LogReader
Reading lines in the text file which is growing and may be rotated, such as unix system log file.
- When the current file reaches EOF, this will wait new line added to the file. (like
tail -f
command) - Even when the current file is rotated, this will trace new file and continue reading lines.
Installation
Add this to your application's shard.yml
:
dependencies:
logreader:
github: arcage/crystal-logreader
Usage
require "logreader"
# create LogReader object
log = LogReader.new("/var/log/maillog")
# reads single line from the file
# waits new line, when the file reaches EOF
puts log.read_line
# iterates each line in the file
log.each do |line|
puts line
end
LogReader
has only two public instance method #read_line
and #each
#each
will not finish in normal operation. if you want to stop it, you have to do it forcibly by using Ctrl+C
, kill
command etc.
Internal behaviour
When reading no data for reasons such as EOF, LogReader
try to read more data every second.
For every consecutive 5 results that no data read, LogReader
checks whether or not the inode number associated with the file name was changed.
If it had been changed, LogReader
close current file and re-open the file.
Contributors
- arcage ʕ·ᴥ·ʔAKJ - creator, maintainer