I am working on a UNIX box, and trying to run an application, which gives some debug logs to the standard output. I have redirected this output to a log file, but now wish to get the lines where the error is being shown.
My problem here is that a simple
cat output.log | grep FAIL
does not help out. As this shows only the lines which have FAIL in them. I want some more information along with this. Like the 2-3 lines above this line with FAIL. Is there any way to do this via a simple shell command? I would like to have a single command line (can have pipes) to do the above.
grep -C 3 FAIL output.log
Note that this also gets rid of the useless use of cat (UUOC).
grep -A $NUM
This will print $NUM lines of trailing context after matches.
-B $NUM prints leading context.
man grep is your best friend.
So in your case:
cat log | grep -A 3 -B 3 FAIL
I have two implementations of what I call sgrep, one in Perl, one using just pre-Perl (pre-GNU) standard Unix commands. If you've got GNU grep, you've no particular need of these. It would be more complex to deal with forwards and backwards context searches, but that might be a useful exercise.
Perl solution:
#!/usr/perl/v5.8.8/bin/perl -w
#
# #(#)$Id: sgrep.pl,v 1.6 2007/09/18 22:55:20 jleffler Exp $
#
# Perl-based SGREP (special grep) command
#
# Print lines around the line that matches (by default, 3 before and 3 after).
# By default, include file names if more than one file to search.
#
# Options:
# -b n1 Print n1 lines before match
# -f n2 Print n2 lines following match
# -n Print line numbers
# -h Do not print file names
# -H Do print file names
use strict;
use constant debug => 0;
use Getopt::Std;
my(%opts);
sub usage
{
print STDERR "Usage: $0 [-hnH] [-b n1] [-f n2] pattern [file ...]\n";
exit 1;
}
usage unless getopts('hnf:b:H', \%opts);
usage unless #ARGV >= 1;
if ($opts{h} && $opts{H})
{
print STDERR "$0: mutually exclusive options -h and -H specified\n";
exit 1;
}
my $op = shift;
print "# regex = $op\n" if debug;
# print file names if -h omitted and more than one argument
$opts{F} = (defined $opts{H} || (!defined $opts{h} and scalar #ARGV > 1)) ? 1 : 0;
$opts{n} = 0 unless defined $opts{n};
my $before = (defined $opts{b}) ? $opts{b} + 0 : 3;
my $after = (defined $opts{f}) ? $opts{f} + 0 : 3;
print "# before = $before; after = $after\n" if debug;
my #lines = (); # Accumulated lines
my $tail = 0; # Line number of last line in list
my $tbp_1 = 0; # First line to be printed
my $tbp_2 = 0; # Last line to be printed
# Print lines from #lines in the range $tbp_1 .. $tbp_2,
# leaving $leave lines in the array for future use.
sub print_leaving
{
my ($leave) = #_;
while (scalar(#lines) > $leave)
{
my $line = shift #lines;
my $curr = $tail - scalar(#lines);
if ($tbp_1 <= $curr && $curr <= $tbp_2)
{
print "$ARGV:" if $opts{F};
print "$curr:" if $opts{n};
print $line;
}
}
}
# General logic:
# Accumulate each line at end of #lines.
# ** If current line matches, record range that needs printing
# ** When the line array contains enough lines, pop line off front and,
# if it needs printing, print it.
# At end of file, empty line array, printing requisite accumulated lines.
while (<>)
{
# Add this line to the accumulated lines
push #lines, $_;
$tail = $.;
printf "# array: N = %d, last = $tail: %s", scalar(#lines), $_ if debug > 1;
if (m/$op/o)
{
# This line matches - set range to be printed
my $lo = $. - $before;
$tbp_1 = $lo if ($lo > $tbp_2);
$tbp_2 = $. + $after;
print "# $. MATCH: print range $tbp_1 .. $tbp_2\n" if debug;
}
# Print out any accumulated lines that need printing
# Leave $before lines in array.
print_leaving($before);
}
continue
{
if (eof)
{
# Print out any accumulated lines that need printing
print_leaving(0);
# Reset for next file
close ARGV;
$tbp_1 = 0;
$tbp_2 = 0;
$tail = 0;
#lines = ();
}
}
Pre-Perl Unix solution (using plain ed, sed, and sort - though it uses getopt which was not necessarily available back then):
