2 Minute Guide to awk.

awk-primer.sh

awk '{ print $1 }' file.txt                               # Print column one from each line in file.txt
cat file.txt | awk '{print $2}'                           # Print column two from each line of piped input.
awk '{ print $3 $5 $NF }' file.txt                        # Print columns 3 & 5 and number of colums/fields on each line of file.txt.
awk 'BEGIN{ s=0 } { s+= $3 } END{ print s }' file.txt     # Sum up column 3 and print at the end of input (BEGIN=pre input, END=EOF)
awk 'BEGIN{n=0}{n+=$NF}END{print n/$NR}' file.txt         # Print the average number of of fields per record in file.txt
awk '/foo/' file.txt                                      # Print lines that contain 'foo' in file.txt
awk '/foo/{print $0}' file.txt                            # Print all records on lines that contain 'foo' in file.txt    
awk '/foo/{print $2}' file.txt                            # Print column 2 from all lines that contain 'foo' in file.txt
awk '$2=="foo"{print $1}' file.txt                        # Print column 1 from all lines that contain 'foo' in column $2 in file.txt
awk -F\; '{print $5}' file.txt                            # Print column 5 from all lines in file.txt DELIMITED by semicolon(;) [ie. CSV]