Two commands, one pipeline

Question

I need these two commands to be one (so I can pipe them further):

dig +nottlid -t any bix.hu | egrep -v "^;;|^;|^$" | sort
dig +nottlid -t any www.bix.hu | egrep -v "^;;|^;|^$" | sort

I mean I need the output of these two commands to be in one pipe:

$ dig +nottlid -t any bix.hu | egrep -v "^;;|^;|^$" | sort
bix.hu.         IN  A   193.239.149.1
bix.hu.         IN  MX  10 deneb.iszt.hu.
bix.hu.         IN  NS  ns.iszt.hu.
bix.hu.         IN  NS  ns.iszt.hu.
bix.hu.         IN  NS  ns-s.nic.hu.
bix.hu.         IN  NS  ns-s.nic.hu.
bix.hu.         IN  SOA ns.iszt.hu. hostmaster.iszt.hu. 2011053000 28800 7200 604800 14400

and

dig +nottlid -t any www.bix.hu | egrep -v "^;;|^;|^$" | sort
bix.hu.         IN  NS  ns.iszt.hu.
bix.hu.         IN  NS  ns-s.nic.hu.
www.bix.hu.     IN  A   193.239.149.1

so that I could sha256sum them together, without writing the output of the two commands to one file, and sha256sum the file.

Q: it's like this:

echo hi | echo hi2 | sha256sum

of course this won't work, but are there any solutions for this? So that I need the sha256sum of:

hi
hi2
-->>
697ec886148d94d5b094df14f301f2e5a4abd8098a0e0dc2afb0a97945cea677

but I can only have the outputs from different commands [mentioned above, 2 different domains]. [Just want to write a "DNS checker" script to warn me when DNS records changes for a domain]

score 33 · Answer 1 · answered Oct 30 '11 at 17:15

33

A general solution is the following:

{ command1; command2; } | some-other-command

answered Oct 30 '11 at 17:15

enzotib

51,661

Or ( command1; command2; ) | some-other-command. – hlovdal Oct 31 '11 at 06:57
4

@hlovdal: yes, but in such a case you are running a subshell (someone would prefer to know), and the second ; is not required. – enzotib Oct 31 '11 at 07:56

score 14 · Accepted Answer · answered Oct 30 '11 at 17:01

14

You can pass multiple names to dig:

dig +nottlid -t any bix.hu www.bix.hu | egrep -v "^;;|^;|^$" | sort

answered Oct 30 '11 at 17:01

Mat

52,586

score 0 · Answer 3 · answered May 06 '12 at 01:20

There's two ways to get exactly that output without grepping:

Turn off the sections you don't want:

dig +nottlid +nocomments +noquestion +nostats +nocmd -t any bix.hu

Turn off all the sections then turn on the sections you do want:

dig +nottlid +noall +authority +answer +additional -t any bix.hu

Also, it seems the output gives a different additional (or "glue") section each time, so you might want to use +noadditional if you're just trying to check for changes to the zone file.

Two commands, one pipeline

3 Answers3

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