Using this script:
awk '{print $0"\t"NR}' test | grep NA | awk '{print $21}'
I get the line numbers in my file, having "NA" in them
326
399
672
1512
1734
1737
2212
Using sed, can I delete these lines from my file in the same command through standard input, by piping after the last awk command? If not, is there any way to do it in a simple way?
The simpler way is to use only sed:
sed '/NA/d' test >test.new
If you want to do in-place editing with GNU sed (this will modify the file test):
sed -i '/NA/d' test
The sed expression /NA/d will apply the d command on all lines in the input that matches the regular expression NA. The d command deletes lines.
If the line numbers were all you had, then the following would have worked too:
some_command | sed 's/$/d/' | sed -f /dev/stdin test >output
where some_command generates the line numbers that you'd like to delete from the file test.
The first sed turns the stream of numbers into a sed script by adding a d to each line. A line reading 100d would be interpreted as "delete line 100". This is then fed to the second sed as the actual script (it's reading the script via /dev/stdin) and it is applied to the file test.
The equivalent thing in a shell that knows about process substitutions:
sed -f <( some_command | sed 's/$/d/' ) test >output
But this is sillyness if you just want to delete lines containing the string NA.
Would it be too boring to just write this as one awk command?
awk '!/NA/' test
The default action is to print the whole line, so this is the same as !/NA/ { print $0 } and would print any line that doesn't contain NA.
testfile and the final resultgrep -v 'NA' testdoesn't solve your requirement...