step
Continues running the program by executing the next line of source code, and then stops.
Syntax
s[tep] [count]
- count defines the number of lines to execute before stopping.
 
Usage
The step command allows you to "step" through your program
executing one line of source code at a time. When a function call appears within the line of code,
that function is also stepped through.
A common technique is to set a breakpoint prior to the section or function that is causing problems, run the program until it reaches the breakpoint, and then step through it line by line.
Example
(fgldb) step
4 call addlist(a)
(fgldb)Important: The 
step command
cannot be used to step through a function that was compiled without
debugging information. Execution continues until it reaches a function
that does have debugging information.