builing a long variable-length command-pipeline

[Skaperen]

there are many tools that allow executing system commands and some can provide input and/or capture output.  but suppose you have a series of commands with the number of commands known only when the commands become known that need to be run as a pipeline (output of a command goes to input of the next).  and you may need to provide input to the first and/or capture output from the last.  how do you do this?