task. Sorry, if it is a monkeycode, but I think it is sufficient:
gettime() {
params=(
years months weeks days hours minutes seconds
)
for i in `seq ${#params}`; do
param_i=$((${#params} - i + 1)) # reversed params index
[ $i -le $# ] && {
eval "local ${params[$param_i]}=\$$(($# - i + 1))"
} || {
eval "local ${params[$param_i]}=0"
}
eval "echo ${params[$param_i]} '==' \$${params[$param_i]}" # debug output
done
}
Here's the sample output:
$ gettime 3 4 5 6 7
seconds == 7
minutes == 6
hours == 5
days == 4
weeks == 3
months == 0
years == 0
Note, that the shell you are using must be not only support POSIX standards, but also arrays.
First Argument: $1
Second Argument: $2
Third Argument: $3
and so on...
Example:
bash-2.05a$ ./parseDuration.sh 13 25 25
13 hours and 25 minutes and 25 seconds
bash-2.05a$ cat ./parseDuration.sh
#!/bin/bash
echo "$1 hours and $2 minutes and $3 seconds"
I'm new to bash scripting and I faced an issue when I tried to improve my script. My script is spliting a text file and each part of this text file is processed in a function ... Everything is working fine but my problem occurs when I'm forking (with &) my function processing ! My args are not like expected (it's a line number and text with whitespaces and backspaces) and I suppose it's because of global variables ... I tried to fork, then sleep 1 second in the parent thread and then continue in order to put args into local variables for my function execution but it doesn't work either ... Can you give me a hint about how to do it ? What I want is to be able to pass args to my function and be allowed to modify it after the fork call in my parent thread ... is it possible ?
Thanks in advance :)
Here is my script :
#!/bin/bash
#Parameters#
FILE='tasks'
LINE_BY_THREAD='500'
#Function definition
function checkPart() {
local NUMBER="$1"
local TXT="$2"
echo "$TXT" | { while IFS= read -r line ; do
IFS=' ' read -ra ADDR <<< "$line"
#If the countdown is set to 0, launch the task ans set it to init value
if [ ${ADDR[0]} == '0' ]; then
#task launching
#to replace by $()l
echo `./${ADDR[1]}.sh ${ADDR[2]} &`
#countdown set to init value
sed -i "$NUMBER c ${ADDR[3]} ${ADDR[1]} ${ADDR[2]} ${ADDR[3]}" $FILE
else
sed -i "$NUMBER c $((ADDR-1)) ${ADDR[1]} ${ADDR[2]} ${ADDR[3]}" $FILE
fi
((NUMBER++))
done }
}
#Init processes number#
LINE_NUMBER=$(wc -l < $FILE)
NB_PROCESSES=$(($LINE_NUMBER / $LINE_BY_THREAD))
if [ $(($LINE_NUMBER % $LINE_BY_THREAD)) -ne '0' ]; then
((NB_PROCESSES++))
fi
echo "Number of thread to be run : $NB_PROCESSES"
#Start the split sequence#
for (( i = 2; i <= $LINE_NUMBER; i += $LINE_BY_THREAD ))
do
PARAM=$(sed "$i,$(($i + $LINE_BY_THREAD - 1))!d" "$FILE")
(checkPart "$i" "$PARAM") &
sleep 1
done
My job is to create a scheduler for tasks described in this following file :
#MinutesBeforeLaunch#TypeOfProcess#Argument#Frequency#
2 agr_m 42 5
5 agr_m_s 26 5
0 agr_m 42 5
3 agr_m_s 26 5
0 agr_m 42 5
5 agr_m_s 26 5
4 agr_m 42 5
5 agr_m_s 26 5
4 agr_m 42 5
4 agr_m_s 26 5
2 agr_m 42 5
4 agr_m_s 26 5
When I'm reading a number > 0 in the first column, I just decrement it and when it's a 0 I have to launch the task and set the first number to frequency, last column ...
My first code is the previous with sed for text replacement but is it possible to do better ?
How can I run cron every 1 second? there's only minutes option by default
Let cron start the job one time, the first time. Put the program in an infinite loop, sleep() for 1 second at the end of each loop. like this, in C:
int main( int argc, char ** argv ) {
while (1) {
// do the work
sleep(1000);
}
}
Could that work?
Cron executes stuff every minute. Use a script:
while :
do
sleep 1
some_command || break
done
or in one line:
while : ; do sleep 1 ; some_command || break ; done
This will wait 1 second in between each execution, so if your command takes .75 seconds to run, then this script will kick it off every 1.75 seconds.
You can't with cron, because 1 minute is THE minimum time interval available. You'd have to run a script that fires up 60 other scripts, with delays of 0 to 59 seconds, or a single script which re-runs itself 60 times.
But at that point, why not just run a single script outside of cron which does sleep(1) in a loop?