Awk command examples

1. Listing all lines in a file
# awk '//{print}' filename

2. List lines with specific word from a file
# awk '/localhost/{print}' filename

3. Use of awk with (.) wild card
# awk 'l.c/{print}' filename

4. Use of awk with (*) wild card
# awk 'l*c/{print}' filename

5. Use of awk with a set of characters
# awk '/[ab9]/{print}' filename
# awk '/[pu]p/{print}' filename

6. Specifying numbers and characters in a range with awk
# awk '/[0-9]/{print}' filename
Similarly these can be used - [a-z][A-Z][a-zA-Z][a-zA-Z 0-9]

7. Use of Awk with meta character(^)
# awk '/^192/{print}' filename

8. Use of Awk with meta character ($)
# awk '/com$/{print}' filename

9. Use of Awk with escape character (/)
# awk '/\$/{print}' filename

10. Use of Awk to print the fields and columns.
# awk '//{print $1 $2 $3}' filename
# awk '//{print $1,$2,$3}' filename
# awk '//{printf "%-10s %s\n",$1,$2}' filename