Can I grep only the first n lines of a file

Question

I have very long log files  is it possible to ask grep to only search the first 10 lines

User · Accepted Answer

The magic of pipes   head -10 log txt   grep  lt whatever gt

User · Answer

You can use the following line   head -n 10  path to file   grep

User · Answer

An extension to Joachim Isaksson s answer  Quite often I need something from the middle of a long file  e g  lines 5001 to 5020  in which case you can combine head with tail   head -5020 file txt   tail -20   grep x   This gets the first 5020 lines  then shows only the last 20 of those  then pipes everything to grep    Edited  fencepost error in my example numbers  added pipe to grep

User · Answer

head -10 log txt   grep -A 2 -B 2 pattern to search   -A 2  print two lines before the pattern     -B 2  print two lines after the pattern     head -10 log txt   read the first 10 lines of the file

User · Answer

grep -A 10  lt Pattern gt   This is to grab the pattern and the next 10 lines after the pattern  This would work well only for a known pattern  if you don t have a known pattern use the  head  suggestions

User · Answer

Or use awk for a single process without     awk   your regexp   amp  amp  NR  lt  11  INPUTFILE   On each line  if your regexp matches  and the number of records  lines  is less than 11  it executes the default action  which is printing the input line    Or use sed   sed -n   your regexp p 10q  INPUTFILE    Checks your regexp and prints the line  -n means don t print the input  which is otherwise the default   and quits right after the 10th line

User · Answer

You have a few options using programs along with grep  The simplest in my opinion is to use head   head -n10 filename   grep       head will output the first 10 lines  using the -n option   and then you can pipe that output to grep

User · Answer

grep  pattern   lt  head -n 10 filename

User · Answer

The output of head -10 file can be piped to grep in order to accomplish this   head -10 file   grep       Using Perl   perl -ne  last if     gt  10  print if  pattern   file

User · Answer

For folks who find this on Google  I needed to search the first n lines of multiple files  but to only print the matching filenames   I used   gawk  FNR gt 10  nextfile   pattern    print FILENAME   nextfile    filenames   The FNR  nextfile stops processing a file once 10 lines have been seen   The        prints the filename and moves on whenever the first match in a given file shows up   To quote the filenames for the benefit of other programs  use    gawk  FNR gt 10  nextfile   pattern    print      FILENAME        nextfile    filenames

User · Answer

grep -m6  string  cov txt   This searches only the first 6 lines for string

[bash] Can I grep only the first n lines of a file?

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