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Bash tricks

What is my bash​

echo "$SHELL" && ps -p $$

Manipulating a text file​

Below is a sample text file and following are common tasks performed on the file.

example.txt
admin.examplelike.com.red.
files.examplelike.com.red.
examplelike.com.red.
imports.examplelike.com.red.
vpn.examplelike.com.red.

Remove char "dot" at the end of line from file​

cat example.txt| sed 's/\.$//g'

Replace newline with comma​

cat example.txt| tr '\n' ', '

extract domains from zonetransfer for hosts file​

zonetransfer.txt
; <<>> DiG 9.18.11-2-Debian <<>> axfr @10.11.11.29 examplelike.com
; (1 server found)
;; global options: +cmd
examplelike.com.                604800  IN      SOA     localhost. root.localhost. 2 604800 86400 2419200 604800
examplelike.com.                604800  IN      AAAA    ::1
examplelike.com.                604800  IN      NS      localhost.
examplelike.com.                604800  IN      A       127.0.0.1
administrator1.examplelike.com. 604800 IN A     127.0.0.1
hr.examplelike.com.     604800  IN      A       127.0.0.1
uploads.examplelike.com.        604800  IN      A       127.0.0.1
examplelike.com.                604800  IN      SOA     localhost. root.localhost. 2 604800 86400 2419200 604800
;; Query time: 139 msec
;; SERVER: 10.11.11.29#53(10.11.11.29) (TCP)
;; WHEN: Mon Apr 17 08:09:05 EDT 2021
;; XFR size: 8 records (messages 1, bytes 289)
cat zonetransfer.txt | awk '/604800/ {print $1}' | sort -u | tr '\n' ' ' | sed 's/\. / /g'