linux-alias的使用（定义自己习惯的命令）

在使用Ubuntu的过程中，有些命令在输入中十分的不顺手，部分是不熟练的原因，也有有一部分是习惯的原因，利用用惯了Windows下的shell或powershell，在清屏的时候习惯的使用cls，而在Linux下为clear，十分的不习惯，在Linux下有可以使用alias进行自定义，定义出自己的习惯的命令。

语法：alias [别名]=[指令名称]

alias cls='clear'

在Terminal下，输入上面的代码就可以将cls和clear有同样的功能，不过在开关机之后这样的命令的就失效了，只能暂时的使用。

如果想在每次打开Terminal，使用清屏的时候都是cls替代clear,可以在.bashrc下进行修改

打开.bashrc文件可以看到下面的内容（在下面的文件已经对cls替代clear进行了修改98行），使用vim或其他的编译器对.bashrc进行修改，并保存，重新打开Terminal，就可以使用cls命令了。

     1  # ~/.bashrc: executed by bash(2) for non-login shells.
     2  # see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)
     3  # for examples
     4  
     5  # If not running interactively, don't do anything
     6  case $- in
     7      *i*) ;;
     8        *) return;;
     9  esac
    10  
    11  # don't put duplicate lines or lines starting with space in the history.
    12  # See bash(1) for more options
    13  HISTCONTROL=ignoreboth
    14  
    15  # append to the history file, don't overwrite it
    16  shopt -s histappend
    17  
    18  # for setting history length see HISTSIZE and HISTFILESIZE in bash(1)
    19  HISTSIZE=1000
    20  HISTFILESIZE=2000
    21  
    22  # check the window size after each command and, if necessary,
    23  # update the values of LINES and COLUMNS.
    24  shopt -s checkwinsize
    25  
    26  # If set, the pattern "**" used in a pathname expansion context will
    27  # match all files and zero or more directories and subdirectories.
    28  #shopt -s globstar
    29  
    30  # make less more friendly for non-text input files, see lesspipe(1)
    31  [ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"
    32  
    33  # set variable identifying the chroot you work in (used in the prompt below)
    34  if [ -z "${debian_chroot:-}" ] && [ -r /etc/debian_chroot ]; then
    35      debian_chroot=$(cat /etc/debian_chroot)
    36  fi
    37  
    38  # set a fancy prompt (non-color, unless we know we "want" color)
    39  case "$TERM" in
    40      xterm-color|*-256color) color_prompt=yes;;
    41  esac
    42  
    43  # uncomment for a colored prompt, if the terminal has the capability; turned
    44  # off by default to not distract the user: the focus in a terminal window
    45  # should be on the output of commands, not on the prompt
    46  #force_color_prompt=yes
    47  
    48  if [ -n "$force_color_prompt" ]; then
    49      if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
    50      # We have color support; assume it's compliant with Ecma-48
    51      # (ISO/IEC-6429). (Lack of such support is extremely rare, and such
    52      # a case would tend to support setf rather than setaf.)
    53      color_prompt=yes
    54      else
    55      color_prompt=
    56      fi
    57  fi
    58  
    59  if [ "$color_prompt" = yes ]; then
    60      PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\[email protected]\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
    61  else
    62      PS1='${debian_chroot:+($debian_chroot)}\[email protected]\h:\w\$ '
    63  fi
    64  unset color_prompt force_color_prompt
    65  
    66  # If this is an xterm set the title to [email protected]:dir
    67  case "$TERM" in
    68  xterm*|rxvt*)
    69      PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\[email protected]\h: \w\a\]$PS1"
    70      ;;
    71  *)
    72      ;;
    73  esac
    74  
    75  # enable color support of ls and also add handy aliases
    76  if [ -x /usr/bin/dircolors ]; then
    77      test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"
    78      alias ls='ls --color=auto'
    79      #alias dir='dir --color=auto'
    80      #alias vdir='vdir --color=auto'
    81  
    82      alias grep='grep --color=auto'
    83      alias fgrep='fgrep --color=auto'
    84      alias egrep='egrep --color=auto'
    85  fi
    86  
    87  # colored GCC warnings and errors
    88  #export GCC_COLORS='error=01;31:warning=01;35:note=01;36:caret=01;32:locus=01:quote=01'
    89  
    90  # some more ls aliases
    91  alias ll='ls -alF'
    92  alias la='ls -A'
    93  alias l='ls -CF'
    94  alias cls='cls'
    95  
    96  # ------begin----------
    97  # person aliases
    98  alias cls='clear'
    99  
   100  
   101  # ------end----------
   102  
   103  # Add an "alert" alias for long running commands.  Use like so:
   104  #   sleep 10; alert
   105  alias alert='notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo error)" "$(history|tail -n1|sed -e '\''s/^\s*[0-9]\+\s*//;s/[;&|]\s*alert$//'\'')"'
   106  
   107  # Alias definitions.
   108  # You may want to put all your additions into a separate file like
   109  # ~/.bash_aliases, instead of adding them here directly.
   110  # See /usr/share/doc/bash-doc/examples in the bash-doc package.
   111  
   112  if [ -f ~/.bash_aliases ]; then
   113      . ~/.bash_aliases
   114  fi
   115  
   116  # enable programmable completion features (you don't need to enable
   117  # this, if it's already enabled in /etc/bash.bashrc and /etc/profile
   118  # sources /etc/bash.bashrc).
   119  if ! shopt -oq posix; then
   120  
   121    if [ -f /usr/share/bash-completion/bash_completion ]; then
   122      . /usr/share/bash-completion/bash_completion
   123    elif [ -f /etc/bash_completion ]; then
   124      . /etc/bash_completion
   125    fi
   126  fi