Question

I’m using an RPM-based distro and I want to dynamically search a log file for today’s date and yesterday’s date to output a report. The string has to be dynamic ( no egrep “\b2012-10-[20-30]\b” ) meaning that I can take the same one-liner or script and search a file for today’s date and yesterday’s date and print some output. Basically searching log files for specific entries.

Here’s what I got, but I want to replace the egrep with something dynamic:

grep "No Such User Here" /var/log/maillog | egrep "\b2012-10-2[3-4]\b" | cut -d "<" -f 3 | egrep -o '\b[a-zA-Z0-9._%-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}\b' | cut -d "@" -f 2 | sort -d |uniq -ci | awk -F" " '{ print "Domain: " $2 " has been sent " $1 " messages that got a No Such User Here error." }'

Any help is appreciated. I’m looking for something that very likely uses the date command

date "+%Y-%m-%d"

but I need to take the %d and search for both the current day, and yesterday. Can this be done?

Any insight is much appreciated.

Answer 1

If you have GNU date:

$ x=$(date "+%Y-%m-%d")
$ y=$(date "+%Y-%m-%d" -d "-1 day")
$ egrep "($x|$y)" file

x contains current date and y contains the yesterday’s date.