A programmer cannot completely understand how to use UIOP:RUN-PROGRAM without understanding the generic function SLURP-INPUT-STREAM. The documentation of the former (see docstring) refers to the latter, but the latter has no documentation:
"OUTPUT should be a value that is a suitable first argument to
SLURP-INPUT-STREAM. In this case, RUN-PROGRAM will create a temporary stream
for the program output. The program output, in that stream, will be processed
by SLURP-INPUT-STREAM, using OUTPUT as the first argument.
RUN-PROGRAM will return whatever SLURP-INPUT-STREAM returns. E.g., using
:OUTPUT :STRING will have it return the entire output stream as a string. Use
ELEMENT-TYPE and EXTERNAL-FORMAT for the stream passed to the OUTPUT processor."
If someone can supply me a docstring for SLURP-INPUT-STREAM, or even a simple sentence or two about the protocol, I (rpg) will fix it up and push it into ASDF.
It would also be helpful to explain what happens if OUTPUT is non-NIL, but a non-zero exit status results from the program invocation.
Thanks!
Whoops -- that remark about the error status is off-base -- it's all documented there.