-pie 单行模式下的 Perl 调试器操作?

Question

考虑一下：

cat > mytestfile.txt <<'EOF'
"'iceberg'"
"'ice cliff'"
"'ice field'"
"'inlet'"
"'island'"
"'islet'"
"'isthmus'"
EOF
perl -dpi -e 's/ice/dice/' mytestfile.txt

当调试器运行时，我尝试添加一个操作来打印$_，但是：

$ perl -dpi -e 's/ice/dice/' mytestfile.txt 
Loading DB routines from perl5db.pl version 1.39_10
Editor support available.
Enter h or 'h h' for help, or 'man perldebug' for more help.
main::(-e:0):   BEGIN { require 'perl5db.pl' };LINE: while (<>) {
DB<1> n
main::(-e:1):   s/ice/dice/
DB<1> n
main::(-e:0):   BEGIN { require 'perl5db.pl' };LINE: while (<>) {
DB<1> print $_
DB<2> n
main::(-e:1):   s/ice/dice/
DB<2> print $_
DB<3> n
main::(-e:0):   BEGIN { require 'perl5db.pl' };LINE: while (<>) {
DB<3> p $_
"'ddiceberg'"
DB<4> print "$_"
...
DB<1> a 0 print "$_";
DB<2> L  
DB<3> L a
DB<4> n
...
DB<6> a 1 print "$_"
DB<7> L a
-e:
1: s/ice/dice/
action:  print "$_"
DB<8> n
main::(-e:1):   s/ice/dice/
DB<8> n
main::(-e:0):   BEGIN { require 'perl5db.pl' };LINE: while (<>) {
DB<8> n
main::(-e:1):   s/ice/dice/
DB<8> n
main::(-e:0):   BEGIN { require 'perl5db.pl' };LINE: while (<>) {
DB<8> n
...
DB<8> a 1 p $_
DB<9> L a
-e:
1: s/ice/dice/
action:  p $_
DB<10> n
main::(-e:1):   s/ice/dice/
Can't locate object method "p" via package "    "'ice cliff'"
" (perhaps you forgot to load "    "'ice cliff'"
"?) at (eval 13)[/usr/share/perl/5.18/perl5db.pl:732] line 1, <> line 3.
DB<10> n
main::(-e:0):   BEGIN { require 'perl5db.pl' };LINE: while (<>) {
Can't locate object method "p" via package "    "'dice cliff'"
" (perhaps you forgot to load "    "'dice cliff'"
"?) at (eval 14)[/usr/share/perl/5.18/perl5db.pl:732] line 1, <> line 3.

。存在问题：

• 如果我做print $_，我得到一个空字符串 - 如果我做p $_，我确实得到变量的实际打印输出
• 我无法在第 0 行添加操作
• 在第 1 行，操作执行 - 但如果将print $_用作操作，它看起来不像，因为如前所述，它返回空字符串;但p $_即使它以交互模式打印，当用作操作时也会引发错误。

那么，如何将每个循环打印$_"美元下划线"之类的内容作为调试-pie脚本的操作呢？

Answer 1

通过 如何在perl调试器中的<操作中运行">

DB<1> { p $_
DB<2> n
main::(-e:1):   s/ice/dice/
auto(-1)  DB<2> p $_
"'iceberg'"
DB<3> n
main::(-e:0):   BEGIN { require 'perl5db.pl' };LINE: while (<>) {
auto(-1)  DB<3> p $_
"'diceberg'"
DB<4> n
main::(-e:1):   s/ice/dice/
auto(-1)  DB<4> p $_
"'ice cliff'"
DB<5> n
main::(-e:0):   BEGIN { require 'perl5db.pl' };LINE: while (<>) {
auto(-1)  DB<5> p $_
"'dice cliff'"