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While researching an old install for an upgrade system requirement compliance, I discovered that I b=need to validate which Linux version was installed. So, here is a quick note on the command I used to validate which version of Linux was installed.
Despite the ‘man’ commands, relative simplicity and appearance of unimportance, the ‘man’ command is, perhaps, one of the most important commands to lean in Linux.
The true value of the ‘man’ command is that provides access to the online manuals (documentation), which will be consulted often until Linux commands and functions have to be learned and internalized. Even after learning the more familiar and commonly used Linux command and functions, one will still need to refer the less commonly used capabilities or to confirm something which has been used in a while.
When some the more arrogant Linux users will sometime tell folks with questions to “read the frickin’ manual” (RTFM), the ‘man’ command is what they are usually talking about. Although there are other perfectly useful reference materials online (e.g., git documentation project) or commercial books, the ‘man’ command should be the go-to place for documentation. The reason this is actually very simple, if the command or function is installed in your version or environment instance of Linux, then man pages will be available. Therefore, usually, there will no need to go search on the internet for answers or carrying books around.
The syntax of the ‘man’ command is simple and easy to learn to use. In fact, the ‘man’ command is so easy to use that people frequently will not even use options when they use the man command and enter ‘man’ command and the keyword.
man [options] (keywords)
Simple examples to illustrate how to use the ‘man’ command.
[blog-server ~]$ man man
In this example, the man command is using ‘man man’ to pull up its own online documentation.
[blog-server ~]$ man ls
In this example, the man command is using ‘man ls’ to pull up the ‘list directory contents‘ online documentation.
list directory contents
[blog-server ~]$ man cp
In this example, the man command is using ‘man cp’ to pull up the ‘copy files and directories ‘ online documentation.
To install the locate command (mlocate) in Redhat or Centos, use the ’YUM’ command, install function.
[root@blog-server ~]# man locate
[root@blog-server ~]# yum install mlocate
[root@blog-server ~]# sudo yum install mlocate
Then run the [root@data-server ~]# updated
[root@blog-server ~]# updated
[root@blog-server ~]# sudo updatedb
To quit the Linux ’vi’ editor without saving any changes which have been made:
: q!
This will quit the Linux VI editor, and all changes the document made in this session will be lost.
The Linux move command (mv) is one of the essential commands, which can be very useful in Linux, Unix, and AIX. The primary purpose of the move command is obviously to move files, and of course, directories. The move command may also be used to rename files and to make backups.
$ mv [options] source (file or directory) destination
| option | description |
| mv -f | force move by overwriting destination file without prompt |
| mv -i | interactive prompt before overwriting |
| mv -u | update – move when the source is newer than the destination |
| mv -v | verbose – print source and destination files |
| MV – t | explicitly saying to move the file or directory here, rather trying to fit everything into the last argument. |
| mv * | Move all (Multiple) files to a specific director without listing by name |
$ man mv
Here are some quick and very simple move command (MV) examples for reference.
$ mv happy.txt garden.txt /Archive/
$ mv *.txt backup
$ mv backup/*
$ mv happy.txt happy.bak
$ mv backup backup2
$ mv -u happy.txt backup
$ mv -v happy.txt backup
