a

a [line] command

• Sets an action to be done before the line is executed. The following steps are taken:
  • Checks for a breakpoint at this line.
  • Prints the line if necessary.
  • Performs any actions associated with the line.
  • Prompts the user if at a breakpoint or in single-step mode.
  • Evaluates the line.

  For example, the following prints the value of $foo (and "DB FOUND") every time line 53 is passed:

  a 53 print "DB FOUND $foo\n"