Need to check date format yyyymm

Shell Programming and Scripting
1

My source file having one date column. The formate of the date column is yyyymm. I need to validate whether all the rows are in same format in the given file. If it is not I have captured that records in a separate file. I am very new to Unix. I don't how to achieve this. Plz help me to achieve this

2

first convert the date to the required date format using to_char and specifying the date format u need.. then validate your input using the check constraints.. c if this helps.. even i am new to unix

3

Try:

grep -E -v '[0-9]{6}' file > newfile

egrep -v '[0-9]{6}' file > newfile

or:

awk '!/[0-9]{6}/' file > newfile