使用正则表达式解析 Bash 脚本中的 ClamAV 日志以插入 MySQL

Question

Morning/Evening all,

I've got a problem where I'm making a script for work that uses ClamAV to scan for malware, and then place it's results in MySQL by taking the resultant ClamAV logs using grep with awk to convert the right parts of the log to a variable. The problem I have is that whilst I have done the summary ok, the syntax of detections makes it slightly more difficult. I'm no expert at regex by all means and this is a bit of a learning experience, so there is probably a far better way of doing it than I have!

The lines I'm trying to parse looks like these:

/net/nas/vol0/home/recep/SG4rt.exe: Worm.SomeFool.P FOUND
/net/nas/vol0/home/recep/SG4rt.exe: moved to '/srv/clamav/quarantine/SG4rt.exe'

As far as I was able to establish, I need a positive lookbehind to match what happens after and before the colon, without actually matching the colon or the space after it, and I can't see a clear way of doing it from RegExr without it thinking I'm trying to look for two colons. To make matters worse, we sometimes get these too...

WARNING: Can't open file /net/nas/vol0/home/laser/samples/sample1.avi: Permission denied

The end result is that I can build a MySQL query that inserts the path, malware found and where it was moved to or if there was an error then the path, then the error encountered so as to convert each element to a variable contents in a while statement.

I've done the scan summary as follows:

Summary looks like:

----------- SCAN SUMMARY -----------
Known viruses: 329
Engine version: 0.97.1
Scanned directories: 17350
Scanned files: 50342
Infected files: 3
Total errors: 1
Data scanned: 15551.73 MB
Data read: 16382.67 MB (ratio 0.95:1)
Time: 3765.236 sec (62 m 45 s)

Parsing like this:

SCANNED_DIRS=$(cat /srv/clamav/$IY-scan-$LOGTIME.log | grep "Scanned directories" | awk '{gsub("Scanned directories: ", "");print}')
SCANNED_FILES=$(cat /srv/clamav/$IY-scan-$LOGTIME.log | grep "Scanned files" | awk '{gsub("Scanned files: ", "");print}')
INFECTED=$(cat /srv/clamav/$IY-scan-$LOGTIME.log | grep "Infected files" | awk '{gsub("Infected files: ", "");print}')
DATA_SCANNED=$(cat /srv/clamav/$IY-scan-$LOGTIME.log | grep "Data scanned" | awk '{gsub("Data scanned: ", "");print}')
DATA_READ=$(cat /srv/clamav/$IY-scan-$LOGTIME.log | grep "Data read" | awk '{gsub("Data read: ", "");print}')
TIME_TAKEN=$(cat /srv/clamav/$IY-scan-$LOGTIME.log | grep "Time" | awk '{gsub("Time: ", "");print}')
END_TIME=$(date +%s)
mysql -u scanner_parser --password=removed sc_live -e "INSERT INTO bs.live.bs_jobstat VALUES (NULL, '$CURRTIME', '$PID', '$IY', '$SCANNED_DIRS', '$SCANNED_FILES', '$INFECTED', '$DATA_SCANNED', '$DATA_READ', '$TIME_TAKEN', '$END_TIME');"
rm -f /srv/clamav/$IY-scan-$LOGTIME.log

Some of those variables are from other parts of the script and can be ignored. The reason I'm doing this is to save logfile clutter and have a simple web based overview of the status of the system.

Any clues? Am I going about all this the wrong way? Thanks for help in advance, I do appreciate it!

Answer 1

From what I can determine from the question, it seems like you are asking how to distinguish the lines you want from the logger lines that start with WARNING, ERROR, INFO.

You can do this without getting to fancy with lookahead or lookbehind. Just grep for lines beginning with

"/net/nas/vol0/home/recep/SG4rt.exe: "

then using awk you can extract the remainder of the line. Or you can gsub the prefix out like you are doing in the summary processing section.

As far as the question about processing the summary goes, what strikes me most is that you are processing the entire file multiple times, each time pulling out one kind of line. For tasks like this, I would use Perl, Ruby, or Python and make one pass through the file, collecting the pieces of each line after the colon, storing them in regular programming language variables (not env variables), and forming the MySQL insert string using interpolation.

Bash is great for some things but IMHO you are justified in using a more general scripting language (Perl, Python, Ruby come to mind).