User`s guide

Stepping Through Your Program

Stepping Using the

step

Command

The format of the step command is:

step [integer] Executes the speciﬁed number of lines of source code,

stepping into procedures. If you do not provide an

argument, step executes one line. If step encounters any

breakpoints, it immediately stops execution.

By default, step steps into only those procedures that are compiled with the

debugging option –g. Note that this does not include standard library

routines because they are not compiled using debugging options.

You can modify this behavior, even force dbx to step into procedures not

compiled with full debugging information, by changing the value of the dbx

variable $stepintoall. Table 6-1 summarizes how the value of $stepintoall

affects dbx’s treatment of the step command.

Stepping Using the

Command

The format of the next command is:

next [integer] Executes the speciﬁed number of lines of source code,

stepping over procedures. If you do not provide an

argument, next executes one line. If next encounters any

breakpoints, even in procedures that it steps over, it

immediately stops execution.

Table 6-1 Effect of $stepintoall Variable on the step Command

$stepintoall

value

Effect on

step

Command

0 (default) step steps into only those procedures that are compiled with the

debugging option –

g. step steps over all other procedures.

1 or 2 step steps into all procedures. Note that when you debug a

source ﬁle compiled without symbols or compiled with

optimization, the line numbers may sometimes jump erratically.

Also note that if dbx cannot locate a source ﬁle, then it cannot

display source lines as you step through a procedure.