44 lines
1.2 KiB
Markdown
44 lines
1.2 KiB
Markdown
---
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tags:
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- C语言
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- Linux
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aliases:
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- 小知识
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日期: 2026/1/23
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---
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- 字符类型数字转整形数字要 `-'0'`
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```c
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char arr[10];
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for(int i = 0;i < strlen(arr);i++)
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num = num * 10 + arr[i] - '0';
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```
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- Linux重新加载配置文件命令
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```shell
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shource ~/.bashrc #重载bashrc文件
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```
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- Linux写脚本
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```shell
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vim mount_hgfs
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sudo vmhgfs-fuse .host:/ /mnt/hgfs/ -o allow_other #填入命令
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chmod +x mount_hgfs #增加执行权限
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mv mount_hgfs /bin #移动到/bin路径下 以后使用 mount_hgfs 直接执行
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```
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- C语言`&&`运算符的左值为假时，右值不进行计算，同理`||`运算符左值为真右值不进行计算
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- 按位异或`^，a ^ b = c , a ^ c = b , b ^ c = a;`,可用于进行数的交换（省去中间值）
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- C语言左移`<<`就是与2的x次方相乘，右移为相除
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- 简便运算后有括号`a *= 5+8 ==> a = a * (5 + 8)`，赋值运算符的优先级很低
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- C语言中` ... `表示范围赋值
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```c
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int arr[10] = {[0 ...3] = 24, [6 ...9] = 12};
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//or
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switch (num)
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{
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case 90 ...100:
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printf("LEVEL: A \n");
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break;
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default:
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printf("What are you doing baby ? \n");
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break;
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}
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```
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- 函数的名称与数组的名称一样，是函数的首地址 |