module Cabin::Mixins::Pipe
This module provides a ‘pipe’ method which instructs cabin to pipe anything read from the IO given to be logged.
Public Instance Methods
pipe(io_to_method_map, &block)
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Pipe
IO objects to method calls on a logger.
The argument is a hash of IO to method symbols.
logger.pipe(io => :the_method)
For each line read from ‘io’, logger.the_method(the_line) will be called.
Example:
cmd = "strace -e trace=write date" Open4::popen4(cmd) do |pid, stdin, stdout, stderr| stdin.close # Make lines from stdout be logged as 'info' # Make lines from stderr be logged as 'error' logger.pipe(stdout => :info, stderr => :error) end
Output:
write(1, "Fri Jan 11 22:49:42 PST 2013\n", 29) = 29 {"level":"error"} Fri Jan 11 22:49:42 PST 2013 {"level":"info"} +++ exited with 0 +++ {"level":"error"}
# File lib/cabin/mixins/pipe.rb, line 31 def pipe(io_to_method_map, &block) fds = io_to_method_map.keys while !fds.empty? readers, _, _ = IO.select(fds, nil, nil, nil) readers.each do |fd| begin line = fd.readline.chomp rescue EOFError fd.close rescue nil fds.delete(fd) next end method_name = io_to_method_map[fd] block.call(line, method_name) if block_given? send(method_name, line) end # readers.each end # while !fds.empty? end