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
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 ‘man’ command important?
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
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’ command syntax
man [options] (keywords)
Simple examples to illustrate how to use the ‘man’ command.
Example to pull up the
‘Man’ command documentation
[blog-server ~]$ man man
In this example, the man command is using ‘man man’ to pull up its own online
Example to pull up the
‘ls’ command 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
Example to pull up
the ‘cp’ command documentation
[blog-server ~]$ man cp
In this example, the man command is using ‘man cp’ to pull up the ‘copy files and
directories ‘ online documentation.
Example screenshot of
the ‘cp’ (copy files and directories) file command online documentation
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
Move Command options
force move by overwriting destination file
interactive prompt before overwriting
update – move when the source is newer than the
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.
Move all (Multiple) files to a specific director without
listing by name
For More move command
details see the Linux documentation manuals using the man command
$ man mv
Here are some quick and very simple move command (MV)
examples for reference.
Move Move to
files to the /Archive/ directory:
$ mv happy.txt garden.txt /Archive/
Move all “.txt” files
in the current directory to subdirectory backup:
$ mv *.txt backup
Move all files in
subdirectory ‘backup’ to current directory:
$ mv backup/*
Rename file happy.txt
to happy.bak filename:
$ mv happy.txt happy.bak
Rename directory backup
$ mv backup backup2
Update – move when happy.txt
is newer or missing in target directory:
$ mv -u happy.txt backup
Move happy.txt and
prompt before overwrite backup / happy.txt:
Many of us either want a way to import our Linux knowledge,
improve our technical career options or perhaps, move into the technology
career. To do any of these efficiently
them, the first step would be to focus on the major Linux distribution used by
The most adapted distributions Linux are Red Hat Enterprise
Linux (RHEL) and Ubuntu, so, of the multitude of Linux distributions available,
these would be the to learn if you want to move your career forward.
However, if you are seeking an inexpensive alternative to hone your Linux skills at home, then CentOS, is likely your best choice since it is free and is pretty much a copy of RedHat.
In simple terms, yum is a, command-line interface, package manager utility for computers running the Linux operating system, which augments the RPM Package Manager capabilities. yum is the primary tool for getting, installing, deleting, querying, and managing RPM software packages. Also, yum is used in Red Hat Enterprise Linux (RHEL) versions 5 and later.