#!/bin/ksh
#
# #(#)$Id: old.sgrep.sh,v 1.5 2007/09/15 22:15:43 jleffler Exp $
#
# Special grep
# Finds a pattern and prints lines either side of the pattern
# Line numbers are always produced by ed (substitute for grep),
# which allows us to eliminate duplicate lines cleanly. If the
# user did not ask for numbers, these are then stripped out.
#
# BUG: if the pattern occurs in in the first line or two and
# the number of lines to go back is larger than the line number,
# it fails dismally.
set -- `getopt "f:b:hn" "$#"`
case $# in
0) echo "Usage: $0 [-hn] [-f x] [-b y] pattern [files]" >&2
exit 1;;
esac
# Tab required - at least with sed (perl would be different)
# But then the whole problem would be different if implemented in Perl.
number="'s/^\\([0-9][0-9]*\\) /\\1:/'"
filename="'s%^%%'" # No-op for sed
f=3
b=3
nflag=no
hflag=no
while [ $# -gt 0 ]
do
case $1 in
-f) f=$2; shift 2;;
-b) b=$2; shift 2;;
-n) nflag=yes; shift;;
-h) hflag=yes; shift;;
--) shift; break;;
*) echo "Unknown option $1" >&2
exit 1;;
esac
done
pattern="${1:?'No pattern'}"
shift
case $# in
0) tmp=${TMPDIR:-/tmp}/`basename $0`.$$
trap "rm -f $tmp ; exit 1" 0
cat - >$tmp
set -- $tmp
sort="sort -t: -u +0n -1"
;;
*) filename="'s%^%'\$file:%"
sort="sort -t: -u +1n -2"
;;
esac
case $nflag in
yes) num_remove='s/[0-9][0-9]*://';;
no) num_remove='s/^//';;
esac
case $hflag in
yes) fileremove='s%^$file:%%';;
no) fileremove='s/^//';;
esac
for file in $*
do
echo "g/$pattern/.-${b},.+${f}n" |
ed - $file |
eval sed -e "$number" -e "$filename" |
$sort |
eval sed -e "$fileremove" -e "$num_remove"
done
rm -f $tmp
trap 0
exit 0
The shell version of sgrep was written in February 1989, and bug fixed in May 1989. It then remained unchanged except for an administrative change (SCCS to RCS transition) in 1997 until 2007, when I added the -h option. I switched to the Perl version in 2007.
http://thedailywtf.com/Articles/The_Complicator_0x27_s_Gloves.aspx
You can use sed to print specific lines, lets say you want line 20
sed '20 p' -n FILE_YOU_WANT_THE_LINE_FROM
Done.
-n prevents echoing lines from the file. The part in quotes is a sed rule to apply, it specifies that you want the rule to apply to line 20, and you want to print.
With GNU grep on Windows:
$ grep --context 3 FAIL output.log
$ grep --help | grep context
-B, --before-context=NUM print NUM lines of leading context
-A, --after-context=NUM print NUM lines of trailing context
-C, --context=NUM print NUM lines of output context
-NUM same as --context=NUM
Related
I'm trying to extract all (only) the duplicate values from a pipe delimited file.
My data file has 800 thousands rows with multiple columns and I'm particularly interested about column 3. So I need to get the duplicate values of column 3 and extract all the duplicate rows from that file.
I'm, however able to achieve this as shown below..
cat Report.txt | awk -F'|' '{print $3}' | sort | uniq -d >dup.txt
and I take the above in loop as shown below..
while read dup
do
grep "$dup" Report.txt >>only_dup.txt
done <dup.txt
I've also tried the awk method
while read dup
do
awk -v a=$dup '$3 == a { print $0 }' Report.txt>>only_dup.txt
done <dup.txt
But, as I have large number of records in the file, it's taking ages to complete. So I'm looking for an easy and quick alternative.
