% cat testdiv2.c
main() {
	int i;
	i = div2(-1);
	printf("-1/2 = %d\n", i);
}
div2(i) {
	int j;
	j = i>>1;
	return(j);
}

% cc -g testdiv2.c

% a.out
-1/2 = -1

% sdb
No core image			# Warning message from sdb
*/^div2				# Search for procedure "div2"
6: div2(i) {			# It starts at line 6
*z				# Print the next few lines
6: div2(i) {
7: 	int j;
8: 	j = i>>1;
9: 	return(j);
10: }
*div2:b				# Place a breakpoint at beginning of div2
div2:8 b			# Sdb echoes proc name and line number
*r				# Run the procedure
Breakpoint at			# Execution stops just before line 8
div2:8: 	j = i>>1;
*t				# Print trace of subroutine calls
div2(-1)   [testdiv2.c:8]
main(1,2147483380,2147483388)   [testdiv2.c:3]
*i/				# Print i
-1
*s				# Single step
div2:9: 	return(j);	# Execution stops just before line 9
*j/				# Print j
-1
*8d				# Delete the breakpoint
*div2(1)/			# Try running div2 with different args
0
*div2(-2)/
-1
*div2(-3)/
-2
*q				# Exit sdb