Grepping two patterns from event logs - regex

Question

I am seeking to extract timestamps and ip addresses out of log entries containing a varying amount of information. The basic structure of a log entry is:
<timestamp>, <token_1>, <token_2>, ... ,<token_n>, <ip_address> <token_n+2>, <token_n+3>, ... ,<token_n+m>,-
The number of tokens n between the timestamp and ip address varies considerably.
I have been studying regular expressions and am able to grep timestamps as follows:
grep -o "[0-9]\{4\}-[0-9]\{2\}-[0-9]\{2\}T[0-9]\{2\}:[0-9]\{2\}:[0-9]\{2\}"
And ip addresses:
grep -Eo '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'
But I have not been able to grep both patterns out of log entries which contain both. Every log entry contains a timestamp, but not every entry contains an ip address.
Input:
2021-04-02T09:06:44.248878+00:00,Creation Time,EVT,WinEVTX,[4624 / 0x1210] Source Name: Microsoft-Windows-Security-Auditing Message string: An account was successfully logged on.\n\nSubject:\n\tSecurity ID:\t\tS-1-5-18\n\tAccount Name:\t\tREDACTED$\n\tAccount Domain:\t\tREDACTED\n\tLogon ID:\t\tREDACTED\n\nLogon Type:\t\t\t10\n\nNew Logon:\n\tSecurity ID:\t\tREDACTED\n\tAccount Name:\t\tREDACTED\n\tAccount Domain:\t\tREDACTED\n\tLogon ID:\t\REDACTED\n\tLogon GUID:\t\tREDACTED\n\nProcess Information:\n\tProcess ID:\t\tREDACTED\n\tProcess Name:\t\tC:\Windows\System32\winlogon.exe\n\nNetwork Information:\n\tWorkstation:\tREDACTED\n\tSource Network Address:\t255.255.255.255\n\tSource Port:\t\t0\n\nDetailed Authentication Information:\n\tLogon Process:\t\tUser32 \n\tAuthentication Package:\tNegotiate\n\tTransited Services:\t-\n\tPackage Name (NTLM only):\t-\n\tKey Length:\t\t0\n\nThis event is generated when a logon session is created. It is generated on the computer that was accessed.\n\nThe subject fields indicate the account on the local system which requested the logon. This is most commonly a service such as the Server service or a local process such as Winlogon.exe or Services.exe.\n\nThe logon type field indicates the kind of logon that occurred. The most common types are 2 (interactive) and 3 (network).\n\nThe New Logon fields indicate the account for whom the new logon was created i.e. the account that was logged on.\n\nThe network fields indicate where a remote logon request originated. Workstation name is not always available and may be left blank in some cases.\n\nThe authentication information fields provide detailed information about this specific logon request.\n\t- Logon GUID is a unique identifier that can be used to correlate this event with a KDC event.\n\t- Transited services indicate which intermediate services have participated in this logon request.\n\t- Package name indicates which sub-protocol was used among the NTLM protocols.\n\t- Key length indicates the length of the generated session key. This will be 0 if no session key was requested. Strings: ['S-1-5-18' 'DEVICE_NAME$' 'NETWORK' 'REDACTED' 'REDACTED' 'USERNAME' 'WORKSTATION' 'REDACTED' '10' 'User32 ' 'Negotiate' 'REDACTED' '{REDACTED}' '-' '-' '0' 'REDACTED' 'C:\\Windows\\System32\\winlogon.exe' '255.255.255.255' '0' '%%1833'] Computer Name: REDACTED Record Number: 1068355 Event Level: 0,winevtx,OS:REDACTED,-
Desired Output:
2021-04-02T09:06:44, 255.255.255.255

Answer 1

$ sed -En 's/.*([0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}).*[^0-9]([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}).*/\1, \2/p' file
2021-04-02T09:06:44, 255.255.255.255
Your regexps can be reduced by removing some of the explicit repetition though:
$ sed -En 's/.*([0-9]{4}(-[0-9]{2}){2}T([0-9]{2}:){2}[0-9]{2}).*[^0-9](([0-9]{1,3}\.){3}[0-9]{1,3}).*/\1, \4/p' file
2021-04-02T09:06:44, 255.255.255.255
It could be simpler still if all of the lines in your log file start with a timestamp:
$ sed -En 's/([^,.]+).*[^0-9](([0-9]{1,3}\.){3}[0-9]{1,3}).*/\1, \2/p' file
2021-04-02T09:06:44, 255.255.255.255

Answer 2

If you are looking for lines that contain both patterns, it may be easiest to do it two separate searches.
If you're searching your log file for lines that contain both "dog" and "cat", it's usually easiest to do this:
grep dog filename.txt | grep cat
The grep dog will find all lines in the file that match "dog", and then the grep cat will search all those lines for "cat".

Answer 3

You seem not to know the meaning of the "-o" switch.
Regular "grep" (without "-o") means: give the entire line where the pattern can be found. Adding "-o" means: only show the pattern.
Combining two "grep" in a logical AND-clause can be done using a pipe "|", so you can do this:
grep <pattern1> <filename> | grep <pattern2>