awk

 

$ awk –F'[ :\t]'  '{print $1, $2, $3}' people.txt

----------------------------			

$ awk '{print NR, $1, $2, $4}' people.txt

					
The output will be:

					
1 Bill Thomas 08/9/1968
2 Fred Martin 22/7/1982
3 Julie Moore 25/2/1978
4 Marie Jones 05/8/1972
5 Tom Walker  14/1/1977

----------------------------		
$ cat people.txt | awk '$3 > 6500 {print $1, $2}'

-------------
					
Bill Thomas  8000  08/9/1968
Fred Martin  6500  22/7/1982
Julie Moore  4500  25/2/1978
Marie Jones  6000  05/8/1972
Tom Walker   7000  14/1/1977
$ awk '{					
if ($3 > 7000) { print "person with salary more than 7000 is \n", $1, " "
, $2;}					
}' people.txt

					
The output is as follows:

					
person with salary more than 7000 is
Bill Thomas

				
===========================

An example of the awk command with the for loop is as follows:

$ awk '{ for( i = 1; i <= NF; i++) print NF, $i }' people.txt

---------------------------------------------------
$ cat people.txt

					
$ awk '{ i  = 1; while ( i <= NF ) { print NF, $i ; i++ } }' people.txt
=============================
$ cat awk_script
BEGIN {				
do {
++x				
    print x
  } while ( x <= 4 )					
}
$ awk -f awk_script
			
================================