###### tags: `tutorials` `linux` `ubuntu`
# 修改使用者設定檔 `~/.bashrc`
:::warning
最好在修改之前先備份

$ cp ~/.bashrc ~/.bashrc_bk

:::
## 修改 `~/.bashrc`
### Set prompt style
- 約 46 行: 將 `force_color_prompt=yes` 取消註解以開啟 bash 顯示顏色
- 約 60 行: 修改 `PS1` 改顏色 (修改 `\[\XXX[XX;XX\]`)
- 原始 `PS1`
~~~bash= !
PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
~~~
- 效果為 <span style="background:black"><font color="#4e9a06">{user_name}@{host_name}</font><font color="white">:</font><font color="#32afff">{work_path}</font><font color="white">$</font>&nbsp;</span>
- 修改為
~~~bash= !
PS1='${debian_chroot:+($debian_chroot)}\[\033[1;36m\]\u\[\033[01;33m\]@\[\033[01;31m\]\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
~~~
- 效果為 <span style="background:black"><font color="#06989a">{user_name}</font><font color="c4a000">@</font><font color="#ef2929">{host_name}</font><font color="white">:</font><font color="#32afff">{work_path}</font><font color="white">$</font>&nbsp;</span>
- `\u`: user name，使用者名稱
- `\h`: host name，電腦名稱
- `\w`: work path，當前工作路徑

:::info
簡單來說就是
1. 將 `\u` 之前的 `\[\033[01;32m\]` 修改為 `\[\033[1;36m\]`
2. 在 `@` 之前加入 `\[\033[01;33m\]`
3. 在 `\h` 之前加入 `\[\033[01;31m\]`
:::

:::spoiler linux color code
|color|code|light color|code|
|-|-|-|-|
|Black |0;30|Dark Gray |1;30|
|Red |0;31|Light Red |1;31|
|Green |0;32|Light Green |1;32|
|Brown/Orange |0;33|Yellow |1;33|
|Blue |0;34|Light Blue |1;34|
|Purple |0;35|Light Purple |1;35|
|Cyan |0;36|Light Cyan |1;36|
|Light Gray |0;37|White |1;37|
:::

:::spoiler lazy mode

$ cp ~/.bashrc ~/.bashrc_bk && sed -i '0,/PS1.*/ s/PS1.*/'"\PS1=\'\$\{debian_chroot:\+\(\$debian_chroot\)\}\\\[\\\033\[01;36m\\\]\\\u\\\[\\\033\[00;33m\\\]@\\\[\\\033\[01;31m\\\]\\\h\\\[\\\033\[00m\\\]:\\\[\\\033\[01;34m\\\]\\\w\\\[\\\033\[00m\\\]$ \'"'/' ~/.bashrc && sed -i 's/^#force_color_prompt=yes/force_color_prompt=yes/' ~/.bashrc

:::

---

### Auto call `~/.bash_aliases` when open new shell
- 如果 `~/.bash_aliases` 存在，之後進 bash 會由 `~/.bashrc` 呼叫 `~/.bash_aliases` 並自動設定
- 編輯 `~/.bash_rc`

    $ vim ~/.bash_rc

- 內容填入
~~~bash= !
if [ -f ~/.bash_aliases ]; then
source ~/.bash_aliases
fi
~~~
:::danger
- 預設 `~/.bash_aliases` 只會在第一次登入的 bash 呼叫一次，之後再開的 bash 不會套用
- `~/.bash_profile` 同上，若要所有 shell 都套用設置只需把上述內容的 `~/.bash_aliases` 都修改為`~/.bash_profile` 即可
:::

:::spoiler bash flow

digraph G {
  node [];
  edge [];

  splines="ortho";
  rankdir="LR"
  
  empty [
    label = "";
    shape=box;
    width=0;
    height=0;
    color="#FFFFFFFF"
  ]
  empty2 [
    label = "";
    shape=box;
    width=0;
    height=0;
    color="#FFFFFFFF"
  ]
  empty3 [
    label = "";
    shape=box;
    width=0;
    height=0;
    color="#FFFFFFFF"
  ]
  empty4 [
    label = "";
    shape=box;
    width=0;
    height=0;
    color="#FFFFFFFF"
  ]
  empty5 [
    label = "";
    shape=box;
    width=0;
    height=0;
    color="#FFFFFFFF"
  ]
  empty5 [
    label = "";
    shape=box;
    width=0;
    height=0;
    color="#FFFFFFFF"
  ]
  login [
    label = "login shell";
    shape = oval;
  ];
  new_shell [
    label = "open new shell";
    shape = oval;
  ];
  prompt [
    label = "bash prompt";
    shape = oval;
  ];
  ep_ex [
    label = "/etc/profile\nexists";
    shape = diamond;
  ];
  sp [
    label = "source /etc/profile";
    shape = rect;
  ];
  rp_sh [
    label = "run all .sh\nunder /etc/profile.d folder";
    shape = rect;
  ];
  bp_ex [
    label = "~/.bash_profile\nexists";
    shape = diamond;
  ];
  sbp [
    label = "source ~/.bash_profile";
    shape = rect;
  ];
  br_ex [
    label = "~/.bashrc\nexists";
    shape = diamond;
  ];
  sbr [
    label = "source ~/.bashrc";
    shape = rect;
  ];
  ebr_ex [
    label = "/etc/bashrc\nexists";
    shape = diamond;
  ];
  sebr [
    label = "source /etc/bashrc";
    shape = rect;
  ];
  
