Sometime I run one or the other command in Terminal that generates a huge output - I may even do it a few times - to then have to scroll back and see what the original command was. For this purpose I wanted to have the Bash prompt bold.

So for example instead of this:

MAC_PRO:~ hans$ ls
Applications	Downloads	MountPoints	Pictures	tmp
Desktop		Dropbox		Movies		Public
Documents	Library		Music

I'd like to see this:

MAC_PRO:~ hans$ ls
Applications	Downloads	MountPoints	Pictures	tmp
Desktop		Dropbox		Movies		Public
Documents	Library		Music	

To accomplish this, I would have to need to change the "PS1" environment variable, which by default is:

"\h:\W \u\$ "

(below you'll find a comprehensive list of codes you can use in your prompt, for example time stamp etc)

To make the prompt bold you'd need to change the value of PS1 as follows:

export PS1="\[\033[1m\]\h:\W \u\$\[\033[m\] "

Here \[\033[1m\] starts bold and \[\033[m\] ends bold.
\h = hostname, \W = basename directory, \u = username and a space to keep it what ever you type separated.

Now this will disappear when closing Terminal and you'd have to set this each time - quite annoying of course.
To make it permanent, you'll need to create (or edit) the file ~/.bash_profile and add the export line there (at the end or beginning - it doesn't seem to matter where).

See the effect in action in the attached screenshot.

Note: Some more options to add to your bash prompt;

\a         # an ASCII bell character (07)
\d         # the date in "Weekday Month Date" format (e.g., "Tue May 26")
\D{format} # the format is passed to strftime(3) and the result
           # is inserted into the prompt string an empty format
           # results in a locale-specific time representation.
           # The braces are required
\e         # an ASCII escape character (033)
\h         # the hostname up to the first '.'
\H         # the hostname
\j         # the number of jobs currently managed by the shell
\l         # the basename of the shell's terminal device name
\n         # newline
\r         # carriage return
\s         # the name of the shell, the basename of $0 (the portion following
           #   the final slash)
\t         # the current time in 24-hour HH:MM:SS format
\T         # the current time in 12-hour HH:MM:SS format
\@         # the current time in 12-hour am/pm format
\A         # the current time in 24-hour HH:MM format
\u         # the username of the current user
\v         # the version of bash (e.g., 2.00)
\V         # the release of bash, version + patch level (e.g., 2.00.0)
\w         # the current working directory, with $HOME abbreviated with a tilde
\W         # the basename of the current working directory, with $HOME
           # abbreviated with a tilde
\!         # the history number of this command
\#         # the command number of this command
\$         # if the effective UID is 0, a #, otherwise a $
\nnn       # the character corresponding to the octal number nnn
\\         # a backslash
\[         # begin a sequence of non-printing characters, which could be used
           #   to embed a terminal control sequence into the prompt
\]         # end a sequence of non-printing characters