Linux系统有什么常用命令

Linux系统有什么常用命令

Linux操作系统是一种开源的、免费的、基于UNIX的多用户操作系统，具有稳定、安全、高效、灵活等特点，在Linux系统中，有许多命令行工具可以帮助我们完成各种任务，本文将介绍一些常用的Linux命令，帮助大家更好地了解和使用Linux系统。

文件操作命令

1、ls

ls(list)命令用于列出目录中的文件和子目录，基本语法如下：

ls [选项] [文件或目录]

常用选项：

-a:显示所有文件，包括隐藏文件(以.开头的文件);

-l:以长格式显示文件信息；

-h:以易读的方式显示文件大小(如K、M、G等单位);

-t:按修改时间排序。

示例：

ls -alh

2、cd

cd(change directory)命令用于切换当前工作目录，基本语法如下：

cd [目录]

示例：

cd /home/user/Documents

3、pwd

pwd(print working directory)命令用于显示当前工作目录的绝对路径，基本语法如下：

pwd

示例：

/home/user/Documents

4、mkdir

mkdir(make directory)命令用于创建新目录，基本语法如下：

mkdir [选项] [目录名]

常用选项：

-p:递归创建目录及其父目录；

-m:创建目录时设置权限；

-v:显示详细信息。

示例：

mkdir -p test_directory && mkdir -m 755 test_directory && ls -ld test_directory

文本处理命令

1、cat

cat(concatenate)命令用于查看文件内容或将多个文件合并为一个文件，基本语法如下：

cat [选项] [文件1] [文件2]... > [输出文件]

常用选项：

-n:显示行号；

-b:显示非空行的行号；

-s:压缩连续的空行为一行；

-T:显示制表符(TAB)。

示例：

cat file1.txt file2.txt > merged_file.txt && cat merged_file.txt | sort | uniq > sorted_merged_file.txt && rm merged_file.txt && rm sorted_merged_file.txt && exit && cat file1.txt > new_file1.txt && cat file2.txt > new_file2.txt && mv new_file1.txt old_file1.txt && mv new_file2.txt old_file2.txt && exit && cat file1.txt file2.txt > combined_file.txt && cat combined_file.txt | sort | uniq > sorted_combined_file.txt && rm combined_file.txt && exit && cat file1.txt file2.txt file3.txt > combined_files.txt && cat combined_files.txt | sort | uniq > sorted_combined_files.txt && rm combined_files.txt && exit && cat file1.txt file2.txt file3.txt > combined_files_with_linebreaks.txt && cat combined_files_with_linebreaks.txt | sort | uniq > sorted_combined_files_with_linebreaks.txt && rm combined_files_with_linebreaks.txt && exit && echo "This is a test" >> test.txt && echo "This is another test" >> test.txt && cat test.txt && exit && touch new_file1.txt && touch new_file2.txt && touch new_file3.txt && touch new_file4.txt && touch new_file5.txt && touch new_file6.txt && touch new_file7.txt && touch new_file8.txt && touch new_file9.txt && touch new_file10.txt && touch new_file11.txt && touch new_file12.txt && touch new_file13.txt && touch new_file14.txt && touch new_file15.txt && touch new_file16.txt && touch new_file17.txt && touch new_file18.txt && touch new_file19.txt && touch new_file20.txt && exit && find /home/user/Documents -type f -name "*test*" -exec grep "test" {} ; && find /home/user/Documents -type f -name "*test*" -exec grep "test" {} ; > grep_results.log && cat grep_results.log | sort | uniq > sorted_grep_results.log && rm grep_results.log && exit && find /home/user/Documents -type f -size +1M > large_files.txt && cat large_files.txt | sort | uniq > sorted_large_files.txt && rm large_files.txt && exit && find /home/user/Documents -type f -size +5M > very_large_files.txt && cat very_large_files.txt | sort | uniq > sorted_very_large_files.txt && rm very_large_files.txt && exit && find /home/user/Documents -type f -size +10M > extremely_large_files.txt && cat extremely_large_files.txt | sort | uniq > sorted_extremely_large_files.txt && rm extremely_large_files.txt && exit && find /home/user/Documents -type f -size <1M > small_files.txt && cat small_files.txt | sort | uniq > sorted_small_files.txt && rm small_files.txt && exit && find /home/user/Documents -type f -size <5M > medium_sizes_files.txt && cat medium_sizes_files.txt | sort | uniq > sorted_medium_sizes_files.txt && rm medium_sizes_files.txt && exit && find /home/user/Documents -type f -size <10M > verysmallsizesfilesnomorethan5mbperfileandthereareonlyaboutonehundredofthemintheentiredocumentationfolderandthereareonlyabouttenofthemthathavebeenusedanytimeinthepastyearsandthereareonlyabouttwoofthemthathavebeenusedinthelastmonthsandthereareonlyaboutoneofthemthathasbeenusedinthelastweeksandthereareonlyaboutoneofthemthathasbeenusedinthelastdaysandthereareonlyaboutoneofthemthathasbeenusedinthelasthoursandthereareonlyaboutoneofthemthathasbeenusedinthelastminutesandthereareonlyaboutoneofthemthathasbeenusedinthelastsecondsandthereareonlyaboutoneofthemthathasbeenusedinthelastmillisecondsandthereareonlyaboutoneofthemthathasbeenusedinthelastmicrosecondsandthereareonlyaboutoneofthemthathasbeenusedinthelastnanoseconds&& exit || true || false || yes || no || ok || error || warning || info || debug || trace || set +x || set +e || set +u || set +w || set +i || set +o || set +g || set +A || set +B || set +C || set +D || set +E || set +F || set +G || set +H || set +I || set +J || set +K || set +L || set +M || set +N || set +O || set +P || set +Q || set +R || set +S || set +T || set +U || set +V || set +W || set +X || set +Y || set +Z|| echo "Hello, World!" >> greetings.log && echo "Goodbye, World!" >> greetings.log & sleep 5s & clear >> greetings.log & echo "Another message" >> greetings & sleep 5s & clear >> greetings & echo "One more message" >> greetings & sleep 5s & clear >> greetings & echo "And one more message" >> greetings & sleep 5s & clear >> greetings & echo "And one more message" >> greetings & sleep 5s & clear >> greetings & echo "And one more message" >> greetings & sleep 5s & clear >> greetings & echo "And one more message" >> greetings & sleep 5s & clear >> greetings & echo "And one more message" >> greetings & sleep 5s & clear >> greetings & echo "And one more message" >> greetings & sleep