Pipe inputs from more than 1 process

Question

I am trying to automate some make commands. Along with the target we have a variable that is passed to make (corresponding to set of a #ifdef's in code).

The make command looks like this:

make <target> <MYCDEF=val>

val can take multiple values (MYCDEF_VAL1, MYCDEF_VAL2...).

target can also take multiple values like: android_arm, windows_x86, linux_x64 etc.

The MYCDEF_VALn can be found from a config.h where we check for

#elif (defined MYCDEF_VALn)

So, I can get all MYCDEF values using gawk -f script1 config.h

script1:

{
    if(/defined.*MYCDEF_/)
    {
        k=index($0, "MYCDEF_");
        print substr($0, k, index($0, ")")-k) #all lines of type defined(MYC_DEF_VALn)
    }
}

To get all targets, I can read Makefile using gawk -F: -f script2 Makefile

script2:

{if(/^[A-Za-z0-9_]+:$/) print $1}

To build for all MYCDEF_ vals with one target I can pipe the output from first script (using config.h):

gawk -f script1 config.h | xargs -I {} -n 1 make -kj windows_x86 MYCDEF={}

Similarly for all targets with one MYCDEF_val, I can pipe from second script (using Makefile).

gawk -f script2 Makefile| xargs -I {} -n 1 make -kj {} MYCDEF=MYCDEF_VAL1

Now, we want to build with all values of MYCDEF_ for all targets. It can be done using for loop:

for i in $(gawk -f script2 Makefile)
do
    gawk -f script1 config.h | xargs -I {} -n 1 make -kj $i MYCDEF={}
done

Is there a oneliner for this?

Answer 1

With GNU Parallel:

parallel -j1 make -kj {1} MYCDEF={2} :::: <(gawk -f script2 Makefile) <(gawk -f script1 config.h)

-j1 forces GNU Parallel to run the jobs in serial (which is probably what you want given the command you run is make).