  empty -> empty2 [style=invis];
  login -> ep_ex;
  new_shell -> br_ex;
  ep_ex -> sp [ xlabel = "Y"; color=Green ];
  sp -> rp_sh;
  rp_sh -> bp_ex;
  bp_ex -> sbp [ label = "Y"; color=Green ];
  sbp -> prompt [style=invis];
  bp_ex -> empty3 [ arrowhead=none; color=Red; ];
  prompt -> empty3 [ label = "N"; color=Red; dir=back ];
  sbp -> br_ex;
  br_ex -> sbr [ label = "Y"; color=Green ];
  br_ex -> empty4  [ label = "N"; arrowhead=none; color=Red; ];
  empty4 -> prompt [ color=Red; ];
  sbr -> ebr_ex;
  ebr_ex -> sebr [ label = "Y"; color=Green ];
  ebr_ex -> empty4 [ label = "N"; arrowhead=none; color=Red; ];
  sebr -> prompt;
  ep_ex -> empty [arrowhead=none; color=Red;];
  empty -> bp_ex [ label = "N"; color=Red; ];
  login -> new_shell [style=invis];
  

  {
    rank=same;
    login; ep_ex; sp; rp_sh; bp_ex; empty2; empty3;
  }
  
  {
    rank=same;
    sbp;
  }
  
  {
    rank=same;
    br_ex; sbr; prompt; ebr_ex; sebr; new_shell;
  }
  
  {
    rank=min;
    empty
  }
  
  {
    rank=max;
    empty4;
  }
}

:::

:::spoiler lazy mode

$ echo -e "if [ -f ~/.bash_aliases ]; then\n    source ~/.bash_aliases\nfi" >> ~/.bash_rc

:::

## 修改 `~/.bash_aliases`
- alias 加在 `~/.bash_aliases` 內，**定義自訂快捷指令**，之後進 bash 會由 `~/.bashrc` 呼叫 `~/.bash_aliases` 並自動設定
- 編輯 `~/.bash_aliases` (若不存在，`vim` 指令會自動建立該檔案)

    $ vim ~/.bash_aliases

- 內容填入
~~~bash= !
alias nv='nvidia-smi'
alias wnv='watch -n 1 nvidia-smi'
alias wwnv='watch -n 0.1 nvidia-smi'
~~~
:::info
定義快捷指令，可以以更短、更便捷的指令來呼叫本來想執行的指令
- 這裡是將 `nv` 設定為 `nvidia-smi` 指令，意即只要輸入 `nv` 即為 `nvidia-smi` 指令
:::

:::spoiler lazy mode

$ echo -e "alias nv='nvidia-smi'\nalias wnv='watch -n 1 nvidia-smi'\nalias wwnv='watch -n 0.1 nvidia-smi'" >> ~/.bash_aliases

:::

## 修改 `~/.bash_profile`
- profile 加在 `~/.bash_profile` 內，**定義環境變數**，之後進 bash 會由 `~/.bashrc` 呼叫 `~/.bash_profile` 並自動設定
- 編輯 `~/.bash_profile` (若不存在，`vim` 指令會自動建立該檔案)

    $ vim ~/.bash_profile

- 內容填入
~~~bash= !
# clean up history:
export HISTCONTROL=erasedups:ignoreboth
~~~
:::info
- 避免儲存之前執行的重複指令(連續重複指令按 `↑` 可以只顯示一次)
:::
:::danger
- 預設 `~/.bash_profile` 只會在第一次登入的 bash 呼叫一次，之後再開的 bash 不會套用，若要在所有 bash 都套用，要把這個設定加在 `~/.bashrc` 或者照 [這個](#Auto-call-bash_aliases-when-open-new-shell) 修改
:::

:::spoiler lazy mode

$ echo -e "# clean up history:\nexport HISTCONTROL=erasedups:ignoreboth" >> ~/.bash_profile

:::

## 更改完畢後立即套用設置 (Optional)
~~~bash=
source ~/.bashrc
~~~
:::info
即使不立即套用，之後重開 shell 也會自動套用
:::