The chmod utility does not set ownerships; it sets modes. Both of the above commands set the execute bits on for the file's owner, group, and for the world.

Furthermore, if the compilation was successful, the compiler will make a.out (or whatever output file was designated) executable. So, the chmod is unnecessary. (If the compilation was not successful, changing the mode won't make it execute successfully until you fix the source and rebuild it successfully.)

And, if there are other compilations that could be happening in parallel in the same directory (and to avoid an extra step, even if there aren't), it would be easier to replace:

Code:

echo "Compile this new C script as the default a.out..."
gcc cscript.c
mv a.out cscript
echo "Rename and ensure it is executable..."
chmod 755 cscript

with:

Code:

echo "Compile this new C script..."
gcc cscript.c -o cscript

or:

Code:

echo "Compile this new C script..."
make cscript