Support for reading from stdin and dumping db to a file

[mcortizo]

If the only access you have to the log is via cat or tail from ssh connection, the script will need reading from stdin.
And maybe you want backup in a file the data you're printing.

[lebinh]

Thanks, reading from stdin is a really good idea but I don't think another parameter is needed. Maybe some thing like -l stdin is enough? I'd definitely merge that.
For db dump, the purpose of ngxtop is to enable a real-time understanding of what's happening with nginx, so I'm not sure a db dump would be needed here. Do you have any use case for that? Otherwise the changes to add that db dump functionality, which relied on a global variable and too tightly coupled with the SQLProcessor implementation, would make the code harder to change later on.

[mcortizo]

First, I agree with you about db dump; I had the idea but no use cases, and perhaps it is not the best way to do it...
About reading from stdin, I tried with the option-l stdin but I got an error: IOError: [Errno 2] No such file or directory: 'stdin' after trying to locate the nginx pid and config. It seems that the script looks for a file named 'stdin' instead of reading from stdin.
Also, this way you don't need to install nginx to analyze remote or local logs.

[lebinh]

Yup, what I mentioned is that it'd be great if we can use -l stdin instead of another option, like -s in your pull request. So if you can modify your commit, I'd gladly merge it :)

[mcortizo]

Thanks, I've removed the -s option and it is not necessary to specify an option, as the script detects the redirection as a non-tty input :)

[halcolm]

great addition! 👍

[LaiJingli]

Hi,good job.
but when i try to analyze remote nginx access log,for example "ssh 192.168.0.110 tail -f /var/log/nginx/hog-access.log | ngxtop" ,i have also make ssh no password login works first,but it's report:"Error: access log file "stdin" does not exist",it's like the pipe done'nt work? my ngxtop is the newest.

[lebinh]

Silly me, pushed the fix for that. Can you try it again with latest commit?

[LaiJingli]

hei,lebinh
the remote analyze has fixed with your recommit,thks for your fast reponse! but when run a few seconds later ,it will stop to work and report an error as follow ( like this issue #23):
"Traceback (most recent call last):
File "/usr/local/bin/ngxtop", line 11, in
sys.exit(main())
File "build/bdist.linux-x86_64/egg/ngxtop/ngxtop.py", line 495, in main
File "build/bdist.linux-x86_64/egg/ngxtop/ngxtop.py", line 463, in process
File "build/bdist.linux-x86_64/egg/ngxtop/ngxtop.py", line 357, in process_log
File "build/bdist.linux-x86_64/egg/ngxtop/ngxtop.py", line 305, in process
sqlite3.ProgrammingError: library routine called out of sequence"