j expr ["cmds"]
The j command executes the specified commands when the specified expression is TRUE. If expr is FALSE, the debugger continues to the next command line (excluding the commands in cmds).
The j command is useful in breakpoint commands to conditionally break execution when an expression becomes TRUE.
expr
Evaluates to a Boolean TRUE or FALSE.
cmds
Specifies a list of debugger commands to be executed when expr is TRUE. The list must be enclosed in single or double quotation marks. You must separate optional commands with semicolons (;). Single commands do not require quotation marks.
The following example causes execution to break if AX does not equal zero when the breakpoint is reached:
bp 167:1454 "J AX == 0;G"
The following example displays the registers and continues execution when the byte pointed to by DS:SI +3 is equal to 40h; otherwise, it displays the descriptor table:
bp 167:1462 "J BY (DS:SI+3) == 40 'R;G';DG DS"