WinDbg series --- symbol commonly used commands related commands

ld (Load Symbols)

ld command to load the specified module symbol of all modules and update information.

ld ModuleName [/f FileName]

parameter:

• ModuleName
  specify the name of the module to load its symbols. modulename may contain various wildcards and specifiers.
  
• / f FileName
  change the name chosen for the match. By default, the module name is matched, but when using the / f, the file name is matched, instead of module name. The file name can contain a variety of wildcard characters and specifiers.
  

The default behavior is to use the debugger delay symbol loading (also known as deferred symbol loading). This means that the symbol does not actually loaded until needed. On the other hand, ld specified load module command to force all of the symbols.

ln (List Nearest Symbols)

ln order given or displayed near the symbol address.

ln Address
ln /D Address 

parameter:

• Address
  specified address debugger to start the search symbol. We will show the most recent symbol (before or after the address).
  
• / D
  Specifies debugger markup language (DML) display output. DML output contains a link you can use this link to view recent module contains symbols. It also includes a link that can be used to set breakpoints.
  

You can use ln order to help determine what the pointer points. When you view the damage to the stack to determine which procedure has been invoked, this command is also useful. If the source line information is available, LN display also includes the source file name and line number information. If you are using the source server, then the ln command will display information related to the source server.

.copysym (Copy Symbol Files)

.copysym command to copy the current symbol file to the specified directory.

.copysym [/l] Path

parameter:

• / l
  each symbol file is loaded at the time of copying.
• Path
  specified symbol file should be copied to a directory. Copy will not overwrite existing files.
  

In many cases, the symbol stored on the network. Symbol Access is usually very slow, or you may need to transfer debug session to another computer no longer has access to the network. In this case, .copysym command can be used if desired symbol will be copied to a local directory.

.symfix (Set Symbol Store Path)

.symfix automatically command symbol path to point Microsoft symbol store.

.symfix[+] [LocalSymbolCache]

parameter:

• +
  

  Microsoft symbol store path so appended to the existing symbol path. If this is not included, then replace the existing symbol path.

• LocalSymbolCache
  designated to be used as a local symbol cache directory. If this directory does not exist, it is created when the symbol server starts copying files. If localsymbolcache omitted, the debugger installation directory sym subdirectory will be used.
  

The following example demonstrates how to use .symfix set point to Microsoft symbol store sign new path.

3: kd> .symfix c:\myCache
3: kd> .sympath
Symbol search path is: srv*
Expanded Symbol search path is: cache*c:\myCache;SRV*http://msdl.microsoft.com/download/symbols

The following example demonstrates how to use the additional .symfix + symbol path to point to an existing Microsoft symbol store path.

3: kd> .sympath
Symbol search path is: c:\someSymbols
Expanded Symbol search path is: c:\somesymbols
3: kd> .symfix+ c:\myCache
3: kd> .sympath
Symbol search path is: c:\someSymbols;srv*
Expanded Symbol search path is: c:\somesymbols;cache*c:\myCache;SRV*http://msdl.microsoft.com/download/symbols

.symopt (Set Symbol Options)

.symopt command sets or displays symbol options.

.symopt+ Flags 
.symopt- Flags 
.symopt 

parameter:

• +
  The flag symbol specified options are set. If used with .symopt and logo, but no plus or minus sign, plus sign is assumed.
• -
  the option specified by the glyph is cleared.
• Flags
  specify the options you want to change the sign. Flags must be the sum of these bits Flags symbol options.

Without any parameters, .symopt option to display the current symbol.

.sympath (Set Symbol Path)

.sympath command set or change the symbol path. Specifies the debugger symbol path where to find the symbol file.

.sympath[+] [Path [; ...]]

parameter:

• +
  Specify a new location will be appended to (rather than replacing) a symbol search path.
• Path
  list full path or full path. Multiple paths separated by semicolons. If you omit the path, the path of the current symbol is displayed.

When the symbol path changes, it will not load the new symbol information. You can use .reload (Reload Module) command to reload symbol.

! sym

This extended command and control noise symbol symbol loading tips.

!sym 
!sym noisy 
!sym quiet 
!sym prompts 
!sym prompts off

parameter:

• noisy
  activation interference symbol loading.
• quiet
  disabled interference symbol loading.
• prompts
  allow authentication dialog box is displayed when you receive authentication requests in Symsrv.
• prompts off
  when Symsrv receives a certificate request, delete all the authentication dialog box. This may lead to SYMSRV unable to access the symbols on the Internet.

If the! Sym sign extension with no arguments, shows the current status of noise and symbol loading symbol prompts. The! Sym noisy and! Sym quiet sign extension control noise mute symbol loading. The! Sym prompts and! Sym prompts off controls whether to display an authentication dialog box when symsrv experience authentication requests. These commands must be followed by .reload (re-loadable module) to take effect. Authentication requests may, Internet firewall, smart card readers and secure website sent by the proxy server.

!symsrv

Close symbol server client.

!symsrv close

This one! symsrv close extension will close any active symbol server client. If you need to resynchronize the connection, which will be very useful. If you have previously refused to authenticate Internet requests, you need to use! symsrv close to reconnect to the symbol memory.