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AWK: is there any flag to ignore comments?

Comment lines are counted in NR.

  • Is there any flag to ignore comments?
  • How can you limit the range in AWK rather than piping | sed -e '1d'to ignore comment lines?

Example

$ awk '{sum+=$3} END {avg=sum/NR} END {print avg}' coriolis_data
0.885491                          // WRONG divided by 11, should be by 10
$ cat coriolis_data 
#d-err-t-err-d2-err
.105    0.005   0.9766  0.0001  0.595   0.005
.095    0.005   0.9963  0.0001  0.595   0.005
.115    0.005   0.9687  0.0001  0.595   0.005
.105    0.005   0.9693  0.0001  0.595   0.005
.095    0.005   0.9798  0.0001  0.595   0.005
.105    0.005   0.9798  0.0001  0.595   0.005
.095    0.005   0.9711  0.0001  0.595   0.005
.110    0.005   0.9640  0.0001  0.595   0.005
.105    0.005   0.9704  0.0001  0.595   0.005
.090    0.005   0.9644  0.0001  0.595   0.005
+5
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6 answers

Just reduce the NR yourself on the comment lines:

 awk '/^[[:space:]]*#/ { NR-- } {sum+=$3} END { ... }' coriolis_data

Ok, this is the answer to the question you asked, but the question you really had in mind:

 awk '{ if ($0 ~ /^[[:space:]]*#/) {NR--} else {sum+=$3} END { ... }' coriolis_data

(This is more awk-ish for using templates outside of blocks, as in the first answer, but for this you will have to write a comment template twice.)

: /.../ {NR--; next}, if-else. , , , - . !

+6

NR, . , .

$ awk '!/^[ \t]*#/&&NF{sum+=$3;++d}END{ave=sum/d;print ave}' file
0.97404
+6

...

awk '{ if( $1 != "#" ){ print $0 } }' coriolis_data

, awk , #. , # .

+3

, AWK, , data​​strong > , AWK . , AWK , #, .

, , : AWK , "#", .

awk 'BEGIN {lines=0} {if(substr($1, 0, 1) != "#") {sum+=$3; lines++} } END {avg=sum/lines} END {print avg}' coriolis_data

, , .

+2

sed, grep.

sed 's/#.*//' < coriolis_data | egrep -v '^$' | awk ...

0

!

$ awk '!/#/ {print $0}' coriolis_data
.105 0.005 0.9766 0.0001 0.595 0.005
.095 0.005 0.9963 0.0001 0.595 0.005
.115 0.005 0.9687 0.0001 0.595 0.005
.105 0.005 0.9693 0.0001 0.595 0.005
.095 0.005 0.9798 0.0001 0.595 0.005
.105 0.005 0.9798 0.0001 0.595 0.005
.095 0.005 0.9711 0.0001 0.595 0.005
.110 0.005 0.9640 0.0001 0.595 0.005
.105 0.005 0.9704 0.0001 0.595 0.005
.090 0.005 0.9644 0.0001 0.595 0.005

: , !

$ awk '!/#/ {sum+=$3}END{ave=sum/NR}END{print ave}' coriolis_data 
0.885491    // WRONG.
$ awk '{if ($0 ~ /^[[:space:]]*#/){NR--}else{sum+=$3}}END{ave=sum/NR}END{print ave}' coriolis_data
0.97404     // RIGHT.
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