用户管理命令
* useradd root, the function is to add a new user, the syntax is useradd [user name]
* password, all users have permissions, the function is to modify user password
* who all users have permissions, the function is to look up the logged-in user information -w more detailed
文件压缩解压命令
* gzip (gunzip) all users can perform the function of compression (decompression), the syntax gzip (gunzip) [file name]
gzip -d = gunzip, this command can only compress files, and does not save the source file. After compression * .gz
* tar All users have permissions, the function is the packaging directory, the syntax tar [option] [compressed file name] [directory]
option -c packaging, -v display detailed information, -f specifies the file name, -zc packaging and compression -x unpack, and -zx unpack at the same time unzip the file. After compression * .tar.gz -f must be placed at the end. Generate .bz2 needs to replace z with j
zip All users have permissions, the function is to compress files or directories, the syntax is zip [-r] [compressed file name] []
[file or directory], -r compressed directory. After compression: .zip unzip to decompress.
bzip2 All users have permissions, the function is to compress files, the syntax is: bzip2 [-k] [file], -k keep the source file after generating the compressed file, after compression: .bz2, decompress bunzip2
