OS X Terminal text stacking on top of itself

PS1 environment variable determines what shell's prompt will look like. man bash gives full documentation on it. (There are actually several of them, for different modes).

There are number of files that may be setting it, usually one of ~/.profile, ~/.bashrc, /etc/profile or /etc/bashrc.

If you're going to have color codes or other control sequences inside it, you must wrap them with \[ and \] properly (and NOT wrap normal text), otherwise line editing may become messed up like in your case. I suggest resetting PS1 to the default value then carefully adding coloring back item by item.

For example:

PS1='\[\033[1m\033[32m\]\u@\h \w\[\033[0m\]\$ '
       ^^^^^^^^^^^^^^^            ^^^^^^^

Coloring commands are underlined. Note how they are surrounded with \[ \].

I have the same problem, i found if you change

Advanced > Emulation > Declare terminal as: ANSI.

This solves colored PS1 problem. With Mac Terminal

BUT creates a strange behavior: I found a solution to my problem with @koiyu answer.

https://apple.stackexchange.com/questions/37001/strange-behavior-in-terminal-with-custom-bash-profile/37036#37036

I used to have the same issue due to incorrectly using color codes. Here is my PS1 which solved the issue. Also if you use GIT, then this will be also helpful to show git branch you are working on and if your working tree is dirty or not. Put this in your .profile or .bash_profile

# Git branch in prompt.
parse_git_branch() {
    git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ (\1)/'
}

parse_git_dirty() {
    st=$(git status 2>/dev/null | tail -n 1)
    if [[ $st == "" ]]; then
        echo ''
    elif [[ $st == "nothing to commit (working directory clean)" ]]; then
        echo ''
    elif [[ $st == 'nothing added to commit but untracked files present (use "git add" to track)' ]]; then
        echo '?'
    else
        echo '*'
    fi
}

# coloring the terminal comman line
SB_GREEN="\[\033[1;32m\]"
SB_BLUE="\[\033[1;34m\]"
SB_RED="\[\033[1;31m\]"
SB_NOCOLOR="\[\033[0m\]"
export PS1="$SB_GREEN\u@\h$SB_NOCOLOR: $SB_BLUE\w$SB_GREEN\$(parse_git_branch)$SB_RED\$(parse_git_dirty)$SB_NOCOLOR $ "

Hope this helps.