# shell终端输出内容美化

> 作者：James Zhu (<fatindeed@hotmail.com>)
>
> 创建日期：2018-05-30

## 引言

我们在编写shell脚本（如bash/sh等）时，有时会因为输出内容过多而观察不便，因此需要将一些重要信息高亮显示。

**ANSI转义序列**是一种*In-band signaling*的转义序列标准，用于控制视频文本终端上的光标位置、颜色和其他选项。在文本中嵌入确定的字节序列，大部分以`ESC`转义字符和`[`字符开始，终端会把这些字节序列解释为相应的指令，而不是普通的字符编码。

## ANSI转义序列表（不完整列表）

### Set

| Code | Description | Example                            |
| ---- | ----------- | ---------------------------------- |
| 1    | Bold/Bright | `echo -e "Normal \e[1mBold"`       |
| 2    | Dim         | `echo -e "Normal \e[2mDim"`        |
| 4    | Underlined  | `echo -e "Normal \e[4mUnderlined"` |
| 5    | Blink       | `echo -e "Normal \e[5mBlink"`      |
| 7    | Reverse     | `echo -e "Normal \e[7minverted"`   |
| 8    | Hidden      | `echo -e "Normal \e[8mHidden"`     |

### Unset

| Code | Description          | Example                                         |
| ---- | -------------------- | ----------------------------------------------- |
| 0    | Reset all attributes | `echo -e "\e[0mNormal Text"`                    |
| 21   | Reset bold/bright    | `echo -e "Normal \e[1mBold \e[21mNormal"`       |
| 22   | Reset dim            | `echo -e "Normal \e[2mDim \e[22mNormal"`        |
| 24   | Reset underlined     | `echo -e "Normal \e[4mUnderlined \e[24mNormal"` |
| 25   | Reset blink          | `echo -e "Normal \e[5mBlink \e[25mNormal`       |
| 27   | Reset reverse        | `echo -e "Normal \e[7minverted \e[27mNormal"`   |
| 28   | Reset hidden         | `echo -e "Normal \e[8mHidden \e[28mNormal"`     |

### Foreground (text)

| Code | Description              | Example                                 |
| ---- | ------------------------ | --------------------------------------- |
| 39   | Default foreground color | `echo -e "Default \e[39mDefault"`       |
| 30   | Black                    | `echo -e "Default \e[30mBlack"`         |
| 31   | Red                      | `echo -e "Default \e[31mRed"`           |
| 32   | Green                    | `echo -e "Default \e[32mGreen"`         |
| 33   | Yellow                   | `echo -e "Default \e[33mYellow"`        |
| 34   | Blue                     | `echo -e "Default \e[34mBlue"`          |
| 35   | Magenta                  | `echo -e "Default \e[35mMagenta"`       |
| 36   | Cyan                     | `echo -e "Default \e[36mCyan"`          |
| 37   | Light gray               | `echo -e "Default \e[37mLight gray"`    |
| 90   | Dark gray                | `echo -e "Default \e[90mDark gray"`     |
| 91   | Light red                | `echo -e "Default \e[91mLight red"`     |
| 92   | Light green              | `echo -e "Default \e[92mLight green"`   |
| 93   | Light yellow             | `echo -e "Default \e[93mLight yellow"`  |
| 94   | Light blue               | `echo -e "Default \e[94mLight blue"`    |
| 95   | Light magenta            | `echo -e "Default \e[95mLight magenta"` |
| 96   | Light cyan               | `echo -e "Default \e[96mLight cyan"`    |
| 97   | White                    | `echo -e "Default \e[97mWhite"`         |

### Background

| Code | Description              | Example                                  |
| ---- | ------------------------ | ---------------------------------------- |
| 49   | Default background color | `echo -e "Default \e[49mDefault"`        |
| 40   | Black                    | `echo -e "Default \e[40mBlack"`          |
| 41   | Red                      | `echo -e "Default \e[41mRed"`            |
| 42   | Green                    | `echo -e "Default \e[42mGreen"`          |
| 43   | Yellow                   | `echo -e "Default \e[43mYellow"`         |
| 44   | Blue                     | `echo -e "Default \e[44mBlue"`           |
| 45   | Magenta                  | `echo -e "Default \e[45mMagenta"`        |
| 46   | Cyan                     | `echo -e "Default \e[46mCyan"`           |
| 47   | Light gray               | `echo -e "Default \e[47mLight gray"`     |
| 100  | Dark gray                | `echo -e "Default \e[100mDark gray"`     |
| 101  | Light red                | `echo -e "Default \e[101mLight red"`     |
| 102  | Light green              | `echo -e "Default \e[102mLight green"`   |
| 103  | Light yellow             | `echo -e "Default \e[103mLight yellow"`  |
| 104  | Light blue               | `echo -e "Default \e[104mLight blue"`    |
| 105  | Light magenta            | `echo -e "Default \e[105mLight magenta"` |
| 106  | Light cyan               | `echo -e "Default \e[106mLight cyan"`    |
| 107  | White                    | `echo -e "Default \e[107mWhite"`         |

## 参考资料

* [ANSI escape code](https://en.wikipedia.org/wiki/ANSI_escape_code)
* [Bash tips: Colors and formatting](https://misc.flogisoft.com/bash/tip_colors_and_formatting)