head (Unix)
Head (English " head") is a program for Unix and Unix- like operating systems for the first several lines of a file. However, unlike a text editor, the user is not making changes to the file in the location with head. The counterpart of head is tail, which displays the last lines of a file.
Operation
The syntax of head resembles many other command-line programs:
Head [ switch ]
Normally head the first 10 rows are from a file. The switches can type (rows, bytes) and number of output can be selected.
Typical application examples
The following example returns the first 20 rows of
Head-n 20
Head- c 15 foo * Exotic examples
Many earlier versions of Unix did not have the command, therefore, referred the documentation and books on sed:
Sed 5q foo Some Unix systems still use the old syntax. There, the -n option is not supported. Here, the following syntax must be used for the first 20 rows, or output the first 50 bytes.
Head -20