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Delete line from text file with line numbers from another file

I have a text file containing a giant list of line numbers that I have to remove from another main file. Here my data looks like

lines.txt

1
2
4
5
22
36
400
...

and documents.txt

string1
string2
string3
...

If I had a short list of line numbers, I could easily use

sed -i '1d,4d,5d' documents.txt.

But there are many line numbers that I have to delete. Alternatively, I could use a bash / perl script to store line numbers in an array and echo lines that are not in the array. But I was wondering if there is a built-in command to do just that.

Any help would be greatly appreciated.

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5 answers

awk oneliner should work for you, see test below:

kent$  head lines.txt doc.txt 
==> lines.txt <==
1
3
5
7

==> doc.txt <==
a
b
c
d
e
f
g
h

kent$  awk 'NR==FNR{l[$0];next;} !(FNR in l)' lines.txt doc.txt
b
d
f
h

, :

awk                     # the awk command
 'NR==FNR{l[$0];next;}  # process the first file(lines.txt),save each line(the line# you want to delete) into an array "l"

 !(FNR in l)'           #now come to the 2nd file(doc.txt), if line number not in "l",print the line out
 lines.txt              # 1st argument, file:lines.txt
 docs.txt               # 2nd argument, file:doc.txt
+9

, Perl bash . , Rexx :

lines_to_delete = ""

do while lines( "lines.txt" )
   lines_to_delete = lines_to_delete linein( "lines.txt" )
end

n = 0
do while lines( "documents.txt" )
   line = linein( "documents.txt" )
   n = n + 1
   if ( wordpos( n, lines_to_delete ) == 0 )
      call lineout "temp_out,txt", line
end

temp_out.txt, document.txt .

+2

sed:

sed ':a;${s/\n//g;s/^/sed \o47/;s/$/d\o47 documents.txt/;b};s/$/d\;/;N;ba' lines.txt | sh

sed sed , . sed `sed '3d; 5d; 11d' documents.txt.

sed d; , , (N; ba). ($), , sed ' d ' documents.txt. b :a - ba , .

join cat -n ( , lines.txt):

join -t $'\v' -v 2 -o 2.2 lines.txt <(cat -n documents.txt | sed 's/^ *//;s/\t/\v/')

.txt :

join -t $'\v' -v 2 -o 2.2 <(sort lines.txt) <(cat -n documents.txt | sed '^s/ *//;s/\t/\v/')

Edit:

​​ join, document.txt.

+2

(GNU sed):

sed 's/.*/&d/' lines.txt | sed -i -f - documents.txt


sed ':a;$!{N;ba};s/\n/d;/g;s/^/sed -i '\''/;s/$/d'\'' documents.txt/' lines.txt | sh
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I asked a similar question on Unix SE and got great answers, including the following awk script:

#!/bin/bash
#
# filterline keeps a subset of lines of a file.
#
# cf. https://unix.stackexchange.com/q/209404/376
#
set -eu -o pipefail

if [ "$#" -ne 2 ]; then
    echo "Usage: filterline FILE1 FILE2"
    echo
    echo "FILE1: one integer per line indicating line number, one-based, sorted"
    echo "FILE2: input file to filter"
    exit 1
fi

LIST="$1" LC_ALL=C awk '
  function nextline() {
    if ((getline n < list) <=0) exit
  }
  BEGIN{
    list = ENVIRON["LIST"]
    nextline()
  }
  NR == n {
    print
    nextline()
  }' < "$2"

And another version of C that is slightly more efficient:

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