Printing the last column of a line in a file

Question

I have a file that is constantly being written to updated  I want to find the last line containing a particular word  then print the last column of that line   The file looks something like this  More A1 B1 C1 lines will be appended to it over time   A1 123 456 B1 234 567 C1 345 678 A1 098 766 B1 987 6545 C1 876 5434   I tried to use  tail -f file   grep A1   awk   print  NF     to print the value 766  but nothing is output   Is there a way to do this

User · Answer

awk -F        1   A1    print  NF   FILE   tail -n 1  Use awk with field separator -F set to a space        Use the pattern  1   A1  and action  print  NF   this will print the last field in every record where the first field is  A1   Pipe the result into tail and use the -n 1 option to only show the last line

User · Answer

You don t see anything  because of buffering  The output is shown  when there are enough lines or end of file is reached  tail -f means wait for more input  but there are no more lines in file and so the pipe to grep is never closed   If you omit -f from tail the output is shown immediately   tail file   grep A1   awk   print  NF        EdMorton is right of course  Awk can search for A1 as well  which shortens the command line to   tail file   awk   A1   print  NF     or without tail  showing the last column of all lines containing A1  awk   A1   print  NF   file     Thanks to  MitchellTracy s comment  tail might miss the record containing A1 and thus you get no output at all  This may be solved by switching tail and awk  searching first through the file and only then show the last line   awk   A1   print  NF   file   tail -n1

User · Answer

One way using awk   tail -f file txt   awk   A1    print  NF

User · Answer

Not the actual issue here  but might help some one  I was doing awk   print  NF    note the wrong quotes  Should be awk   print  NF    so that the shell doesn t expand  NF

User · Answer

Using Perl    cat rayne txt A1 123 456 B1 234 567 C1 345 678 A1 098 766 B1 987 6545 C1 876 5434     perl -lane    A1  and  x  F 2    END   print   x      rayne txt 766

User · Answer

To print the last column of a line just use   NF          awk   print   NF

User · Answer

maybe this works   grep A1 file   tail -1   awk   print  NF

User · Answer

You can do this without awk with just some pipes   tac file   grep -m1 A1   rev   cut -d    -f1   rev

User · Answer

ls -l   awk   print  9     tail -n1

User · Answer

You can do all of it in awk    lt file awk   1    A1   m  NF  END  print m

User · Answer

Execute this on the file   awk  ORS NR 3       n   filename   and you ll get what you re looking for

[file] Printing the last column of a line in a file

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