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IntroductiontolinuxBog'liq introductiontolinux| 23
Piping output from one command into another is a very useful way of working at the command
prompt. It can allow you to output the results of a command into a file, or even allow you to search
through the output for a specific string. Let’s try looking for the same man pages again, but this time
we will redirect the output to the Linux search system ‘grep ’, and search for a specific line of text.
As you can see, now only a few results are displayed. Only the results from ‘man –k directory ’
containing that search string ‘ls ’ are displayed, and the lines not meeting the search criteria are
discarded.
Grep can be useful when searching through a long list of files/folders for one specific entry, or
when working with any large amounts of data. In this case, we simply used it to filter search results.
Using the command ‘man –k directory | grep ’, try searching for some other keywords,
replacing with the word of your choice. For example: run, NT, ACL, ln.
Need More Help?
If at any point you require more help than the ‘man’ pages can provide, there are a number of other
resources. One of these resources is ‘TLDP’ (The Linux Documentation Project). Not only does this
contain a copy of all the man pages, but there are Howto, guides, and FAQs on various Linux-related
subjects. Take a look at
http://www.tldp.org
in your own time.
By far, the best source of information for Linux is ‘Google’. If you are ever stuck, try Googling for
the solution. You will always feel a greater sense of accomplishment if you solve a problem yourself.
Never underestimate forums or newsgroups. While a solution may not immediately be apparent
(especially from the first few posts), the users that have posted will normally work toward a solution,
and the forum is a very good way of finding out what has worked and not worked previously.
When Googling, remember to put exactly what you’re looking for. It is recommended that you put
your linux distro into the search string, as some problems and solutions may be distro-specific.
Another key word to use is ‘howto ’. If you are looking for a guide, this can provide the best results.
Try it by Googling for; ‘linux dhcp howto ’ in your free time, and take a look at the results.
After (and only) after you have exhausted ALL other avenues for help, ask someone. People are more
willing to help if you have tried to solve things yourself.
REMEMBER:
Always try to help yourself first by researching the problem!
clear
man -k directory | grep ls
Clear all previous output
This pipes the output from the man-k
command into grep. In this instance,
we have told grep to search for the
string ‘ls’
NOTE:
Pipe (|) is not a capital ‘i’
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