Networking / Beginners

Wildcards

Wildcards are one of the most powerful features of command shells. With wildcards, you can process all the files that match a particular naming pattern with a single command. For example, suppose that you have a folder with 500 files in it, and you want to delete all the files that contain the letters Y2K and end with .doc, which happens to be 50 files. If you try to do this in GNOME, you'll spend ten minutes picking these files out from the list. From a shell, you can delete them all with the single command rm *Y2K*.doc.

You can use two basic wildcard characters. An asterisk (*) stands for any number of characters, including zero, while an exclamation mark (!) stands for just one character. Thus, !Text.doc matches files with names like aText.doc, xText.doc, and 4Text.doc, but not abcText.doc or just Text.doc. However, *Text.doc would match any of the names I mentioned.

You can also use brackets to indicate a range of characters to choose from. For example, report[123] matches the files report1, report2, or report3. You can also specify report[1-5] to match report1, report2, report3, report4, or report5. The wildcard r[aeiou]port matches files named raport, report, riport, roport, or ruport. As you can see, the possibilities are almost endless.

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In this tutorial:

  1. Linux Commands
  2. Command Shell Basics
  3. Editing commands
  4. Wildcards
  5. Redirection and piping
  6. Environment variables
  7. Shell scripts
  8. Directory and File Handling Commands
  9. The cd command
  10. The mkdir command
  11. The rmdir command
  12. The ls command
  13. The cp command
  14. The rm command
  15. The mv command
  16. The touch command
  17. The cat command
  18. Commands for Working with Packages and Services
  19. The rpm command
  20. Commands for Administering Users
  21. The usermod command
  22. The chage command
  23. The passwd command
  24. The newusers command
  25. The groupadd command
  26. The groupdel command
  27. Commands for Managing Ownership and Permissions
  28. The chgrp command
  29. The chmod command
  30. Networking Commands
  31. The ipconfig command
  32. The netstat command
  33. The ping command
  34. The route command
  35. The traceroute command