crontab

I need to set up a cron job that runs an executable compiled using gcc once every hour. I logged in as root and typed crontab -e Then I entered the following and saved the file. 0 * * * * /path_to_executable However, the cron job does not work. I see that when I type /...path_to_executable I get a segmentation fault. I can only execute the executable from the folder it is located in. Is there a way I can solve this problem? 0 * * * * cd folder_containing_exe && ./exe_name should work unless there is something else that needs to be setup for the program to run. David Thornley The solution to

I would like to set a job to run daily in the root crontab. But I would like it to execute it from a particular directory so it can find all the files it needs, since the application has a bunch of relative paths. Anyway, can I tell crontab to run from a particular directory? Gilles All jobs are executed by a shell, so start that shell snippet by a command to change the directory. cd /path/to/directory && ./bin/myapp Concerning the use of && instead of ; : normally it doesn't make a difference, but if the cd command fails (e.g. because the directory doesn't exist) with && the application isn't

Do I have to restart cron after changing the crontable file? leonbloy No. From the cron man page : ...cron will then examine the modification time on all crontabs and reload those which have changed. Thus cron need not be restarted whenever a crontab file is modified But if you just want to make sure its done anyway, sudo service cron reload or /etc/init.d/cron reload Sheldmandu On CentOS with cPanel sudo /etc/init.d/crond reload does the trick. On CentOS7: sudo systemctl start crond.service Gyro I had a similar issue on 16.04 VPS Digital Ocean. If you are changing crontabs, make sure to run

crontab的语法： 　　 crontab各参数说明： 　　-e : 执行文字编辑器来编辑crontab，内定的文字编辑器是VI 　　-r : 删除目前的crontab 　　-l : 列出目前的crontab(查看专用) 　　-i : 会和-r 配合使用，在删除当前的crontab时询问，输入y 则删除 　　注意crontab是分用户的，以谁登录就会编辑到谁的crontab 　　 crontab特殊的符号说明： 　　"*"代表所有的取值范围内的数字。特别要注意哦! 　　"/"代表每的意思，如"*/5"表示每5个单位 　　"-"代表从某个数字到某个数字 　　","分散的数字 　　crontab文件的使用示例： 　　30 21 * * * 表示每晚的21:30 　　45 4 1,10,22 * * 表示每月1、10、22日的4 : 45 　　10 1 * * 6,0 表示每周六、周日的1 : 10 　　0,30 18-23 * * * 表示在每天18 : 00至23 : 00之间每隔30分钟 　　0 23 * * 6 表示每星期六的11 : 00 pm 　　* */1 * * * 每一小时 　　* 23-7/1 * * * 晚上11点到早上7点之间，每隔一小时 　　* 8,13 * * 1-5 从周一到周五的上午8点和下午1点 　　0 11 4 * mon-wed

I have a cron issue with curl : curl -w "%{time_total}\n" -o /dev/null -s http://myurl.com >> ~/log works great and add a line in log file with total_time. But the same line with cron doesn't do anything. It's not a path problem because curl http://myurl.com >> ~/log works. fedorqui % is a special character for crontab . From man 5 crontab : The "sixth" field (the rest of the line) specifies the command to be run. The entire command portion of the line, up to a newline or a "%" character, will be executed by /bin/sh or by the shell specified in the SHELL variable of the cronfile. A "%"

为了日志写入权限的问题，计划任务统一使用nginx用户运行 编辑计划任务使用命令： crontab -u nginx -e 参考： http://www.bcty365.com/content-153-6160-1.html https://blog.csdn.net/xuntianzong/article/details/22279911 来源： https://www.cnblogs.com/zqsb/p/11382154.html

我的做法： !/bin/bash Available=`df -k | sed -n 2p | awk '{print $4}'` if [ $Available -eq 0 ];then `echo '' > /home/wwwlogs/bes-req.log` fi 参考资料： #!/bin/bash #取得每个分区的使用百分比（不要百分号） percent=`df -k | grep -v Filesystem| awk '{print int($5)}' ` #循环判断分区使用率是否超过90% for each_one in $percent do #判断使用率是否超过90% if [ $each_one -ge 90 ];then #如果超过90 则把使用情况发给mail_address mail_address换成你的邮件地址 df | mail -s "Disk Critical" mail_address fi done 配合shell 的crontab功能，不能写java代码就可以迅速实现功能 一 cron crond位于/etc/rc.d/init.d/crond 或 /etc/init.d 或 /etc/rc.d /rc5.d/S90crond,最总引用/var/lock/subsys/crond。 cron是一个linux下的定时执行工具