cobc is the main command-line compiler of GnuCOBOL.
It converts COBOL source code → C code → native executable (via gcc or another C compiler).

-x tells the compiler to produce a normal executable file (with its own main() function).

• Without -x → shared library (.so / .dll) → run with cobcrun
• With -x → executable named hello → run directly ./hello

-free enables modern COBOL syntax (COBOL 2002+ style):

• No fixed 72-column layout
• No mandatory sequence numbers (cols 1–6)
• No strict Area A / Area B indentation
• Code & comments can start anywhere on the line

&& = shell "AND THEN" operator
→ next command (./hello) runs only if compilation returned success (exit code 0)

./hello
Executes the newly created binary. The compiler automatically names it after the source file (hello.cbl → hello).