每30秒执行一次cron

#1 楼

# Need these to run on 30-sec boundaries, keep commands in sync.
* * * * *              /path/to/executable param1 param2
* * * * * ( sleep 30 ; /path/to/executable param1 param2 )

#!/bin/env bash

# Debug code to start on minute boundary and to
# gradually increase maximum payload duration to
# see what happens when the payload exceeds 30 seconds.

((maxtime = 20))
while [[ "$(date +%S)" != "00" ]]; do true; done

while true; do
    # Start a background timer BEFORE the payload runs.

    sleep 30 &

    # Execute the payload, some random duration up to the limit.
    # Extra blank line if excess payload.

    ((delay = RANDOM % maxtime + 1))
    ((maxtime += 1))
    echo "$(date) Sleeping for ${delay} seconds (max ${maxtime})."
    [[ ${delay} -gt 30 ]] && echo
    sleep ${delay}

    # Wait for timer to finish before next cycle.

    wait
done

Tue May 26 20:56:00 AWST 2020 Sleeping for 9 seconds (max 21).
Tue May 26 20:56:30 AWST 2020 Sleeping for 19 seconds (max 22).
Tue May 26 20:57:00 AWST 2020 Sleeping for 9 seconds (max 23).
Tue May 26 20:57:30 AWST 2020 Sleeping for 7 seconds (max 24).
Tue May 26 20:58:00 AWST 2020 Sleeping for 2 seconds (max 25).
Tue May 26 20:58:30 AWST 2020 Sleeping for 8 seconds (max 26).
Tue May 26 20:59:00 AWST 2020 Sleeping for 20 seconds (max 27).
Tue May 26 20:59:30 AWST 2020 Sleeping for 25 seconds (max 28).
Tue May 26 21:00:00 AWST 2020 Sleeping for 5 seconds (max 29).
Tue May 26 21:00:30 AWST 2020 Sleeping for 6 seconds (max 30).
Tue May 26 21:01:00 AWST 2020 Sleeping for 27 seconds (max 31).
Tue May 26 21:01:30 AWST 2020 Sleeping for 25 seconds (max 32).
Tue May 26 21:02:00 AWST 2020 Sleeping for 15 seconds (max 33).
Tue May 26 21:02:30 AWST 2020 Sleeping for 10 seconds (max 34).
Tue May 26 21:03:00 AWST 2020 Sleeping for 5 seconds (max 35).
Tue May 26 21:03:30 AWST 2020 Sleeping for 35 seconds (max 36).

Tue May 26 21:04:05 AWST 2020 Sleeping for 2 seconds (max 37).
Tue May 26 21:04:35 AWST 2020 Sleeping for 20 seconds (max 38).
Tue May 26 21:05:05 AWST 2020 Sleeping for 22 seconds (max 39).
Tue May 26 21:05:35 AWST 2020 Sleeping for 18 seconds (max 40).
Tue May 26 21:06:05 AWST 2020 Sleeping for 33 seconds (max 41).

Tue May 26 21:06:38 AWST 2020 Sleeping for 31 seconds (max 42).

Tue May 26 21:07:09 AWST 2020 Sleeping for 6 seconds (max 43).

#2 楼

* * * * * cd /srv/last_song/releases/20120308133159 && script/rails runner -e production '\''Song.insert_latest'\''
* * * * * sleep 30 && cd /srv/last_song/releases/20120308133159 && script/rails runner -e production '\''Song.insert_latest'\''

#3 楼

[Unit]
Description=Say Hello
[Service]
ExecStart=/usr/bin/logger -i Hello World

[Unit]
Description=Say Hello every 10 seconds
[Timer]
OnBootSec=10
OnUnitActiveSec=10
AccuracySec=1ms
[Install]
WantedBy=timers.target

OnCalendar=*-*-* *:*:00,10,20,30,40,50

#4 楼

#!/bin/env bash
while [ true ]; do
 sleep 30
 # do what you need to here
done

#5 楼

* * * * * /bin/bash -l -c "/path/to/executable; sleep 30 ; /path/to/executable"

#6 楼

$ cat every-5-seconds.sh
#!/bin/bash
while true
do
 /home/ramesh/backup.sh
 sleep 5
done

$ nohup ./every-5-seconds.sh &

#7 楼

#8 楼

$ watch --interval .30 script_to_run_every_30_sec.sh

#9 楼

* * * * * /bin/bash -c ' for i in {1..X}; do YOUR_COMMANDS ; sleep Y ; done '

#10 楼

#11 楼

* * * * * yourusername  /bin/date >> /home/yourusername/temp/date.txt
* * * * * yourusername sleep 30; /bin/date >> /home/yourusername/temp/date.txt

#12 楼

#!/bin/bash
# 30sec.sh

for COUNT in `seq 29` ; do
  cp /application/tmp/* /home/test
  sleep 30
done

* * * * * /home/test/30sec.sh > /dev/null

#13 楼

#!/bin/bash
For  (( i=1; i <= 2; i++ ))
do
    write Command here
    sleep 30
done

#14 楼

sudo vim /etc/systemd/system/YOUR_SERVICE_NAME.service

Description=GIVE_YOUR_SERVICE_A_DESCRIPTION

Wants=network.target
After=syslog.target network-online.target

[Service]
Type=simple
ExecStart=YOUR_COMMAND_HERE
Restart=always
RestartSec=10
KillMode=process

[Install]
WantedBy=multi-user.target

sudo systemctl daemon-reload

sudo systemctl enable YOUR_SERVICE_NAME

sudo systemctl start YOUR_SERVICE_NAME

systemctl status YOUR_SERVICE_NAME

#15 楼

 * * * * 1-6 ./a/b/checkAgendaScript >> /home/a/b/cronlogs/checkAgenda.log

cd /home/a/b/checkAgenda

java -jar checkAgenda.jar
sleep 20
java -jar checkAgenda.jar 
sleep 20
java -jar checkAgenda.jar 

#16 楼

nohup watch -n30 "kill -3 NODE_PID" &

nohup ... & 

#17 楼

#18 楼

#!/bin/sh    
counter=1
while true ; do
 echo $counter
 counter=$((counter+1))
 if [[ "$counter" -eq 60 ]]; then
  counter=0
 fi
 wget -q http://localhost/tool/heartbeat/ -O - > /dev/null 2>&1 &
 sleep 1
done

#19 楼

0 * * * * /bin/bash -l -c 'cd /srv/last_song/releases/20120308133159 && script/rails runner -e production '\''Song.insert_latest'\'''
30 * * * * /bin/bash -l -c 'cd /srv/last_song/releases/20120308133159 && script/rails runner -e production '\''Song.insert_latest'\'''