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### [sort](https://blog.gtwang.org/linux/linux-sort-command-tutorial-and-examples/)
```bash
#!/bin/bash

rm /tmp/some.txt
echo "TrueOS,$(( $RANDOM % 10 + 1 )),$(( $RANDOM % 100 ))" >> /tmp/some.txt
echo "Mint,$(( $RANDOM % 10 + 1 )),$(( $RANDOM % 100 ))" >> /tmp/some.txt
echo "Debian,$(( $RANDOM % 10 + 1 )),$(( $RANDOM % 100 ))" >> /tmp/some.txt
echo "Solus,$(( $RANDOM % 10 + 1 )),$(( $RANDOM % 100 ))" >> /tmp/some.txt
echo "Ubuntu,$(( $RANDOM % 10 + 1 )),$(( $RANDOM % 100 ))" >> /tmp/some.txt
echo "Antergos,$(( $RANDOM % 10 + 1 )),$(( $RANDOM % 100 ))" >> /tmp/some.txt
echo "elementary,$(( $RANDOM % 10 + 1 )),$(( $RANDOM % 100 ))" >> /tmp/some.txt
echo "Manjaro,$(( $RANDOM % 10 + 1 )),$(( $RANDOM % 100 ))" >> /tmp/some.txt
echo "openSUSE,$(( $RANDOM % 10 + 1 )),$(( $RANDOM % 100 ))" >> /tmp/some.txt
echo "Fedora,$(( $RANDOM % 10 + 1 )),$(( $RANDOM % 100 ))" >> /tmp/some.txt

sort /tmp/some.txt
echo "--------------------------------------------------"
cat /tmp/some.txt | sort
echo "反向排序"
sort -r /tmp/some.txt
echo "根據各行特定欄位排序"
echo "-t, 之後串接「分隔符號」"
echo "-ka,b a表示起始位置，b表示結束位置"
sort -t, -k2,2 -n /tmp/some.txt
echo "--------------------------------------------------"
sort -t, -k2 /tmp/some.txt
```

### [uniq 移除重覆內容](https://blog.gtwang.org/linux/linux-uniq-command-tutorial/)
serial.txt 檔案內容
```
10 => wAwbwCM8x7
11 => wAwbwCM8x7
12 => iwFSRivUPlVI
13 => wAwbwCM8x7
14 => iwFSRivUPlVI
14 => iwFSRivUPlVI
```
```bash
uniq -s 2 serial.txt # 略過前兩個字元
10 => wAwbwCM8x7
12 => iwFSRivUPlVI
13 => wAwbwCM8x7
14 => iwFSRivUPlVI
```
serial.txt 檔案內容
```
wAwbwCM8x7
wAwbwCM8x7
iwFSRivUPlVI
wAwbwCM8x7
iwFSRivUPlVI
iwFSRivUPlVI
```
```bash
uniq serial.txt #刪除重覆行
wAwbwCM8x7
iwFSRivUPlVI
wAwbwCM8x7
iwFSRivUPlVI

sort serial.txt | uniq #排序後刪除重覆行
iwFSRivUPlVI
wAwbwCM8x7
```

### [How to sort lines of text files in Linux?](https://www.tutorialspoint.com/how-to-sort-lines-of-text-files-in-linux)
```bash
sort text.txt > newtext.txt
```

---

# 找出重複行

## ✅ 常見作法

### 1. 直接找出重複行

```bash
sort file.txt | uniq -d
```

* `sort`：先排序（uniq 只會檢查相鄰行）
* `uniq -d`：只顯示重複的行（只輸出一次，不重複列出）

---

### 2. 找出每行出現次數

```bash
sort file.txt | uniq -c
```

輸出範例：

```
   1 apple
   3 banana
   2 cherry
```

👉 前面的數字就是出現次數。

---

### 3. 只列出出現超過 1 次的行（含次數）

```bash
sort file.txt | uniq -c | awk '$1 > 1'
```

結果：

```
   3 banana
   2 cherry
```

---

### 4. 只列出唯一的行（沒有重複的）

```bash
sort file.txt | uniq -u
```

---

## 🔑 總結

* `sort file | uniq -d` → 找重複行
* `sort file | uniq -c` → 計數
* `sort file | uniq -u` → 找唯一行

---

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