CISC 105 - UNIX help

• Quota Management

  quota -v
  to view the current quota usage

  du -h
  to view the directory structure with sizes. You can then see which directories have the most stuff in them.
  Use du -ak | sort -n | grep M to find the directories and files with more than 1 MB.

  If you have quota problems, do not log out. Delete the culprit large files.

  Examples of what files to delete:

  • Old a.out files. You can regenerate those files later by recompiling your program.
  • core files: these files are generated when an execution goes wrong.
  • mozilla and netscape cache files.
    \rm -r .netscape/cache/*
    or \rm -r .mozilla/cache/*
    The full filenames should show up when you run the above du command.
  • Generated output files

  Ask me if you're unsure if a file can be deleted without consequence.

  Managing files:

  Some people are having problems with their quota because they have an infinite loop that writes to a file until the file becomes too large and exceeds their quota.

  • When writing programs that write output to a file, first, check that the file output works correctly, i.e., .writes to the correct file.
  • Then, change the output file to "stdout" and do your debugging with output printed to the terminal.

• Running programs in the background

  cmd [args] &
  To run a command cmd [args] in the background, follow the full command (including arguments) with an "&"
  For example: emacs &. Emacs opens and the terminal is now available to run other commands.

  If you already started to run the program in the foreground, type 'Control-Z', which suspends the running program and gives you your prompt back. Then, type bg, which puts the suspended program in the background. Now, you can use emacs.

• Manipulating files

  pwd
  present working directory

  cd [dir]
  change directory

  Special names for directories:

  • .
    the current directory
  • ..
    the parent directory
  • ~
    home directory

  ls
  list files in the directory

  cp [srcfile] [destfile]
  copy a file (srcfile) into another file/location (destfile)

  mv [srcfile] [destfile]
  move a file (srcfile) into another file/location (destfile)