Macos – How to clear previous output in Terminal in Mac OS X

buffermacosshell

I know the clear command that 'clears' the current screen, but it does this just by printing lots of newlines – the cleared contents just get scrolled up.

Is there a way to completely wipe all previous output from the terminal so that I can't reach it even by scrolling up?

Best Answer

To clear the terminal manually:

⌘+K

Command+K for newer keyboards

To clear the terminal from within a shell script;

/usr/bin/osascript -e 'tell application "System Events" to tell process "Terminal" to keystroke "k" using command down'

Related Solutions

Bash – How to check if a directory exists in a Bash shell script

To check if a directory exists in a shell script, you can use the following:

if [ -d "$DIRECTORY" ]; then
  # Control will enter here if $DIRECTORY exists.
fi

Or to check if a directory doesn't exist:

if [ ! -d "$DIRECTORY" ]; then
  # Control will enter here if $DIRECTORY doesn't exist.
fi

However, as Jon Ericson points out, subsequent commands may not work as intended if you do not take into account that a symbolic link to a directory will also pass this check. E.g. running this:

ln -s "$ACTUAL_DIR" "$SYMLINK"
if [ -d "$SYMLINK" ]; then 
  rmdir "$SYMLINK" 
fi

Will produce the error message:

rmdir: failed to remove `symlink': Not a directory

So symbolic links may have to be treated differently, if subsequent commands expect directories:

if [ -d "$LINK_OR_DIR" ]; then 
  if [ -L "$LINK_OR_DIR" ]; then
    # It is a symlink!
    # Symbolic link specific commands go here.
    rm "$LINK_OR_DIR"
  else
    # It's a directory!
    # Directory command goes here.
    rmdir "$LINK_OR_DIR"
  fi
fi

Take particular note of the double-quotes used to wrap the variables. The reason for this is explained by 8jean in another answer.

If the variables contain spaces or other unusual characters it will probably cause the script to fail.

Git – How to Remove .DS_Store files from a Git repository

Remove existing files from the repository:

find . -name .DS_Store -print0 | xargs -0 git rm -f --ignore-unmatch

Add this line:

.DS_Store

to the file .gitignore, which can be found at the top level of your repository (or create the file if it isn't there already). You can do this easily with this command in the top directory:

echo .DS_Store >> .gitignore

Then commit the file to the repo:

git add .gitignore
git commit -m '.DS_Store banished!'