j expression [[']]command1[[']] ; [[']]command2[[']]
Allows conditional execution of commands. If expression evaluates to a nonzero value, the string command1 is executed, else the string command2 is executed. The optional single quotes are used to group multiple commands (separated by semicolons) into a single command string. This command can be combined with the bp command to create conditional breakpoints:
bp _foo "j (eax>0x1) 'dd app!bar;g;'u;|' "