How to solve the problem that ubuntu crontab does not execute
This article mainly explains "how to solve the problem of non-implementation of ubuntu crontab". The content of the explanation is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn "how to solve the problem of non-implementation of ubuntu crontab".
Add the following sentence to the second line of the script file
The code is as follows:
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
Here are the steps to analyze and solve the problem:
1. The reason for non-execution is caused by environment variables.
two。 Currently, no default environment variable configuration method for configuring cron has been found
Vim / etc/crontab can see that the environment variables in this file are correct
3. * / root/test.sh > ifconfig.txt 2 > & 1 & test.sh is executed every minute
The content of test.sh is as follows. You can see that the output environment variable is / usr/bin:/bin.
The code is as follows:
#! / bin/bash
# PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
Ifconfig
Echo $PATH
Output:
The code is as follows:
/ root/test.sh: line 3: ifconfig: command not found
/ usr/bin:/bin
4. View the location of ifconfig
The code is as follows:
Root@ubuntu:~# whereis ifconfig
Ifconfig: / sbin/ifconfig / usr/share/man/man8/ifconfig.8.gz
5. Comment out the second line of the test.sh script and you can see that the output is as follows
The code is as follows:
Eth0 Link encap:Ethernet HWaddr aa:00:04:00:0a:04
Inet addr:192.168.1.60 Bcast:0.0.0.0 Mask:255.255.255.0
Inet6 addr: fe80::20c:29ff:fef8:73b6/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2093659 errors:0 dropped:0 overruns:0 frame:0
TX packets:1532815 errors:0 dropped:0 overruns:0 carrier:0
Collisions:0 txqueuelen:1000
RX bytes:519122457 (519.1 MB) TX bytes:447226592 (447.2 MB)
Lo Link encap:Local Loopback
Inet addr:127.0.0.1 Mask:255.0.0.0
Inet6 addr: 1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:433596 errors:0 dropped:0 overruns:0 frame:0
TX packets:433596 errors:0 dropped:0 overruns:0 carrier:0
Collisions:0 txqueuelen:0
RX bytes:23228192 (23.2MB) TX bytes:23228192 (23.2MB)
/ usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
The 6.test.sh script only temporarily changes the value of PATH. It only takes effect on the current script.
Thank you for your reading, the above is the content of "how to solve the problem of non-implementation of ubuntu crontab". After the study of this article, I believe you have a deeper understanding of how to solve the problem of non-implementation of ubuntu crontab, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!
