scipt內用eval無法執行特定指令 - Linux
By Lily
at 2019-05-30T10:55
at 2019-05-30T10:55
Table of Contents
我想寫一個script 偵測某台機器的5432 port
搭配 keepalived 使用
指令長這樣
</dev/tcp/127.0.0.1/80
對,就這樣而已,如果直接在shell 底下執行,正常的話就不會有輸出
但是我直接加到 keepalived.conf 裡面,會說找不到這指令
Script </dev/tcp/192.168.11.34/5432 cannot be accessed - No such file or directory
所以我想說用script 來跑
script 也很簡單,就是跑上面那行指令
#!/bin/sh
COMMAND="</dev/tcp/127.0.0.1/80"
echo "$COMMAND"
eval "</dev/tcp/127.0.0.1/80"
執行結果
/tmp/check_psql.sh
</dev/tcp/127.0.0.1/80
/tmp/check_psql.sh: 1: eval: cannot open /dev/tcp/127.0.0.1/80: No such file
指令格式應該沒有錯,可是eval 少了一個 "<" 所以我改了一下,加入escape "\"
變成這樣
/tmp/check_psql.sh
</dev/tcp/127.0.0.1/80
/tmp/check_psql.sh: 1: eval: </dev/tcp/127.0.0.1/80: not found
所以指令格式正確了,可是還是沒辦法順利執行
不曉得該怎麼修正呢?
或者是有其他指令可以偵測特定port 是否活著?
--
搭配 keepalived 使用
指令長這樣
</dev/tcp/127.0.0.1/80
對,就這樣而已,如果直接在shell 底下執行,正常的話就不會有輸出
但是我直接加到 keepalived.conf 裡面,會說找不到這指令
Script </dev/tcp/192.168.11.34/5432 cannot be accessed - No such file or directory
所以我想說用script 來跑
script 也很簡單,就是跑上面那行指令
#!/bin/sh
COMMAND="</dev/tcp/127.0.0.1/80"
echo "$COMMAND"
eval "</dev/tcp/127.0.0.1/80"
執行結果
/tmp/check_psql.sh
</dev/tcp/127.0.0.1/80
/tmp/check_psql.sh: 1: eval: cannot open /dev/tcp/127.0.0.1/80: No such file
指令格式應該沒有錯,可是eval 少了一個 "<" 所以我改了一下,加入escape "\"
變成這樣
/tmp/check_psql.sh
</dev/tcp/127.0.0.1/80
/tmp/check_psql.sh: 1: eval: </dev/tcp/127.0.0.1/80: not found
所以指令格式正確了,可是還是沒辦法順利執行
不曉得該怎麼修正呢?
或者是有其他指令可以偵測特定port 是否活著?
--
Tags:
Linux
All Comments
By Yedda
at 2019-06-03T09:11
at 2019-06-03T09:11
By Rosalind
at 2019-06-07T11:06
at 2019-06-07T11:06
By Noah
at 2019-06-08T04:31
at 2019-06-08T04:31
By Zanna
at 2019-06-08T23:19
at 2019-06-08T23:19
By Oscar
at 2019-06-09T20:39
at 2019-06-09T20:39
By Emma
at 2019-06-10T15:20
at 2019-06-10T15:20
By Faithe
at 2019-06-15T12:17
at 2019-06-15T12:17
By Skylar DavisLinda
at 2019-06-16T16:24
at 2019-06-16T16:24
By Lauren
at 2019-06-20T16:49
at 2019-06-20T16:49
By Catherine
at 2019-06-22T19:22
at 2019-06-22T19:22
By Zanna
at 2019-06-27T01:40
at 2019-06-27T01:40
By Tom
at 2019-07-01T19:32
at 2019-07-01T19:32
By Tracy
at 2019-07-05T23:40
at 2019-07-05T23:40
Related Posts
By Robert
at 2019-05-30T07:34
at 2019-05-30T07:34
sed取指定字串中的特定子字串
By Noah
at 2019-05-30T00:07
at 2019-05-30T00:07
雙硬碟雙系統 如何跳過grub?
By Yuri
at 2019-05-28T22:48
at 2019-05-28T22:48
openSUSE Leap 15.1 Out Now!
By Olga
at 2019-05-28T12:38
at 2019-05-28T12:38
老電腦進桌面前要先亂按鍵盤
By Leila
at 2019-05-26T21:01
at 2019-05-26T21:01