linux - perl shebang : `Too late for "-Mstrict"`

Question

我有以下可敬的 perl 脚本 x.pl:

#!/usr/bin/env -S perl -Mstrict -wp
s/a/b/;

如果我用 ./x.pl 或 perl x.pl 运行它，它会用

Too late for "-Mstrict" option at ./x.pl line 1.

但是……为什么？我认为“为时已晚......”只是 -CSDA 或 -T 之类的问题，因为“流已经打开”。此外，shebang 行实际上不是简单地使用指定的开关调用 perl 吗？

Answer 1

-M 和 -m 开关不适用于 Perl 脚本。

#!/usr/bin/perl -Mstrict
# shebang.pl
print 42;

$ perl -Mdiagnostics shebang.pl

Too late for "-Mstrict" option at - line 1 (#1)(X) The #! line (or local equivalent) in a Perl script contains the-M, -m or -C option.

In the case of -M and -m, this is an error because those optionsare not intended for use inside scripts. Use the use pragma instead.

The -C option only works if it is specified on the command line aswell (with the same sequence of letters or numbers following). Eitherspecify this option on the command line, or, if your system supportsit, make your script executable and run it directly instead of passingit to perl.

Uncaught exception from user code:Too late for "-Mstrict" option at - line 1.