名前¶

Fatal - 関数を、成功しなければ die する等価物に置き換える

概要¶

    use Fatal qw(open close);

    open(my $fh, "<", $filename);  # No need to check errors!

    use File::Copy qw(move);
    use Fatal qw(move);

    move($file1, $file2); # No need to check errors!

    sub juggle { . . . }
    Fatal->import('juggle');

BEST PRACTICE¶

Fatal は新しい autodie プラグマによって古いものになりました。 Fatal よりも autodie を使ってください。 autodie はレキシカルスコープに対応し、実例外オブジェクトを投げ、 遥かによいエラーメッセージを提供します。

Fatal での :void の仕様は非推奨です。

説明¶

Fatal provides a way to conveniently replace functions which normally return a false value when they fail with equivalents which raise exceptions if they are not successful. This lets you use these functions without having to test their return values explicitly on each call. Exceptions can be caught using eval{}. See perlfunc and perlvar for details. (TBT)

The do-or-die equivalents are set up simply by calling Fatal's import routine, passing it the names of the functions to be replaced. You may wrap both user-defined functions and overridable CORE operators (except exec, system, print, or any other built-in that cannot be expressed via prototypes) in this way. (TBT)

If the symbol :void appears in the import list, then functions named later in that import list raise an exception only when these are called in void context--that is, when their return values are ignored. For example (TBT)

    use Fatal qw/:void open close/;

    # properly checked, so no exception raised on error
    if (not open(my $fh, '<', '/bogotic') {
        warn "Can't open /bogotic: $!";
    }

    # not checked, so error raises an exception
    close FH;

The use of :void is discouraged, as it can result in exceptions not being thrown if you accidentally call a method without void context. Use autodie instead if you need to be able to disable autodying/Fatal behaviour for a small block of code. (TBT)

DIAGNOSTICS¶

Bad subroutine name for Fatal: %s

You've called Fatal with an argument that doesn't look like a subroutine name, nor a switch that this version of Fatal understands.

You've called Fatal with an argument that doesn't look like a subroutine name, nor a switch that this version of Fatal understands. (TBT)

%s is not a Perl subroutine

You've asked Fatal to try and replace a subroutine which does not exist, or has not yet been defined.

You've asked Fatal to try and replace a subroutine which does not exist, or has not yet been defined. (TBT)

%s is neither a builtin, nor a Perl subroutine

You've asked Fatal to replace a subroutine, but it's not a Perl built-in, and Fatal couldn't find it as a regular subroutine. It either doesn't exist or has not yet been defined.

You've asked Fatal to replace a subroutine, but it's not a Perl built-in, and Fatal couldn't find it as a regular subroutine. It either doesn't exist or has not yet been defined. (TBT)

Cannot make the non-overridable %s fatal

You've tried to use Fatal on a Perl built-in that can't be overridden, such as print or system, which means that Fatal can't help you, although some other modules might. See the "SEE ALSO" section of this documentation.

You've tried to use Fatal on a Perl built-in that can't be overridden, such as print or system, which means that Fatal can't help you, although some other modules might. See the "SEE ALSO" section of this documentation. (TBT)

Internal error: %s

You've found a bug in Fatal. Please report it using the perlbug command.

You've found a bug in Fatal. Please report it using the perlbug command. (TBT)

バグ¶

Fatal clobbers the context in which a function is called and always makes it a scalar context, except when the :void tag is used. This problem does not exist in autodie. (TBT)

"Used only once" warnings can be generated when autodie or Fatal is used with package filehandles (eg, FILE). It's strongly recommended you use scalar filehandles instead. (TBT)

作者¶

元のモジュールは Lionel Cons (CERN)。

プロトタイプの更新は Ilya Zakharevich <ilya@math.ohio-state.edu>。

autodie 対応、バグ修正、診断メッセージの拡張、system 対応、 大幅なオーバーホールは Paul Fenwick <pjf@perltraining.com.au>。

ライセンス¶

This module is free software, you may distribute it under the same terms as Perl itself.

SEE ALSO¶

レキシカルに Fatal をつかうよりよい方法である autodie。

system() と逆クォートに関する似たようなアイデアである IPC::System::Simple。