bl (Breakpoint List)

Article
10/25/2023

The bl command lists information about existing breakpoints.

bl [/L] [Breakpoints]

Parameters

/L
Forces bl to always display breakpoint addresses instead of showing source file and line numbers.

Breakpoints
Specifies the ID numbers of the breakpoints to list. If you omit Breakpoints, the debugger lists all breakpoints. You can specify any number of breakpoints. You must separate multiple IDs by spaces or commas. You can specify a range of breakpoint IDs by using a hyphen (-). You can use an asterisk (*) to indicate all breakpoints. If you want to use a numeric expression for an ID, enclose it in brackets ([]). If you want to use a string with wildcard characters to match a breakpoint's symbolic name, enclose it in quotation marks ("").

Environment

Item	Description
Modes	user mode, kernel mode
Targets	live debugging only
Platforms	all

Additional Information

For more information about and examples of how to use breakpoints, other breakpoint commands and methods of controlling breakpoints, and how to set breakpoints in user space from a kernel debugger, see Using Breakpoints. For more information about conditional breakpoints, see Setting a Conditional Breakpoint.

Remarks

For each breakpoint, the command displays the following information:

The breakpoint ID. This ID is a decimal number that you can use to refer to the breakpoint in later commands.
The breakpoint status. The status can be e (enabled) or d (disabled).
(Unresolved breakpoints only) The letter "u" appears if the breakpoint is unresolved. That is, the breakpoint does not match a symbolic reference in any currently loaded module. For information about these breakpoints, see Unresolved Breakpoints (bu Breakpoints).
The virtual address or symbolic expression that makes up the breakpoint location. If you enabled source line number loading, the bl command displays file and line number information instead of address offsets. If the breakpoint is unresolved, the address is omitted here and appears at the end of the listing instead.
(Data breakpoints only) Type and size information are displayed for data breakpoints. The types can be e (execute), r (read/write), w (write), or i (input/output). These types are followed with the size of the block, in bytes. For information about these breakpoints, see Processor Breakpoints (ba Breakpoints).
The number of passes that remain until the breakpoint is activated, followed by the initial number of passes in parentheses. For more information about this kind of breakpoint, see the description of the Passes parameter in bp, bu, bm (Set Breakpoint).
The associated process and thread. If thread is given as three asterisks (***), this breakpoint is not a thread-specific breakpoint.
The module and function, with offset, that correspond to the breakpoint address. If the breakpoint is unresolved, the breakpoint address appears here instead, in parentheses. If the breakpoint is set on a valid address but symbol information is missing, this field is blank.
The command that is automatically executed when this breakpoint is hit. This command is displayed in quotation marks.

If you are not sure what command was used to set an existing breakpoint, use .bpcmds (Display Breakpoint Commands) to list all breakpoints along with the commands that were used to create them.

The following example shows the output of a bl command.

Example

0:000> bl
 0 e 010049e0     0001 (0001)  0:**** stst!main

This output contains the following information:

The breakpoint ID is 0.
The breakpoint status is e (enabled).
The breakpoint is not unresolved (there is no u in the output).
The virtual address of the breakpoint is 010049e0.
The breakpoint is active on the first pass through the code and the code has not yet been executed under the debugger. This information is indicated by a value of 1 (0001) in the "passes remaining" counter and a value of 1 ((0001)) in the initial passes counter.
This breakpoint is not a thread-specific breakpoint (***).
The breakpoint is set on main in the stst module.