To view a short file, we can simply use
cat, as we saw before. For viewing larger files with search and easy navigation options, we instead use
The main reason that one would want to use
more instead of a text editor like Vim is that these file readers don't have to load the entire file contents into memory.
more command is a very basic file read. We are only able to read files forward, so no backward movement is available.
To open a file with more, simply enter the filename as the argument.
$ more file1.txt
To see a list of controls when activating
more, simply press h.
Unix users like the old adage, "less is more," so they named an improved version of more as less.
less is an extension of
more. It provides backward movement in the file, along with forward movement. x
$ less file.txt
Here are some basic commands for less. Remember that you can simply press the h key to display a complete command summary.
To search forward or backward for the word "foo" in a file, you can type
?foo, respectively. You can then press
n to move forward in the search.
In case you want to read just the beggining or ends of a file, you may use the
tail commands, which output the first and last 10 lines by default. To specify a certain number of lines, use the
tail command is especially helpful when reading out log files, in which the most recent text is appended onto the end of the files.
$ tail -n 3 /var/log/wifi.log
Wed Jul 29 05:17:52.328 ***Starting Up*** Fri Aug 14 22:09:10.179 ***Starting Up*** Tue Sep 15 12:25:43.535 ***Starting Up***
You can even live-track the file with the
-f option (f for follow). With this option on, you may see any changes that are added to the file instantaneously.
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