Documentations and Tools Installed Help Documentations Because of the changes in the LFCS exam targets powerful February 2nd,
2016, we are adding the needed topics to the LFCS collection published here.
To put together for this examination, your are rather recommended to use the LFCE collection as properly.
Documentations and Tools Once you get used to working with the command line and feel comfortable doing so,
you recognize that a regular Linux set up consists of all the documentation you need to apply and configure the machine.
Another precise purpose to become familiar with command line assist gear is that in the LFCS and LFCE exams,
those are the most effective assets of information you may use – no internet browsing and no googling. It’s simply you and the command line.
For that motive, in this article we are able to come up with some pointers to efficiently use the hooked up docs,
equipment with the intention to put together to skip the Linux Foundation Certification assessments.
Documentations and Tools Installed Help Documentations Linux Man Pages
Documentations and Tools A man page, brief for guide web page, is not anything much less and nothing extra than what the word shows: a guide for a given tool.
It consists of the list of alternatives (with rationalization) that the command helps, and a few man pages even encompass usage examples as properly.
To open a man page,
use the person command accompanied with the aid of the call of the tool you need to study greater about. For instance:
# man diffwill open the manual page for diff, a tool used to compare text files line by line (to exit, simply hit the q key.).
Let’s say we want to compare two text files named file1 and file2 in Linux. These files contain the list of packages that are installed in two Linux boxes with the same distribution and version.
Doing a diff between file1 and file2 will tell us if there is a difference between those lists:
# diff file1 file2
where the < sign indicates lines missing in file2. If there were lines missing in file1, they would be indicated by the > sign instead.
On the other hand, 7d6 means line #7 in file should be deleted in order to match file2 (same with 24d22 and 41d38), and 65,67d61 tells us we need to remove lines 65 through 67 in file one. If we make these corrections, both files will then be identical.
Alternatively, you can display both files side by side using the -y option, according to the man page. You may find this helpful to more easily identify missing lines in files:
# diff -y file1 file2
Also, you may use diff to examine two binary files. If they may be same, diff will exit silently with out output. Otherwise, it’s going to go back the following message: “Binary files X and Y vary”.
Installed Help Documentations The –help Option
The –assist option, to be had in lots of (if no longer all) instructions, may be considered a short manual page for that specific command.
Although it does now not provide a comprehensive description of the tool, it’s far an clean manner to acquire information on the usage of a software and a list of its to be had options at a short glance.
For instance,
# sed --helpSuggests the usage of every choice available in sed (the movement editor).
One of the conventional examples of the use of sed includes changing characters in documents. Using the -i alternative (described as “edit files in area”), you may edit a report without opening it.
If you need to make a backup of the authentic contents as nicely, use the -i choice observed by means of a SUFFIX to create a separate file with the authentic contents.
For instance, to update every prevalence of the phrase Lorem with Tecmint (case insensitive) in lorem.
Txt and create a new document with the original contents of the file, do:
Please note that every occurrence of Lorem has been replaced with Tecmint in lorem.txt, and the original contents of lorem.txt has been saved to lorem.txt.orig.
