Hdi2u S13

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Reading text files

  • These are useful when you want to look at the contents of a file, but not edit it.
  • Among the most common of these commands are cat, more, and less.
  • cat simply prints out one or several files out.
  • Useful for small files, but also for concatenating (which is where it got its name)
  • more and less are pagers
  • You can feed output to them via the pipe operator
  • they have keybindings similar to the editor vi: /, ?, gg. G.

Exercises

  • Move into the hdi2u_files directory.
  • Read the file hsy14768.embl using the commands cat, more and less.
  • Don’t forget that tab completion can save you typing effort.
cat hsy14768.embl
more hsy14768.embl
less hsy14768.embl
  • Use the spacebar to scroll down
  • Press q to quit.
  • Use the spacebar to scroll down, b to go up a page, and the up and down arrow keys to move up and down the file line by line.
  • Press the / key and search for the letters sequen in the file.
  • Press the ? key and search for the letters gene in the file.
  • Press the n key to search for other instances of gene in the file.