Thus spake Joel Uckelman:
>
> When I run this:
>
> seq 3 | parallel --results b -n0 echo hey
>
> parallel writes me a directory tree like this:
>
> [uckelman@scylla tmp]$ tree b
> b
> └── 1
> └── \\0
> ├── seq
> ├── stderr
> └── stdout
I think I figured out why this happens---there is only one input
source (represented by b/1) and there is only one unique value which
comes from it, i.e., nothing, due to -n0, which gets represented
as a null escape, \0.
It looks like what I want instead is this:
seq 3 | parallel --results b 'echo hey ; true'
Each run gets a unique value from the input, but those arguments are
all fed to 'true', which safely ignores the arguments it's given.
This gives me
[uckelman@scylla tmp]$ tree b
b
└── 1
├── 1
│ ├── seq
│ ├── stderr
│ └── stdout
├── 2
│ ├── seq
│ ├── stderr
│ └── stdout
└── 3
├── seq
├── stderr
└── stdout
which is what I was aiming for.
Is using true as a no-op argument eater the most obvious way of
collecting the output from multiple same-argument invocations of one
command?
--
J.
