如何在朱莉娅中做相当于 2>&1 的操作

Question

假设我有一个命令

`echo hello`

现在，我想将 STDOUT 和 STDERR 重定向到一个流，这样它就像 bash 中的2>&1一样。我看到了两个 Julia 问题，但仍然不明白它在 Julia v.0.4 中应该如何工作。

https://github.com/JuliaLang/julia/issues/5344

https://github.com/JuliaLang/julia/issues/5349

Answer 1

请参阅pipeline帮助，特别是：

run(pipeline(`echo hello`, stdout=STDOUT, stderr=STDOUT))

这会将两者重定向到同一流(进程STDOUT(。这也可以是其他东西。

以下是您可以从 REPL 获得的帮助：

help?> pipeline
search: pipeline
  pipeline(command; stdin, stdout, stderr, append=false)
  Redirect I/O to or from the given command. Keyword arguments specify which
  of the command's streams should be redirected. append controls whether file
  output appends to the file. This is a more general version of the 2-argument
  pipeline function. pipeline(from, to) is equivalent to pipeline(from,
  stdout=to) when from is a command, and to pipeline(to, stdin=from) when from
  is another kind of data source.
  Examples:
  run(pipeline(`dothings`, stdout="out.txt", stderr="errs.txt"))
  run(pipeline(`update`, stdout="log.txt", append=true))
  pipeline(from, to, ...)
  Create a pipeline from a data source to a destination. The source and
  destination can be commands, I/O streams, strings, or results of other
  pipeline calls. At least one argument must be a command. Strings refer to
  filenames. When called with more than two arguments, they are chained
  together from left to right. For example pipeline(a,b,c) is equivalent to
  pipeline(pipeline(a,b),c). This provides a more concise way to specify
  multi-stage pipelines.
  Examples:
  run(pipeline(`ls`, `grep xyz`))
  run(pipeline(`ls`, "out.txt"))
  run(pipeline("out.txt", `grep xyz`))

此外，您应该至少升级到 Julia 0.5。 0.4 不再受支持，0.6 将很快发布。