/* * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands. * See the copyright notice in the ACK home directory, in the file "Copyright". * */ /* Author: E.G. Keizer */ char rcs_id[] = "$Header$" ; /* Test a few declaration features */ /* Such as: forward function declarations, redeclarations, pointer to function declarations. */ static int sqr() ; /* forward declarations */ extern int sqrt(); main() { fdcl() ; hidden() ; return 0 ; } fdcl() { int (*a[2])() ; printf("sqr(4) %d\n",sqr(4)) ; a[0]=sqr ; a[1]=sqrt ; printf("(*a[0])(16) %d\n",(*a[0])(16) ) ; printf("(*a[1])( (*a[0])(3) ) %d\n", (*a[1])( (*a[0])(3) ) ) ; } static int sqr(par) int par ; { return par*par ; } int sqrt(par) int par ; { int x1,x2 ; int i ; if ( par<0 ) return -1 ; x1 = par ; i=0 ; do { x2 = x1 ; x1 = ( x2*x2 + par ) / (2*x2) ; if ( i++>=100 ) return -2 ; } while ( ( x2 0 ) ; return (x1+x2)/2 ; } int a = -8 ; hidden() { hide() ; printf("a outside hide %d\n",a) ; } int hide() { int a ; a = 4 ; printf("a in hide %d\n",a) ; { int a ; a = 16 ; printf("a in in hide %d\n",a) ; } printf("a in hide %d\n",a) ; }