Routine Linux management and maintenance-software management

Daily Linux Management and Maintenance & mdash; software management I. introduction based on our operating system experience, we use the operating system to actually use the application software running on the operating system, and use the software to help us complete various types of work; before that, we only used linux systems... routine management and maintenance of Linux-software management I. introduction based on our experience in operating systems, we actually use more applications running on the operating system, using these software to help us complete various types of work, we previously only performed a large number of user and file directory operations in the linux system, and did not use its software features. In the previous operations on the character interface, we found that Chinese characters cannot be displayed and used in the environment. if you want to use Chinese characters, you need to install the Chinese environment, that is, using the software, so today, we will tell you how to install and use software in linux. In addition, we often install software in windows. we know that many software is compressed before installation, it must be decompressed before installation. Therefore, we need to know how to compress and decompress files in linux. Today, our main content is the application and software management of compressed files, which is also a very important operation in system applications. we must master it, so it is also the focus of this lesson. Next, let's take a look at the management of compressed files in linux. II. compressed file management: 1. use and technology of compressed files in Linux: technology that releases unused space in files to reduce the space occupied by Files. Benefits of compression: the compressed file capacity becomes smaller, the hard disk can accommodate more data, and can improve the file transmission speed; compression ratio: the percentage of disk space occupied by the files before compression and after compression. 2. common compressed file extensions: Windows :*. zip ,*. rar Linux :*. z: files compressed by the compress program, in the early format ;*. bz2: files compressed by bzip2 program ;*. gz: The file compressed by the gzip program ;*. tar: The data packaged by the tar program is not compressed; * .tar.gz: The files packaged by the tar program are compressed by gzip; 3. compression Command: (1) compress: compress syntax: compress [-dcr] file or directory function: simple compression of files or directories, compression extension *. z; parameter meaning:-d: used for decompression;-r: can be compressed together with files in the directory;-c: outputs compressed data as standard output (screen output ); example: Example 1: compress the file aa in the main directory [root @ linux ~] # Ls aa [root @ linux ~] # Compress aa [root @ linux ~] # Ls-l-rw-r -- 1 root 1024 Mar 25 :10 aa. Z Example 2: decompress aa. Z [root @ linux ~] # Ls aa. Z [root @ linux ~] # Compress-d aa. Z [root @ linux ~] # Ls aa Example 3: compress aa into another file [root @ linux ~] # Ls aa [root @ linux ~] # Compress-c aa> bb. Z [root @ linux ~] # Ls aa bb. z uncompress syntax: uncompress file name function: used to extract. Z file data content t; example: uncompress aa. *. decompress the Z File. it indicates the parameter meaning:-d: used for decompression;-t: can be used to check the consistency of a compressed file to see whether the file is correct;-c: output the compressed data to the standard output (screen output).-#: compression level.-1 is the fastest, the compression ratio is the worst,-9 is the slowest, and the compression ratio is the best. the default value is-6. Example: Example 1: compress the file aa in the main directory [root @ linux ~] # Ls aa [root @ linux ~] # Gzip aa [root @ linux ~] # Ls aa.gz Example 2: decompress aa.gz [root @ linux ~] # Gzip-d aa.gz Example 3: Use the best compression ratio to compress aa and keep the original file [root @ linux ~] # Gzip-9-c aa> bb.gz gunzip syntax: gunzip file name function: Use to decompress .gz file data content t; example: gunzip aa.gz zcat syntax: zcat file name function: used to read compressed file data content, similar to cat. example: Read the aa.gz [root @ linux ~] file in the main directory. # Zcat aa.gz (3) bzip2 and bzcat bzip2 syntax: bzip2 [-cdz] file name function: compress the file into a compressed file, and extend the file name to .bz2 after compression. you can also perform *. decompress the Z File. it indicates the parameter meaning:-d: used for decompression;-c: outputs compressed data as standard output (screen output);-#: compression level,-1 is the fastest, the compression ratio is the worst,-9 is the slowest, and the compression ratio is the best. the default value is-6. Example: Example 1: compress the file aa in the main directory [root @ linux ~] # Ls aa [root @ linux ~] # Bzip2 aa [root @ linux ~] # Ls aa.bz2 Example 2: decompress aa.gz [root @ linux ~] # Bzip2-d aa.bz2 Example 3: compress aa with the best compression ratio and keep the original file [root @ linux ~] # Bzip2-9-c aa> bb.bz2