I can currently redirect stdout to a string variable in ruby/rails by simply running the command in bash and setting the result to my string variable as follows.
我现在可以通过在bash中运行命令并将结果设置为我的字符串变量，将stdout重定向到ruby / rails中的字符串变量，如下所示。
val = %x[ #{cmd} ]
where cmd is a string that represents a bash command.
其中cmd是表示bash命令的字符串。
However, this only captures stdout, for I want to capture stderr and set it to a string in ruby -- any ideas?
但是，这只捕获stdout，因为我想捕获stderr并将其设置为ruby中的字符串 - 任何想法？
2 个解决方案
#1
10
Simply redirect it:
只需重定向它：
val = %x[ #{cmd} 2>&1 ]
If you want to capture output from stderr only, close the file descriptor for stdout after copying it to fd 2.
如果要仅从stderr捕获输出，请在将其复制到fd 2后关闭stdout的文件描述符。
val = %x[ #{cmd} 2>&1 >/dev/null ]
#2
1
You can use Open3.popen3:
您可以使用Open3.popen3：
require 'open3'
stdin, stdout, stderr, wait_thread = Open3.popen3('ping -Z')
# => [#<IO:fd 9>, #<IO:fd 10>, #<IO:fd 12>, #<Thread:0x007fd3d30a0ce0 sleep>]
stderr.gets # => "ping: illegal option -- Z\n"
stdout.gets # => nil
#1
10
Simply redirect it:
只需重定向它：
val = %x[ #{cmd} 2>&1 ]
If you want to capture output from stderr only, close the file descriptor for stdout after copying it to fd 2.
如果要仅从stderr捕获输出，请在将其复制到fd 2后关闭stdout的文件描述符。
val = %x[ #{cmd} 2>&1 >/dev/null ]
#2
1
You can use Open3.popen3:
您可以使用Open3.popen3：
require 'open3'
stdin, stdout, stderr, wait_thread = Open3.popen3('ping -Z')
# => [#<IO:fd 9>, #<IO:fd 10>, #<IO:fd 12>, #<Thread:0x007fd3d30a0ce0 sleep>]
stderr.gets # => "ping: illegal option -- Z\n"
stdout.gets # => nil