We can read from files using the cat command and the output is written to STDOUT. We can also use a pipe and redirect output elsewhere
[glen.knight@expert-syn-srv-1 t1]$ cat f1
hello
We can count the number of lines in a file using the command wc -l
[glen.knight@expert-syn-srv-1 t1]$ wc -l /etc/services
11176 /etc/services
We can page through long files using the less command
[glen.knight@expert-syn-srv-1 t1]$ less !$**Note: the !$ command represents the last argument used, which in this case is the file /etc/services
We can use the head command to read the beginning of a file and tail to read the bottom of a file. We can use the -n switch to specify the number of lines we want to read.
[glen.knight@expert-syn-srv-1 t1]$ head -n 5 /etc/services
# /etc/services:
# $Id: services,v 1.55 2013/04/14 ovasik Exp $
#
# Network services, Internet style
# IANA services version: last updated 2013-04-10
[glen.knight@expert-syn-srv-1 t1]$ tail -n 5 /etc/services
com-bardac-dw 48556/tcp # com-bardac-dw
com-bardac-dw 48556/udp # com-bardac-dw
iqobject 48619/tcp # iqobject
iqobject 48619/udp # iqobject
matahari 49000/tcp # Matahari Broker