Using grep to display lines around the match also

 Example:

>grep -i  -C 2 "Module: my_program" report20201129*

In this case, we want to display the line above the ones that matches the pattern, since it contains important info.

Having fun with "for" loops in Linux

  >for i in {1..61}

> do

> for j in {01..12}

> do

> echo "create synonym us$i$j for usage_dummy;" >> 1.sql

> echo "create synonym au$i$j for accumulates_usage_dummy;" >> 1.sql

> done

> done

How to find special characters in the DB

  Match nth character

SQL> select case when regexp_like('ter*minator' ,'^...[^[:alnum:]]') then 'Match Found' else 'No Match Found' end as output from dual;

Output: Match Found

In the above example we tried to search for a special character at the 4th position of the input string “ter*minator”

Let’s now try to understand the pattern '^...[^[:alnum:]]'

^ marks the start of the string
. a dot signifies any character (… 3 dots specify any three characters)
[^[:alnum:]] Non alpha-numeric characters (^ inside brackets specifies negation)

Note: The $ is missing in the pattern. It’s because we are not concerned beyond the 4^th character and hence we need not mark the end of the string. (...[^[:alnum:]]$ would mean any three characters followed by a special character and no characters beyond the special character)

https://www.orafaq.com/node/2404

How to zip/unzip files on the fly, when we have space constraints

 To unpack on the fly:

gunzip < FILE.tar.gz | tar xvf -

To pack on the fly:
tar cvf - FILE-LIST | gzip -c > FILE.tar.gz

Another method, without creating a tar on the local server at all:

server1> tar cvf - 19.3.0 | ssh oracle@server2 "tar xvf - -C /u01/app/oracle/product"