Script started on Wed Sep 26 23:01:59 2001
linux3% gdb a.out
GNU gdb 19991004
Copyright 1998 Free Software Foundation, Inc.

(gdb) disas *pstart
Dump of assembler code for function pstart:
0x8048081 <pstart>:     mov    %eax,0x80490c0
0x8048086 <pstart+5>:   call   0x80480a1 <print>
0x804808b <pstart+10>:  mov    %eax,0x80490cd
0x8048090 <pstart+15>:  call   0x80480a1 <print>
0x8048095 <pexit>:      mov    %eax,0x1
0x804809a <pexit+5>:    mov    %ebx,0x0
0x804809f <pexit+10>:   int    0x80
End of assembler dump.

(gdb) break *pstart
Breakpoint 1 at 0x8048081
(gdb) break *print
Breakpoint 2 at 0x80480a1

(gdb) run
Starting program: /afs/umbc.edu/users/c/h/chang/home/asm/sub/a.out 

Breakpoint 1, 0x8048081 in pstart ()
(gdb) print/x $esp
$1 = 0x7ffffb90
(gdb) cont
Continuing.

Breakpoint 2, 0x80480a1 in print ()
(gdb) print/x $esp
$2 = 0x7ffffb8c
(gdb) x/1wx $esp
0x7ffffb8c:     0x0804808b
(gdb) cont
Continuing.
Hello World

Breakpoint 2, 0x80480a1 in print ()
(gdb) print/x $eax
$3 = 0x80490cd
(gdb) x/20cb &msg2
0x80490cd <msg2>:       71 'G'  111 'o' 111 'o' 100 'd' 45 '-'  98 'b'  121 'y' 101 'e'
0x80490d5 <msg2+8>:     44 ','  32 ' '  98 'b'  108 'l' 117 'u' 101 'e' 32 ' '  115 's'
0x80490dd <msg2+16>:    107 'k' 121 'y' 10 '\n' 0 '\000'
(gdb) x/1wx $esp
0x7ffffb8c:     0x08048095

(gdb) cont
Continuing.
Good-bye, blue sky

Program exited normally.
(gdb) quit
linux3% exit