Display the first few lines of a file in Unix
Use the Unix head
command to read the first
few lines of an input file and send them to standard output (that is,
your terminal screen). The format for the head
command
is:
head -lines filename
In this example, lines
is an optional value specifying
the number of lines to be read. If you don't give a number, the
default value of 10 is used. Also, filename
represents
the name of an optional file for the head
command to
read. Otherwise, it will take its input from stdin (standard input:
the terminal, or whatever the shell feeds the process with,
usually pipe output).
For example, given a file containing the English alphabet with each letter on a separate line, a user enters the command:
head -3 alphabetfile
This command would return:
a b c
You can also use the head
command with pipes. For example, to see
the sizes of the first few files in a large directory, you could enter
at the Unix prompt:
ls -l | head
To save this information into a file in the current directory named
mylist
, you could enter:
ls -l | head > mylist
For more information, consult the Unix manual page by entering at the Unix prompt:
man head
At Indiana University, for personal or departmental Linux or Unix systems support, see Get help for Linux or Unix at IU.
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Last modified on 2019-08-27 08:51:49.