How to grep the logs between two date range in Unix - linux

Question

I have a log file abc.log in which each line is a date in date +%m%d%y format:
061019:12
062219:34
062319:56
062719:78
I want to see the all the logs between this date range (7 days before date to current date) i.e (from 062019 to 062719 in this case). The result should be:
062219:34
062319:56
062719:78
I have tried few things from my side to achieve:
awk '/062019/,/062719' abc.log
This gives me correct answer, but if i don't want to hard-code the date value and try achieving the same it does not give the correct value.
awk '/date --date "7 days ago" +%m%d%y/,/date +%m%d%y' abc.log
Note:
date --date "7 days ago" +%m%d%y → 062019 (7 days back date)
date +%m%d%y → 062719 (Current date)
Any suggestions how this can be achieved?

Answer 1

Your middle-endian date format is unfortunate for sorting and comparison purposes. Y-m-d would have been much easier.
Your approach using , ranges in awk requires exactly one log entry per day (and that the log entries are sorted chronologically).
I would use perl, e.g. something like:
perl -MPOSIX=strftime -ne '
BEGIN { ($start, $end) = map strftime("%y%m%d", localtime $_), time - 60 * 60 * 24 * 7, time }
print if /^(\d\d)(\d\d)(\d\d):/ && "$3$1$2" ge $start && "$3$1$2" le $end' abc.log
Use strftime "%y%m%d" to get the ends of the date range in big-endian format (which allows for lexicographical comparisons).
Use a regex to extract day/month/year from each line into separate variables.
Compare the rearranged date fields of the current line to the ends of the range to determine whether to print the line.

Answer 2

To get around the issue of looking for dates that may not be there, you could generate a pattern that matches any of the dates (since there are only 8 of them it doesn’t get too big, if you want to look for the last year it might not work as well):
for d in 7 6 5 4 3 2 1 0
do
pattern="${pattern:+${pattern}\\|}$(date --date "${d} days ago" +%m%d%y)"
done
grep "^\\(${pattern}\\)" abc.log