[student666]

I use this way as, after merging, all files inside polyMesh (whole mesh) are set properly, I mean, e.g in boundary file:

    { 
    version     2.0; 
    format      ascii; 
    class       polyBoundaryMesh; 
    location    "constant/polyMesh"; 
    object      boundary; 
} 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 
 
 
5  <-- THIS NUMBER
( 
airAmbInlet 
{ 
    type empty; 
    nFaces 4847;  <-- THIS  NUMBER
    startFace 4663843;  <-- THIS NUMBER
}

and others.

I think I could go through hard bash scripting, but I chose this way.