AWK Showing Output

Question 1

How do you display AWK output?

Answer 1

Using print
or
printf

Question 2

Whats the diff between print and printf?

Answer 2

both will print the output, but printf will also do some formatting.

For example, it can show a textual string and format it into a column of a specific size.
It can even strip decimals from floating numbers

Question 3

How do you search for a pattern using AWK?

Answer 3

awk /[pattern]/
where [pattern] is what you’re searching for.

the more complicated way to write it out is:
awk ‘($1 ~ /^(pattern1|pattern2)/) {print $2}’ filename

Where $1 first field is checked against pattern1 or pattern2 and it will print out the next field ($2) from the selected filename
likely a csv would fit this usecase well

Question 4

How would you print the Enviornment variables from a user?
Specifically, show the username stored in USER using AWK

Answer 4

awk ‘BEGIN { print ENVIRON[“USER”] }’

Question 5

How would you determine other environment variables?

Answer 5

See the export command for other environment variables that may be available

Question 6

What would this output?
~~~
awk -F: ‘BEGIN {
printf “%-20s %s\n”, “Username”, “Home directory”
printf “%-20s %s\n”, “——–”,”————–”}
{ printf “%-20s %s\n”, $1, $(NF-1) }
‘ /etc/passwd
~~~

Answer 6

output:
~~~
Username Home directory
——– ————–
root /root
daemon /usr/sbin
bin /bin
~~~