For example, I have data like this:
1|learning|Unix|Business|Requirements
2|learning|Unix|Business|Team
3|learning|Linux|Business|Requirements
4|learning|Unix|Business|Team
5|learning|Linux|Business|Requirements
6|learning|Unix|Business|Team
7|learning|Windows|Business|Requirements
8|learning|Mac|Business|Requirements
And my expected output which doesn't include unique records:
1|learning|Unix|Business|Requirements
2|learning|Unix|Business|Team
4|learning|Unix|Business|Team
6|learning|Unix|Business|Team
3|learning|Linux|Business|Requirements
5|learning|Linux|Business|Requirements
This may be what you want:
$ awk -F'|' 'NR==FNR{cnt[$3]++; next} cnt[$3]>1' file file
1|learning|Unix|Business|Requirements
2|learning|Unix|Business|Team
3|learning|Linux|Business|Requirements
4|learning|Unix|Business|Team
5|learning|Linux|Business|Requirements
6|learning|Unix|Business|Team
or if the file's too large for all the keys ($3 values) to fit in memory (which shouldn't be a problem with just the unique $3 values from 800,000 lines):
$ cat tst.awk
BEGIN { FS="|" }
{ currKey = $3 }
currKey == prevKey {
if ( !prevPrinted++ ) {
print prevRec
}
print
next
}
{
prevKey = currKey
prevRec = $0
prevPrinted = 0
}
$ sort -t'|' -k3,3 file | awk -f tst.awk
3|learning|Linux|Business|Requirements
5|learning|Linux|Business|Requirements
1|learning|Unix|Business|Requirements
2|learning|Unix|Business|Team
4|learning|Unix|Business|Team
6|learning|Unix|Business|Team
EDIT2: As per Ed sir's suggestion fine tuned my suggestion with more meaningful names(IMO) of arrays.
awk '
match($0,/[^\|]*\|/){
val=substr($0,RSTART+RLENGTH)
if(!unique_check_count[val]++){
numbered_indexed_array[++count]=val
}
actual_valued_array[val]=(actual_valued_array[val]?actual_valued_array[val] ORS:"")$0
line_count_array[val]++
}
END{
for(i=1;i<=count;i++){
if(line_count_array[numbered_indexed_array[i]]>1){
print actual_valued_array[numbered_indexed_array[i]]
}
}
}
' Input_file
Edit by Ed Morton: FWIW here's how I'd have named the variables in the above code:
awk '
match($0,/[^\|]*\|/) {
key = substr($0,RSTART+RLENGTH)
if ( !numRecs[key]++ ) {
keys[++numKeys] = key
}
key2recs[key] = (key in key2recs ? key2recs[key] ORS : "") $0
}
END {
for ( keyNr=1; keyNr<=numKeys; keyNr++ ) {
key = keys[keyNr]
if ( numRecs[key]>1 ) {
print key2recs[key]
}
}
}
' Input_file
EDIT: Since OP changed Input_file with |delimited so changing code a bit to as follows, which deals with new Input_file(Thanks to Ed Morton sir for pointing it out).
awk '
match($0,/[^\|]*\|/){
val=substr($0,RSTART+RLENGTH)
if(!a[val]++){
b[++count]=val
}
c[val]=(c[val]?c[val] ORS:"")$0
d[val]++
}
END{
for(i=1;i<=count;i++){
if(d[b[i]]>1){
print c[b[i]]
}
}
}
' Input_file
Could you please try following, following will give output in same sequence of in which lines are occurring in Input_file.
awk '
match($0,/[^ ]* /){
val=substr($0,RSTART+RLENGTH)
if(!a[val]++){
b[++count]=val
}
c[val]=(c[val]?c[val] ORS:"")$0
d[val]++
}
END{
for(i=1;i<=count;i++){
if(d[b[i]]>1){
print c[b[i]]
}
}
}
' Input_file
Output will be as follows.
2 learning Unix Business Team
4 learning Unix Business Team
6 learning Unix Business Team
3 learning Linux Business Requirements
5 learning Linux Business Requirements
Explanation for above code:
awk ' ##Starting awk program here.
match($0,/[^ ]* /){ ##Using match function of awk which matches regex till first space is coming.
val=substr($0,RSTART+RLENGTH) ##Creating variable val whose value is sub-string is from starting point of RSTART+RLENGTH value to till end of line.
if(!a[val]++){ ##Checking condition if value of array a with index val is NULL then go further and increase its index too.
b[++count]=val ##Creating array b whose index is increment value of variable count and value is val variable.
} ##Closing BLOCK for if condition of array a here.
c[val]=(c[val]?c[val] ORS:"")$0 ##Creating array named c whose index is variable val and value is $0 along with keep concatenating its own value each time it comes here.
d[val]++ ##Creating array named d whose index is variable val and its value is keep increasing with 1 each time cursor comes here.
} ##Closing BLOCK for match here.
