Cut works with echo but not without it

Question

So I am trying to extract an output similar to

x=($discover nginx --human=nood)

which gives me an output like

i-03099 nginx IP noodlefish pip b4b966d280546c6b070f5f952c281d3294308048

Further I want to extract the pip column in another variable. When I do

echo "$x" | cut -f6

I get my desired output, but when I try.

y= "$x" | cut -f6

I get a blank output.

Please can you explain me why is this happening and how can I get the result I want. Thank you in advance.

y="$x" doesn't produce any output, so there's nothing to cut. — ajgringo619, Nov 25 '19 at 16:28
Is the output of the command in $discover tab delimited? Why don't you pass it through cut immediately? x=("$discover" nginx --human=nood | cut -f 6) or x=$("$discover" nginx --human=nood | awk '{ print $NF }') — Kusalananda, Nov 25 '19 at 16:29

score 1 · Answer 1 · answered Nov 25 '19 at 16:52

Further I want to extract the pip column in another variable. When I do

echo "$x" | cut -f6

I get my desired output[...]

That's weird, because this should not work, since

‘-f FIELD-LIST’
‘--fields=FIELD-LIST’
     Select for printing only the fields listed in FIELD-LIST.  Fields
     are separated by a TAB character by default.  Also print any line
     that contains no delimiter character, unless the ‘--only-delimited’
     (‘-s’) option is specified.

-f should work only when fields are separated by TAB, unless -d sets it otherwise.

If you want to extract the field after the word pip, such script works for me

x="i-03099 nginx IP noodlefish pip b4b966d280546c6b070f5f952c281d3294308048"

y=$(echo -n "$x" | cut -d ' ' -f 6 -)

echo "$y"

I think it is already tab separated. Thank you for pointing that out. — Shivangi Singh, Nov 25 '19 at 16:57

score -1 · Answer 2 · answered Nov 25 '19 at 16:28

-1

Use below command

y=`echo $x |cut -f6`

answered Nov 25 '19 at 16:28

Praveen Kumar BS

5,211

1

Backtics are not a modern practice: https://unix.stackexchange.com/questions/204949/when-should-one-use-in-defining-variables/204952#204952 – Christopher Nov 25 '19 at 16:29
1

and variables should be quoted... – Jeff Schaller Nov 25 '19 at 16:32
I didnt know that was a back tick. Thank you – Shivangi Singh Nov 25 '19 at 16:34

Cut works with echo but not without it

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