Using awk to pull specific lines from a file

by 
awk 'NR == FNR {nums[$1]; next} FNR in nums' numberfile datafile

simply referring to an array subscript creates the entry. Looping over the first file, while NR (record number) is equal to FNR (file record number) using the next statement stores all the line numbers in the array. After that when FNR of the second file is present in the array (true) the line is printed (which is the default action for “true”).

More Related Contents:

  1. How do you delete all lines that contain no letters from the alphabet using either grep, sed, or awk? [closed]
  2. substitute words on a line only before first delimeter using sed or awk
  3. Printing with sed or awk a line following a matching pattern
  4. What are NR and FNR and what does “NR==FNR” imply?
  5. How do I find the text that matches a pattern?
  6. How to delete a line from the file with php?
  7. Escaping separator within double quotes, in awk
  8. Is a /start/,/end/ range expression ever useful in awk?
  9. Can we use shell variables in awk?
  10. Summing values of a column using awk command
  11. Using multiple delimiters in awk
  12. Print all but the first three columns
  13. Using AWK to Process Input from Multiple Files
  14. Assigning system command’s output to variable
  15. Why does “1” in awk print the current line?
  16. How to split a delimited string into an array in awk?
  17. How to escape a single quote inside awk
  18. Random numbers generation with awk in BASH shell
  19. How to show only next line after the matched one?
  20. Print second-to-last column/field in `awk`
  21. How can I make awk not use scientific notation when printing small values?
  22. print unique lines based on field
  23. ignorecase in AWK
  24. get the user input in awk
  25. How to preserve the original whitespace between fields in awk?
  26. Split one file into multiple files based on delimiter
  27. Why doesn’t `\d` work in regular expressions in sed? [duplicate]
  28. How to use shell variables in perl command call in a bash shell script?
  29. Extract lines between two patterns from a file [duplicate]
  30. How to draw a directed arrow line in Java?

Leave a Comment