Bash: How to feed a command with the multiple results generated by one subcommand

You mean like

   for i in file*.c ; do        myprocess `gcc -E $i`    done

If this is part of an ongoing processes (as opposed to a one time thing), use make, it is good at automating work pipelines.

In particular use suffix rules with traditional make or gmake style implicit rules.

Here is an outline for a suffix rule implementation:

.c.cpre:         $(CC) -E $(CPPFLAGS) -o $@ $<.cpre.cmy:         $(MY_PROCESS) $<         # Or whatever syntax you support..         #         # You could          # $(RM) $<         # here, but I don't recommend it.cmy.o:         $(CC) -c $(CFLAGS) $(CPPFLAGS) -o $@ $<         # $(RM) $<

No magic nedded, just

my_process $(gcc -E *.c)

Note that I used the $(command) form because backticks are deprecated.

As an aside: are you sure you want to do that? You are putting the whole output of gcc -E as command line parameters of my_process. Not sure this is what you want. Maybe you want to use a simple pipe

gcc -E file.c | my_process

so that the output of gcc becomes the input of my_process.

In the latter case something like

for c_file in *.c ; do    gcc -E $c_file | myprocess > ${c_file}.processeddone

would do the trick.