END{ ##Starting END BLOCK section for this awk program here.
for(i=1;i<=count;i++){ ##Starting for loop from i=1 to till value of count here.
if(d[b[i]]>1){ ##Checking if value of array d with index b[i] is greater than 1 then go inside block.
print c[b[i]] ##Printing value of array c whose index is b[i].
}
}
}
' Input_file ##Mentioning Input_file name here.
Another in awk:
$ awk -F\| '{ # set delimiter
n=$1 # store number
sub(/^[^|]*/,"",$0) # remove number from string
if($0 in a) { # if $0 in a
if(a[$0]==1) # if $0 seen the second time
print b[$0] $0 # print first instance
print n $0 # also print current
}
a[$0]++ # increase match count for $0
b[$0]=n # number stored to b and only needed once
}' file
Output for the sample data:
2|learning|Unix|Business|Team
4|learning|Unix|Business|Team
3|learning|Linux|Business|Requirements
5|learning|Linux|Business|Requirements
6|learning|Unix|Business|Team
Also, would this work:
$ sort -k 2 file | uniq -D -f 1
or -k2,5 or smth. Nope, as the delimiter changed from space to pipe.
Two steps of improvement.
First step:
After
awk -F'|' '{print $3}' Report.txt | sort | uniq -d >dup.txt
# or
cut -d "|" -f3 < Report.txt | sort | uniq -d >dup.txt
you can use
grep -f <(sed 's/.*/^.*|.*|&|.*|/' dup.txt) Report.txt
# or without process substitution
sed 's/.*/^.*|.*|&|.*|/' dup.txt > dup.sed
grep -f dup.sed Report.txt
Second step:
Use awk as given in other, better, answers.
I have a scenario wherein I want to have 9 character count in expr.
I have sample code which is:
var1=012345678 #this is 9 characters
sum=`expr $var1 + 1`
echo "$sum"
Here is the result:
./sample.sh : 12345679 #this is only 8 characters
My expected output:
./sample.sh : 012345679
Any help on this?
The leading zero is removed when doing the math.
You can force a 9 length output using printf "%09d" 123.
When you try to use the the syntax ((sum=${var1} + 1 )) you have another problem: When the first digit is 0, bash expects a different radix.
You can remove the first 0 with
var1=012345678
echo "${var1#0}"
This only helps with your input, not with 00012.
Removing the leading zeroes and printing the sum can be done with echo $((10#$var1))
var1=00012345678
((sum=$((10#$var1)) + 1))
printf "%09d\n" $sum
This can be solved easier with
var1=00012345678
echo "${var1} 1" |awk '{ printf("%09d\n", $1 + $2) }'
You can avoid the echo with
awk -v var1=$var1 'BEGIN { printf("%09d\n", var1 + 1) }'
The BEGIN is used for parsing without an inputfile.
The option -v is a clean way to use a shell variable inside an awk script.
Do not try things with quotes, one day it will shoot your own foot:
# Don't do this
awk 'BEGIN { printf("%09d\n", '${var1}' + 1) }' # Just do not do it
My main question is how to split strings on the command line into parameters using a terminal command in Linux?
For example
on the command line:
./my program hello world "10 20 30"
The parameters are set as:
$1 = hello
$2 = world
$3 = 10 20 30
But I want:
$1 = hello
$2 = world
$3 = 10
$4 = 20
$5 = 30
How can I do it correctly?
You can reset the positional parameters $# by using the set builtin. If you do not double-quote $#, the shell will word-split it producing the behavior you desire:
$ cat my_program.sh
#! /bin/sh
i=1
for PARAM; do
echo "$i = $PARAM";
i=$(( $i + 1 ));
done
set -- $#
echo "Reset \$# with word-split params"
i=1
for PARAM; do
echo "$i = $PARAM";
i=$(( $i + 1 ));
done
$ sh ./my_program.sh foo bar "baz buz"
1 = foo
2 = bar
3 = baz buz
Reset $# with word-split params
1 = foo
2 = bar
3 = baz
4 = buz
As an aside, I find it mildly surprising that you want to do this. Many shell programmers are frustrated by the shell's easy, accidental word-splitting — they get "John", "Smith" when they wanted to preserve "John Smith" — but it seems to be your requirement here.
