Main function: Search the man/whatis database for manual page names and descriptions matching a keyword
在 man/whatis 数据库中按照关键字搜索相关手册描述，命令名字和简短描述
Syntax:apropos [keyword] <=> man -k [keyword]
sudo
答案 点击查看
Main function: Run commands as another user, (default is root), typically for temporary privilege elevation. The most common use is to run command with administrator/superuser privileges
Syntax:sudo [command] or sudo -u username [command]
df
答案 点击查看
Main function: Shows disk space usage of mounted file systems
显示挂载的文件系统的磁盘使用情况
Syntax:df [option] [filesystem]
df -i Displays inode usage instead of disk block usage
df -k Displays disk usage in kilobytes (KB)
xterm
答案 点击查看
Main function: Opens a terminal window under the X Window System ｜ 打开一个X Window系统的终端窗口
语法 Syntax:
bash
xterm [options]
#举例子
xterm -e top
xterm -e "bash"
xterm -e [command] 表示打开xterm终端并且执行command ｜ Open an xterm terminal and execute the command.
gdb
答案 点击查看
Main function: GNU debugger for debugging programs ｜ GNU调试工具,用于调试程序
gdb is used to locate and debug program errors，Breakpoints, step execution, and variable inspection are core features。
Syntax:
bash
gdb [program] [core]
program：Executable file to be debugged ｜ 要调试的可执行文件
core：Core dump file (optional) ｜ core dump 文件（可选）
常用命令 Common commands:
text
- gdb
- list # 列出源代码
# List source code
- br n # 在第 n 行设置断点（br = break）
# Set a breakpoint at line n
- run # 运行程序
# Run the program
- print x # 打印变量 x 的值
# Print the value of variable x
- next # 执行下一行（不进入函数）
# Execute next line without stepping into functions
- where # 显示当前调用的函数和行号
# Show call stack and current line number
- help # 显示可用命令
# Show available commands
- quit # 退出 gdb
# Exit gdb
编译要求 Compile requirement: To enable debugging, compile the program with -g
bash
gcc -g main.c -o main
ln
答案 点击查看
Main function: Creates hard links or symbolic links to files ｜ 创建文件或目录的硬链接/软链接
Syntax:ln [option] source target
-s create symbolic link ｜ 创建符号链接(软链接)
-f force creation ｜ 强制创建,覆盖已存在文件
chmod
答案 点击查看
Main function: Changes file or directory access permissions ｜ 改变文件或目录的访问权限
Syntax:chmod [option] mode file
-R recursively change directories and their contents ｜ 递归修改目录及其内容
mode:
numeric mode (e.g., 755)
symbolic (e.g., u+x)
top
答案 点击查看
Main function: Displays running processes and system resource usage in real-time ｜ 实时显示系统进程和资源使用情况
Syntax:top [options]
-d 设置刷新间隔 set delay time interval
-u 显示指定用户的进程 display specific user's processes
cat
答案 点击查看
Main function: Displays file contents or concatenates files ｜ 显示文件内容或连接多个文件
Changes to ~/src directory, sets all files to 764 permissions (owner: rwx, group: rw-, others: r--), then adds read permission for others to all .png or .Png files.
5.gcc -o tri triangle.c -lm
答案 点击查看
逐字解释:
gcc - GNU C Compiler,GNU C编译器
-o - output,指定输出文件名选项
tri - 输出的可执行文件名
triangle.c - 源代码文件名
-lm - 链接数学库选项
-l - link library,链接库
m - math,数学库
整体翻译:
使用gcc编译器将triangle.c源文件编译为名为tri的可执行文件,并链接数学库。
Compiles triangle.c source file into an executable named tri using gcc compiler, linking the math library.
6.gzip -d cube.tar.gz | tar -tvf cube.tar | tar -xvf cube.tar /home（这条的名称忘了，大概长这样）
1. EDA meaning？Big-3 of EDA company and these product？
答案 点击查看
EDA means Electronic Design Automation, software tools used to design, simulate, verify, and manufacture integrated circuits (ICs) and electronic systems.
Big-3 of EDA
Synopsys
VCS – RTL simulation
Design Compiler – logic synthesis
Cadence
Virtuoso – analog IC design
Siemens EDA (Mentor Graphics)
Questa – simulation
2. Ubuntu，what is it？What mean in Africa？
答案 点击查看
Ubuntu is a Linux operating system based on desktop applications.
Ubuntu is named after the Nguni philosophy of ubuntu, which Canonical indicates means "humanity to others" with a connotation of "I am what I am because of who we all are".
Ubuntu (African meaning) is "I am because where we are"，Meaning: Humanity、Community、Sharing、Mutual respect
3. How to use manul？How to read it in vim？Write other two way to open manul？
答案 点击查看
Basic usage: man ls
Read man page in Vim: man ls | vim - or MANPAGER=vim man ls
Two other ways to open manuals
info: info ls
--help: ls --help (Short and fast reference)
4. Three disk？What change when use them？
答案 点击查看
HDD (Hard Disk Drive)：Mechanical、cheap、slow、large capacity
SSD (Solid State Drive)：Flash memory、Fast、No moving parts、Expensive per GB
NVMe SSD：Uses PCIe bus、Much faster than SATA SSD、Low latency
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