bash脚本产生比由cron执行从shell提示符下执行时不同的结果 [英] Bash script produces different result when executed from shell prompt than executed by cron
问题描述
请考虑以下的crontab(根):
Please consider following crontab (root):
SHELL=/bin/bash
...
...
0 */3 * * * /var/maintenance/raid.sh
而bash脚本 /var/maintenance/raid.sh
:
#!/bin/bash
echo -n "Checking /dev/md0... "
if ! [ $(mdadm --detail /dev/md0 | grep -c "active sync") -eq 2 ]; then
mdadm --detail /dev/md0 | mail -s "Raid problem /dev/md0" "my@email.com";
echo "ERROR"
else
echo "ALL OK"
fi;
#-------------------------------------------------------
echo -n "Checking /dev/md1... "
...
,这是什么时候发生的?
...从shell提示符(bash)的执行:
与的mdadm --detail的/ dev / md0的
输出邮件发送到我的邮箱(正确的行为)
Mail with mdadm --detail /dev/md0
output is sent to my email (proper behaviour)
...由cron执行:
空白邮件发送到我的邮箱(主题是存在的,但没有消息)
Blank mail is sent to my email (subject is there, but there is no message)
为什么会有如此的差异,以及如何解决它?
Why such difference and how to fix it?
推荐答案
如图所示<一个href=\"http://stackoverflow.com/questions/18912018/bash-script-produces-different-result-when-executed-from-shell-prompt-than-execu?noredirect=1#comment27919070_18912018\">in该评论,确实使用上的crontab脚本完整路径,因为crontab中确实有比普通用户(在这种情况下,根)不同的环境变量
As indicated in the comments, do use full paths on crontab scripts, because crontab does have different environment variables than the normal user (root in this case).
在你的情况,而不是的mdadm
, / sbin目录/ mdadm的
使得它。
In your case, instead of mdadm
, /sbin/mdadm
makes it.
如何获得命令的完整路径?使用命令这
:
How to get the full path of a command? Using the command which
:
$ which rm
/bin/rm
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