Welcome to the staging ground for new communities! Each proposal has a description in the "Descriptions" category and a body of questions and answers in "Incubator Q&A". You can ask questions (and get answers, we hope!) right away, and start new proposals.

Are you here to participate in a specific proposal? Click on the proposal tag (with the dark outline) to see only posts about that proposal and not all of the others that are in progress. Tags are at the bottom of each post.

Review Suggested Edit

You can't approve or reject suggested edits because you haven't yet earned the Edit Posts ability.

I'm sure there's a program somewhere that parses syslog entries, but I don't know what it is (well, there's journald but I find that very arcane). However, the task as stated is pretty simple so I'd try hack something together myself. You need to:
1. Pull out the error code and referrer with a regex
2. Filter for 404 codes
3. Filter out empty referrers
4. Print requests
5. Count them
1 can be done with a regex and `sed`, but you need a lot of `[]{}()+` in the pattern, and sed makes these annoying to type (you have to escape them all). So instead I would read into a Python script.
If you use sed for 1, you would use grep for 2 and 3, also with regex.
If you want to stick with the shell, you can use Python to only dump a JSON, CSV, or whatever else you want. You can filter JSON with `jq` and CSV with `csvkit` or `csvq`.
Since I used Python, it's easier to use Python's syntax for filtering as well, which is what I did:
```python
import re
import sys
from collections import Counter
from typing import NamedTuple
RE_SYSLOG = re.compile(r'(?:\S+ ){3}\[([^[\]]+)\] "([^"]+)" (\d+) \S+ "([^"]+)"')
class LogEntry(NamedTuple):
timestamp: str
request: str
error_code: str
referer: str
def main():
raw = sys.stdin.readlines()
parsed = [parse_syslog_message(s) for s in raw]
filtered = [i for i in parsed if i.error_code == "404" and len(i.referer) > 3]
# Print requests
for i in filtered:
print(i.request)
def parse_syslog_message(msg: str) -> LogEntry:
m = RE_SYSLOG.search(msg)
return LogEntry(*m.groups())
if __name__ == "__main__":
main()
```
You then do `cat web.log | python parse.py` and you'll get a list of the requests you want (4). I assumed you do care about request type (because it's easier that way) but I'm sure you can see how to get only the URL from `i.request`.
What remains is to count. You can do this with `uniq` (which requires pre-sorted input):
```
cat web.log | python parse.py | sort | uniq -c
1 GET http://example.com/some-page.html HTTP/1.1
```

I'm sure there's a program somewhere that parses common log entries, but I don't know what it is. However, the task as stated is pretty simple so I'd try hack something together myself. You need to:
1. Pull out the error code and referrer with a regex
2. Filter for 404 codes
3. Filter out empty referrers
4. Print requests
5. Count them
1 can be done with a regex and `sed`, but you need a lot of `[]{}()+` in the pattern, and sed makes these annoying to type (you have to escape them all). So instead I would read into a Python script.
If you use sed for 1, you would use grep for 2 and 3, also with regex.
If you want to stick with the shell, you can use Python to only dump a JSON, CSV, or whatever else you want. You can filter JSON with `jq` and CSV with `csvkit` or `csvq`.
Since I used Python, it's easier to use Python's syntax for filtering as well, which is what I did:
```python
import re
import sys
from collections import Counter
from typing import NamedTuple
RE_SYSLOG = re.compile(r'(?:\S+ ){3}\[([^[\]]+)\] "([^"]+)" (\d+) \S+ "([^"]+)"')
class LogEntry(NamedTuple):
timestamp: str
request: str
error_code: str
referer: str
def main():
raw = sys.stdin.readlines()
parsed = [parse_syslog_message(s) for s in raw]
filtered = [i for i in parsed if i.error_code == "404" and len(i.referer) > 3]
# Print requests
for i in filtered:
print(i.request)
def parse_syslog_message(msg: str) -> LogEntry:
m = RE_SYSLOG.search(msg)
return LogEntry(*m.groups())
if __name__ == "__main__":
main()
```
You then do `cat web.log | python parse.py` and you'll get a list of the requests you want (4). I assumed you do care about request type (because it's easier that way) but I'm sure you can see how to get only the URL from `i.request`.
What remains is to count. You can do this with `uniq` (which requires pre-sorted input):
```
cat web.log | python parse.py | sort | uniq -c
1 GET http://example.com/some-page.html HTTP/1.1
```

Communities

Review Suggested Edit