bash 检查字符串是否包含星号 (*)
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Check if a string contains Asterisk (*)
提问by voidAndAny
I want to check if my string contain one or more asterisk.
我想检查我的字符串是否包含一个或多个星号。
I have tried this :
我试过这个：
if [[ $date_alarm =~ .*\*.* ]]
then
...
fi
It worked when I launch directly the script, but not if this script is called during shutdown (script installed in run level 0 and 6 via update-rc.d)
它在我直接启动脚本时有效，但如果在关闭期间调用此脚本则无效（通过 update-rc.d 安装在运行级别 0 和 6 中的脚本）
Any idea, suggestion ?
任何想法，建议？
Thanks
谢谢
采纳答案by William Pursell
Always quote strings.
总是引用字符串。
To check if the string $date_alarm contains an asterisk, you can do:
要检查字符串 $date_alarm 是否包含星号，您可以执行以下操作：
if echo x"$date_alarm" | grep '*' > /dev/null; then
...
fi
回答by BreizhGatch
expr "$date_alarm" : ".*\*.*"
回答by reinierpost
case "$date_alarm" in
*\**)
...
break
;;
*)
# else part
...
;;
esac
The syntax is, well, /bin/sh, but it works.
语法是 /bin/sh，但它有效。
回答by voidAndAny
Finally
最后
if echo x"$date_alarm" | grep '*' > /dev/null; then
did the trick
成功了
Strange thing =~ .*.doesn't work only in init context during shutdown, but work perfectly if launch in bash context....
奇怪的东西=~。*. 不仅在关机期间在 init 上下文中工作，而且如果在 bash 上下文中启动，它也能完美工作......
回答by zigo
No need to redirect stdout like others do. Use the -q option of grep instead:
无需像其他人那样重定向标准输出。请改用 grep 的 -q 选项：
if echo x"$date_alarm" | grep -q '*' ; then
if echo x"$date_alarm" | grep -q '*' ; 然后
回答by Atmocreations
what happens if you replace
如果你更换会发生什么
if [[ $date_alarm =~ .*\*.* ]]
with
和
if [[ "$date_alarm" =~ .*\*.* ]]
you might also want to try:
您可能还想尝试：
if [[ "$date_alarm" =~ '\*+' ]]
not sure about that one...
不确定那个...
regards
问候
回答by chaos
if echo $date_alarm|perl -e '$_=<>;exit(!/\*/)'
then
...
fi
