Inner join on two text files

by

Here’s an awk option, so you can avoid the bash dependency (for portability):

$ awk -F'|' 'NR==FNR{check[$0];next} $2 in check' file2 file1

How does this work?

  • -F'|' — sets the field separator
  • 'NR==FNR{check[$0];next} — if the total record number matches the file record number (i.e. we’re reading the first file provided), then we populate an array and continue.
  • $2 in check — If the second field was mentioned in the array we created, print the line (which is the default action if no actions are provided).
  • file2 file1 — the files. Order is important due to the NR==FNR construct.

More Related Contents:

  1. Joining multiple fields in text files on Unix
  2. grep lines that contain 1 character followed by another character
  3. How to convert DOS/Windows newline (CRLF) to Unix newline (LF) in a Bash script
  4. How do I test if a variable is a number in Bash?
  5. sed command with -i option failing on Mac, but works on Linux
  6. How does “cat
  7. Redirect all output to file in Bash [duplicate]
  8. Bash script processing limited number of commands in parallel
  9. Execute bash script from URL
  10. How to find out line-endings in a text file?
  11. Bash script: bad interpreter
  12. How to insert a text at the beginning of a file?
  13. How do I deal with a filename that starts with the hyphen (-) character?
  14. ‘find -exec’ a shell function in Linux
  15. How to determine if a process runs inside lxc/Docker?
  16. How to limit user commands in Linux [closed]
  17. Get current time in seconds since the Epoch on Linux, Bash
  18. How can I run a function from a script in command line?
  19. Add file extension to files with bash
  20. How to escape a single quote in single quote string in Bash?
  21. Bash Script – iterating over output of find
  22. Insert multiple lines into a file after specified pattern using shell script
  23. What is the difference between double-ampersand (&&) and semicolon (;) in Linux Bash?
  24. How do I script a “yes” response for installing programs?
  25. Print date for the monday of the current week (in bash)
  26. How do you filter out all unique lines in a file?
  27. Counter increment in Bash loop not working
  28. Start script after another one (already running) finishes
  29. Problem with Bash output redirection [duplicate]
  30. bash: set array env variable and de-referencing it from any shell script fails

Leave a Comment