Shell script Execution Conflict event-ssh&while

Today we find a problem: Read the following script: [email protected]/0 # cat ! $cat  /tmp/test_nginxls *.txt |  tr  '   '   ' \ n '  | while read linedo echo  $lineif  [  ' Yes '  ==  ' yes '  ]thenssh  192.168.109.10  ' echo  ' yes ' "elsessh  192.168.109.10  "echo  ' no '" fidone the script above is simple, read all the TXT-terminated files in the current directory (actually I just get the loop number), but we run the script to see that the script exits only once. The effect is as follows:[email protected]/0 # bash -x /tmp/test_nginx        + tr  '   '   ' \ n ' + ls 1.txt 2.txt ip.txt png.txt        + read line+ echo 1.txt1.txt+  ' ['  yes = = yes  ' + ssh 192.168.9.10  ' echo  ' ' yes ' ' yes+ read line now congratulations, You have come into contact with the ssh  and while  conflict! The approach is always more problematic. The solution is simple: Method one:  ssh  192.168.109.10  "echo  ' yes '"      changed to &NBSP; ssh  192.168.109.10  "echo  ' Yes '"   < /dev/null   method two:   ssh  192.168.109.10  "echo  ' yes '"      change to   ssh   -n 192.168.109.10  "echo  ' yes '"       causes:ssh  The command reads a loop that is not executed while the following content can help you understand it. [Email protected]/0 # bash -x /tmp/test_nginx + ls 1.txt 2.txt  ip.txt png.txt+ tr  '   '   ' \ n ' + read line+ echo 1.txt1.txt+   ' ['  yes == yes  '] ' + ssh 192.168.9.10 cat      //we change the order to cat, we'll find out. 2.txtip.txtpng.txt+ read line

This article is from the Linux system maintenance blog, so be sure to keep this source http://linuxadmin.blog.51cto.com/2683824/1885184

Shell script Execution Conflict event-ssh&while