如何在Julia中完成相当于2>&1的操作

Question

假设我有一个命令

`echo hello`

现在,我想将STDOUT和STDERR重定向到单个流,这样就像2>&1在bash中一样.我看到两个Julia问题,但仍然不明白它应该如何在Julia v.0.4中运行.

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

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

Answer 1

请参阅帮助pipeline,特别是:

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

它将重定向到同一个流(进程STDOUT).这也可能是其他的东西.

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,你应该至少升级到Julia 0.5.0.4不再受支持,0.6将很快发布.