Crontab timed task script does not execute, log has no execution record

In Linux under the crontab to start a timed script, put in the crontab of dead and dead did not respond, this is the possible reason:

1, look at the log, Cat/var/log/cron. If there is an execution record in the log, it may be that the script does not have permission to execute, giving execution permission, such as chmod +x xxx.sh, which gives the xxx.sh script permission to execute.

2, look at the log, no response to the log, no script execution record, crontab-l View list no problem, Crontab is also running state, the possible reason is that the editing time task with the Chinese space, the best solution crontab-e into the editing interface, the task was deleted to write again , remember, must not bring Chinese.

3, there may be a script at the beginning of the #!/bin/bash write wrong, such as #/bin/bash write less.

Some of the internet is caused by environmental variables, if the above methods do not work, you can Baidu environmental variables to solve the problem.