如何与乘法增量并行运行

I know that I can use "parallel" to run multiple instances of whatever script/application in parallel over a variable with a given increment, eg:

我知道我可以使用“parallel”在具有给定增量的变量上并行运行任何脚本/应用程序的多个实例，例如：

parallel "echo hello {}" ::: {1..16..2}

Output would be:

输出将是：

hello 1
hello 3
hello 5
hello 7
hello 9
hello 11
hello 13
hello 15

I want to use an increment that multiplies the run variable so that I get an output like this:

我想使用一个与run变量相乘的增量，以便得到如下输出：

hello 1
hello 2
hello 4
hello 8
hello 16

What should I write in the {1..16..#}?

我应该在{1..16 ..＃}写什么？

Thanks!

谢谢！

2 个解决方案

#1

Try this:

尝试这个：

parallel "echo hello {}" ::: $(awk 'BEGIN {for(i=0; i<=16; i++) printf 2**i" "}')

awk is used to print out a list of powers of 2 which will then be used by parallel.

awk用于打印出2的幂列表，然后并行使用。

Alternatively:

或者：

parallel "echo hello {}" ::: $(printf '%s\n' 2^{0..16} | bc | tr '\n' ' ')

This prints out the numbers 1 to 16 as part of the string x^2, printf ensures each number is on a separate line. bc then computes the actual numbers, and tr removes the newlines again.

这打印出数字1到16作为字符串x ^ 2的一部分，printf确保每个数字在一个单独的行上。 bc然后计算实际数字，tr再次删除换行符。

#2

Use {= =} (available in version 20140822 and later):

使用{= =}（在20140822及更高版本中可用）：

seq 1 2 16 | parallel echo hello {}
parallel echo hello '{= $_=2*$_ =}' ::: {1..16}
seq 1 16 | parallel echo hello '{= $_=2**$_ =}'
parallel echo hello '{= $_=2**$_ =}'  ::: {1..16}

#1