Use xargs:
echo "10 20 30" | xargs ./my_program hello world
xargs is a command on Unix and most Unix-like operating systems used
to build and execute command lines from standard input. Commands such as
grep and awk can accept the standard input as a parameter, or argument
by using a pipe. However, others such as cp and echo disregard the
standard input stream and rely solely on the arguments found after the
command. Additionally, under the Linux kernel before version 2.6.23,
and under many other Unix-like systems, arbitrarily long lists of
parameters cannot be passed to a command,[1] so xargs breaks the list
of arguments into sublists small enough to be acceptable.
(source)
I am trying to split a file into different smaller files depending on the value of the fifth field. A very nice way to do this was already suggested and also here.
However, I am trying to incorporate this into a .sh script for qsub, without much success.
The problem is that in the section where the file to which output the line is specified,
i.e., f = "Alignments_" $5 ".sam" print > f
, I need to pass a variable declared earlier in the script, which specifies the directory where the file should be written. I need to do this with a variable which is built for each task when I send out the array job for multiple files.
So say $output_path = ./Sample1
I need to write something like
f = $output_path "/Alignments_" $5 ".sam" print > f
But it does not seem to like having a $variable that is not a $field belonging to awk. I don't even think it likes having two "strings" before and after the $5.
The error I get back is that it takes the first line of the file to be split (little.sam) and tries to name f like that, followed by /Alignments_" $5 ".sam" (those last three put together correctly). It says, naturally, that it is too big a name.
How can I write this so it works?
Thanks!
awk -F '[:\t]' ' # read the list of numbers in Tile_Number_List
FNR == NR {
num[$1]
next
}
# process each line of the .BAM file
# any lines with an "unknown" $5 will be ignored
$5 in num {
f = "Alignments_" $5 ".sam" print > f
} ' Tile_Number_List.txt little.sam
UPDATE, AFTER ADDING -V TO AWK AND DECLARING THE VARIABLE OPATH
input=$1
outputBase=${input%.bam}
mkdir -v $outputBase\_TEST
newdir=$outputBase\_TEST
samtools view -h $input | awk 'NR >= 18' | awk -F '[\t:]' -v opath="$newdir" '
FNR == NR {
num[$1]
next
}
$5 in num {
f = newdir"/Alignments_"$5".sam";
print > f
} ' Tile_Number_List.txt -
mkdir: created directory little_TEST'
awk: cmd. line:10: (FILENAME=- FNR=1) fatal: can't redirect to `/Alignments_1101.sam' (Permission denied)
awk variables are like C variables - just reference them by name to get their value, no need to stick a "$" in front of them like you do with shell variables:
awk -F '[:\t]' ' # read the list of numbers in Tile_Number_List
FNR == NR {
num[$1]
next
}
# process each line of the .BAM file
# any lines with an "unknown" $5 will be ignored
$5 in num {
output_path = "./Sample1/"
f = output_path "Alignments_" $5 ".sam"
print > f
} ' Tile_Number_List.txt little.sam
To pass the value of the shell variable such as $output_path to awk you need to use the -v option.
$ output_path=./Sample1/
$ awk -F '[:\t]' -v opath="$ouput_path" '
# read the list of numbers in Tile_Number_List
FNR == NR {
num[$1]
next
}
# process each line of the .BAM file
# any lines with an "unknown" $5 will be ignored
$5 in num {
f = opath"Alignments_"$5".sam"
print > f
} ' Tile_Number_List.txt little.sam
Also you still have the error from your previous question left in your script
EDIT:
The awk variable created with -v is obase but you use newdir what you want is:
input=$1
outputBase=${input%.bam}
mkdir -v $outputBase\_TEST
newdir=$outputBase\_TEST
samtools view -h "$input" | awk -F '[\t:]' -v opath="$newdir" '
FNR == NR && NR >= 18 {
num[$1]
next
}
$5 in num {
f = opath"/Alignments_"$5".sam" # <-- opath is the awk variable not newdir
print > f
}' Tile_Number_List.txt -
You should also move NR >= 18 into the second awk script.
Usually grep command is used to display the line contaning the specified pattern. Is there any way to display n lines before and after the line which contains the specified pattern?
Can this will be achieved using awk?
Yes, use
grep -B num1 -A num2
to include num1 lines of context before the match, and num2 lines of context after the match.
EDIT:
Seems the OP is using AIX. This has a different set of options which doesn't include -B and -A
this link describes grep on AIX 4.3 (it doesn't look promising)
Matt's perl script might be a better solution.
