如何在新行上获取diff命令的输出

Question

I'm new to the world of scripting and and currently using a script to perform a health check on the san devices that I manage.

The script is simple and redirects output of commands to a current file from remote device to my local host. I then use a diff command to compare output of current file and reference file and get a email alert of the difference. The output of diff is passed to a variable "variable" and then using a if loop if get the result

I have so far got the autologin and email part working ( i get a email only if there is a difference from DIFF command). However the email that i now get has its test concatenated into one long string, which is bad for viewing and not easy to understand for the people who will be getting it.

My current script is pasted below

ssh test@ip_of_device switchshow > switchshow_results
variable=diff switchshow_reference switchshow_results
if [[ $variable -eq 0 ]]
then
    echo $"nothing"
else
    echo $variable | mail -s switch_HARDWARE_CHECK recipeint_email_address
fi

The output of the above script is blank and i do not get any email when the diff command does not find any difference.

However when the diff commands finds a difference, i get a email as pasted below

16c16 < 0 0 010000 id N4 Online FC F-Port 1 N Port + 1 NPIV public --- > 0 0 010000 id N4 No_Light FC F-Port 1 N Port + 1 NPIV public 26c26 < 10 10 010a00 id N4 Online FC F-Port 1     N Port + 1 NPIV public --- > 10 10 010a00 id N4 No_Light FC F-Port 1 N Port + 1 NPIV public 29c29 < 13 13 010d00 id N4 Online FC F-Port 50:06:01:67:3b:20:23:0a --- > 13 13 010d00 id N4 No_Light FC F-Port 50:06:01:67:3b:20:23:0a

This should ideally look like this in the email..

16c16 < 0 0 010000 id N4 Online FC F-Port 1 N Port + 1 NPIV public --- > 0 0 010000 id N4 No_Light FC F-Port 1 N Port + 1 NPIV public

26c26 < 10 10 010a00 id N4 Online FC F-Port 1 N Port + 1 NPIV public --- > 10 10 010a00 id N4 No_Light FC F-Port 1 N Port + 1 NPIV public

29c29 < 13 13 010d00 id N4 Online FC F-Port 50:06:01:67:3b:20:23:0a --- > 13 13 010d00 id N4 No_Light FC F-Port 50:06:01:67:3b:20:23:0a

output should display one line at a time in the email. Any suggestions? This works fine when there is only one line which has the difference, however multiple line difference gives me the above issue. Also my requirement is that diff output has to be emailed to me. I checked the various options in diff command, however i was not able to figure out any that would help me.

Any help would be much appriciated.

Answer 1

You need to run a sed command to replace '/n' with '' in the email conteent that is being sent.

Emails are rendered as HTML text, hence the /n is ommited.
makes the html show it on next line.

Answer 2

You forgot to place quotes around $variable

Use this:

echo "$variable" | mail -s switch_HARDWARE_CHECK recipeint_email_address

The reason for that is explained here

Answer 3

What's supposed to be in "variable"?

the output of the diff? (use backticks)

or diff's exit code? (use $?)

Because what you've got right now gives me an error.

-bash: switchshow_reference: command not found