Module | Open3 |
In: |
lib/open3.rb
|
Open3 grants you access to stdin, stdout, and stderr when running another program. Example:
require "open3" include Open3 stdin, stdout, stderr = popen3('nroff -man')
Open3.popen3 can also take a block which will receive stdin, stdout and stderr as parameters. This ensures stdin, stdout and stderr are closed once the block exits. Example:
require "open3" Open3.popen3('nroff -man') { |stdin, stdout, stderr| ... }
Open stdin, stdout, and stderr streams and start external executable. Non-block form:
require 'open3' [stdin, stdout, stderr] = Open3.popen3(cmd)
Block form:
require 'open3' Open3.popen3(cmd) { |stdin, stdout, stderr| ... }
The parameter cmd is passed directly to Kernel#exec.
# File lib/open3.rb, line 46 46: def popen3(*cmd) 47: pw = IO::pipe # pipe[0] for read, pipe[1] for write 48: pr = IO::pipe 49: pe = IO::pipe 50: 51: pid = fork{ 52: # child 53: fork{ 54: # grandchild 55: pw[1].close 56: STDIN.reopen(pw[0]) 57: pw[0].close 58: 59: pr[0].close 60: STDOUT.reopen(pr[1]) 61: pr[1].close 62: 63: pe[0].close 64: STDERR.reopen(pe[1]) 65: pe[1].close 66: 67: exec(*cmd) 68: } 69: exit!(0) 70: } 71: 72: pw[0].close 73: pr[1].close 74: pe[1].close 75: Process.waitpid(pid) 76: pi = [pw[1], pr[0], pe[0]] 77: pw[1].sync = true 78: if defined? yield 79: begin 80: return yield(*pi) 81: ensure 82: pi.each{|p| p.close unless p.closed?} 83: end 84: end 85: pi 86: end