Hi Ranjith, Is your operating system POSIX.1-2001 compliant, or Single Unix Specification version 2 (from 1997) compliant? Those are the standards which specify setcontext, getcontext, makecontext, and swapcontext. (If I'm not mistaken. Knock on wood.) If your operating system does not conform to POSIX.1-2001 or SUSv2 (or later), then your operating system's Standard C Library need not provide them. If provided, they would be declared in the <ucontext.h> header. HTH, --Eljay
