A breakpoint causes the program to stop whenever a certain point in the program is reached. It can be set in several ways using the break command. Breakpoints are assigned numbers when set, for further reference. The most comfortable way to set breakpoints is through the Emacs interface (see section 16.10).
Set a breakpoint at the current position in the program execution. The current position must be on an event (i.e., neither at the beginning, nor at the end of the program).
Set a breakpoint at the beginning of function. This works only when the functional value of the identifier function has been computed and assigned to the identifier. Hence this command cannot be used at the very beginning of the program execution, when all identifiers are still undefined; use goto time to advance execution until the functional value is available.
Set a breakpoint in module module (or in the current module if module is not given), at the first event of line line.
Set a breakpoint in module module (or in the current module if module is not given), at the event closest to line line, column column.
Set a breakpoint in module module at the event closest to character number character. : break address | Set a breakpoint at the code address address.
Delete the specified breakpoints. Without argument, all breakpoints are deleted (after asking for confirmation).
Print the list of all breakpoints.