我不知道什么是原因。 我将解释所遵循的步骤。

 Ubuntu:~$ which ruby
 /usr/local/bin/ruby
 $ bash < <( curl https://rvm.beginrescueend.com/releases/rvm-install-head )

修改了Bashrc文档。 我的档案

# ~/.bashrc: executed by bash(1) for non-login shells.
# see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)
# for examples

# If not running interactively, don t do anything
if [[ -n "$PS1" ]]; then

# don t put duplicate lines in the history. See bash(1) for more options
# ... or force ignoredups and ignorespace
HISTCONTROL=ignoredups:ignorespace

# append to the history file, don t overwrite it
shopt -s histappend

# for setting history length see HISTSIZE and HISTFILESIZE in bash(1)
HISTSIZE=1000
HISTFILESIZE=2000

# check the window size after each command and, if necessary,
# update the values of LINES and COLUMNS.
shopt -s checkwinsize

# make less more friendly for non-text input files, see lesspipe(1)
[ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"

# set variable identifying the chroot you work in (used in the prompt below)
if [ -z "$debian_chroot" ] && [ -r /etc/debian_chroot ]; then
    debian_chroot=$(cat /etc/debian_chroot)
fi

# set a fancy prompt (non-color, unless we know we "want" color)
case "$TERM" in
    xterm-color) color_prompt=yes;;
esac

# uncomment for a colored prompt, if the terminal has the capability; turned
# off by default to not distract the user: the focus in a terminal window
# should be on the output of commands, not on the prompt
#force_color_prompt=yes

if [ -n "$force_color_prompt" ]; then
    if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
    # We have color support; assume it s compliant with Ecma-48
    # (ISO/IEC-6429). (Lack of such support is extremely rare, and such
    # a case would tend to support setf rather than setaf.)
    color_prompt=yes
    else
    color_prompt=
    fi
fi

if [ "$color_prompt" = yes ]; then
    PS1= ${debian_chroot:+($debian_chroot)}[33[01;32m]u@h[33[00m]:[33[01;34m]w[33[00m]$  
else
    PS1= ${debian_chroot:+($debian_chroot)}u@h:w$  
fi
unset color_prompt force_color_prompt

# If this is an xterm set the title to user@host:dir
case "$TERM" in
xterm*|rxvt*)
    PS1="[e]0;${debian_chroot:+($debian_chroot)}u@h: wa]$PS1"
    ;;
*)
    ;;
esac

# enable color support of ls and also add handy aliases
if [ -x /usr/bin/dircolors ]; then
    test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"
    alias ls= ls --color=auto 
    #alias dir= dir --color=auto 
    #alias vdir= vdir --color=auto 

    alias grep= grep --color=auto 
    alias fgrep= fgrep --color=auto 
    alias egrep= egrep --color=auto 
fi

# some more ls aliases
alias ll= ls -alF 
alias la= ls -A 
alias l= ls -CF 

# Add an "alert" alias for long running commands.  Use like so:
#   sleep 10; alert
alias alert= notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo error)" "$(history|tail -n1|sed -e    s/^s*[0-9]+s*//;s/[;&|]s*alert$//   )" 

# Alias definitions.
# You may want to put all your additions into a separate file like
# ~/.bash_aliases, instead of adding them here directly.
# See /usr/share/doc/bash-doc/examples in the bash-doc package.

if [ -f ~/.bash_aliases ]; then
    . ~/.bash_aliases
fi

# enable programmable completion features (you don t need to enable
# this, if it s already enabled in /etc/bash.bashrc and /etc/profile
# sources /etc/bash.bashrc).
if [ -f /etc/bash_completion ] && ! shopt -oq posix; then
    . /etc/bash_completion
fi

if [[ -s $HOME/.rvm/scripts/rvm ]] ; then source $HOME/.rvm/scripts/rvm ; fi

fi

Now when i do rvm notes ,it says "No command rvm found, but there are 20 similar ones rvm: command not found"

无法说明一犯错误之处。