Here is what I usually do on AIX:
before=2 << The number of lines to be shown Before >>
after=2 << The number of lines to be shown After >>
grep -n <pattern> <filename> | cut -d':' -f1 | xargs -n1 -I % awk "NR<=%+$after && NR>=%-$before" <filename>
If you do not want the extra 2 varialbles you can always use it an a one line:
grep -n <pattern> <filename> | cut -d':' -f1 | xargs -n1 -I % awk 'NR<=%+<<after>> && NR>=%-<<before>>' <filename>
Suppose I have a pattern 'stack' and the filename is flow.txt
I want 2 lines before and 3 lines after. The the command will be like:
grep -n 'stack' flow.txt | cut -d':' -f1 | xargs -n1 -I % awk 'NR<=%+3 && NR>=%-2' flow.txt
I want 2 lines before and only - the the command will be like:
grep -n 'stack' flow.txt | cut -d':' -f1 | xargs -n1 -I % awk 'NR<=% && NR>=%-2' flow.txt
I want 3 lines after and only - the the command will be like:
grep -n 'stack' flow.txt | cut -d':' -f1 | xargs -n1 -I % awk 'NR<=%+3 && NR>=%' flow.txt
Multiple Files - change it for Awk & grep. From above for the pattern 'stack' with the filename is flow.* - 2 lines before and 3 lines after. The the command will be like:
awk 'BEGIN {
before=1; after=3; pattern="stack";
i=0; hold[before]=""; afterprints=0}
{
#Print the lines from the previous Match
if (afterprints > 0)
{
print FILENAME ":" FNR ":" $0
afterprints-- #keep a track of the lines to print after - this can be reset if a match is found
if (afterprints == 0) print "---"
}
#Look for the pattern in current line
if ( match($0, pattern) > 0 )
{
# print the lines in the hold round robin buffer from the current line to line-1
# if (before >0) => user wants lines before avoid divide by 0 in %
# and afterprints => 0 - we have not printed the line already
for(j=i; j < i+before && before > 0 && afterprints == 0 ; j++)
print hold[j%before]
if (afterprints == 0) # print the line if we have not printed the line already
print FILENAME ":" FNR ":" $0
afterprints=after
}
if (before > 0) # Store the lines in the round robin hold buffer
{ hold[i]=FILENAME ":" FNR ":" $0
i=(i+1)%before }
}' flow.*
From the tags, it's likely that the system has a grep that may not support providing context (Solaris is one system that doesn't and I can't remember about AIX). If that is the case, there's a perl script that may help at http://www.sun.com/bigadmin/jsp/descFile.jsp?url=descAll/cgrep__context_grep.
If you have sed you could use this shell script
BEFORE=2
AFTER=3
FILE=file.txt
PATTERN=pattern
for i in $(grep -n $PATTERN $FILE | sed -e 's/\:.*//')
do head -n $(($AFTER+$i)) $FILE | tail -n $(($AFTER+$BEFORE+1))
done
What it does is, grep -n prefixes each match with the line it was found at, the sed strips all but the line it was found at. Then you use head to get the lines up to the line it was found on plus an additional $AFTER lines. That's then piped to tail to just get $BEFORE + $AFTER + 1 lines (that is, your matching line plus the number of lines before and after)
Sure there is (from the grep man page):
-B NUM, --before-context=NUM
Print NUM lines of leading context before matching lines.
Places a line containing a group separator (--) between
contiguous groups of matches. With the -o or --only-matching
option, this has no effect and a warning is given.
-A NUM, --after-context=NUM
Print NUM lines of trailing context after matching lines.
Places a line containing a group separator (--) between
contiguous groups of matches. With the -o or --only-matching
option, this has no effect and a warning is given.
and if you want the same amount of lines before AND after the match, use:
-C NUM, -NUM, --context=NUM
Print NUM lines of output context. Places a line containing a
group separator (--) between contiguous groups of matches. With
the -o or --only-matching option, this has no effect and a
warning is given.
you can use awk
awk 'BEGIN{t=4}
c--&&c>=0
/pattern/{ c=t; for(i=NR;i<NR+t;i++)print a[i%t] }
{ a[NR%t]=$0}
' file
output
$ more file
1
2
3
4
5
pattern
6
7
8
9
10
11
$ ./shell.sh
2
3
4
5
6
7
8
9