User`s guide

Chapter 5: Examining and Changing Data

(dbx) print i

(dbx) up

foo: 40 r = foo2(i+1);

The current activation level is now the procedure foo. As indicated in the

output, the variable i receives the argument passed to foo and is therefore

local to foo. The variable i at this activation level is different from the

variable i in the foo2 activation level. You can reference the currently active

i as “i”; whereas you must qualify the reference to the i in foo2:

(dbx) print i

(dbx) print foo2.i

Moving up one more activation level brings you to the main procedure:

(dbx) up

main: 25 j = foo(j);

(dbx) file

/usr/var/tmp/dbx_examples/test4.c

In this example, the source for main is in test4.c, whereas the source for foo

and foo2 is in foo.c; therefore, dbx changes the current source ﬁle when you

move up to the main activation level.

dbx resets the source ﬁle when you return to the foo2 activation level:

(dbx) down 2

foo2: 46 printf(“foo2 arg is %d\n”,i);

(dbx) file

/usr/var/tmp/dbx_examples/foo.c

Moving to a Speciﬁed Procedure

The func command moves you up or down the activation stack. You can

specify the new activation level by providing either a procedure name or an

activation level number.