類別 Thread::Backtrace

追蹤的內部表示形式。使用者永遠不會直接與此類別的物件互動，但類別方法可用於取得目前階段的追蹤設定。

公開類別方法

Thread::Backtrace::limit → integer 按一下以切換來源

傳回由 --backtrace-limit 命令列選項設定的最大追蹤長度。預設值為 -1，表示追蹤長度無限制。如果值為零或正數，Exception#full_message 產生的錯誤追蹤會縮寫，而額外行會以 ... 3 層級... 取代。

$ ruby -r net/http -e "p Thread::Backtrace.limit; Net::HTTP.get(URI('http://wrong.address'))"
- 1
.../lib/ruby/3.1.0/socket.rb:227:in `getaddrinfo': Failed to open TCP connection to wrong.address:80 (getaddrinfo: Name or service not known) (SocketError)
    from .../lib/ruby/3.1.0/socket.rb:227:in `foreach'
    from .../lib/ruby/3.1.0/socket.rb:632:in `tcp'
    from .../lib/ruby/3.1.0/net/http.rb:998:in `connect'
    from .../lib/ruby/3.1.0/net/http.rb:976:in `do_start'
    from .../lib/ruby/3.1.0/net/http.rb:965:in `start'
    from .../lib/ruby/3.1.0/net/http.rb:627:in `start'
    from .../lib/ruby/3.1.0/net/http.rb:503:in `get_response'
    from .../lib/ruby/3.1.0/net/http.rb:474:in `get'
.../lib/ruby/3.1.0/socket.rb:227:in `getaddrinfo': getaddrinfo: Name or service not known (SocketError)
    from .../lib/ruby/3.1.0/socket.rb:227:in `foreach'
    from .../lib/ruby/3.1.0/socket.rb:632:in `tcp'
    from .../lib/ruby/3.1.0/net/http.rb:998:in `connect'
    from .../lib/ruby/3.1.0/net/http.rb:976:in `do_start'
    from .../lib/ruby/3.1.0/net/http.rb:965:in `start'
    from .../lib/ruby/3.1.0/net/http.rb:627:in `start'
    from .../lib/ruby/3.1.0/net/http.rb:503:in `get_response'
    from .../lib/ruby/3.1.0/net/http.rb:474:in `get'
    from -e:1:in `<main>'

$ ruby --backtrace-limit 2 -r net/http -e "p Thread::Backtrace.limit; Net::HTTP.get(URI('http://wrong.address'))"
2
.../lib/ruby/3.1.0/socket.rb:227:in `getaddrinfo': Failed to open TCP connection to wrong.address:80 (getaddrinfo: Name or service not known) (SocketError)
    from .../lib/ruby/3.1.0/socket.rb:227:in `foreach'
    from .../lib/ruby/3.1.0/socket.rb:632:in `tcp'
     ... 7 levels...
.../lib/ruby/3.1.0/socket.rb:227:in `getaddrinfo': getaddrinfo: Name or service not known (SocketError)
    from .../lib/ruby/3.1.0/socket.rb:227:in `foreach'
    from .../lib/ruby/3.1.0/socket.rb:632:in `tcp'
     ... 7 levels...

$ ruby --backtrace-limit 0 -r net/http -e "p Thread::Backtrace.limit; Net::HTTP.get(URI('http://wrong.address'))"
0
.../lib/ruby/3.1.0/socket.rb:227:in `getaddrinfo': Failed to open TCP connection to wrong.address:80 (getaddrinfo: Name or service not known) (SocketError)
     ... 9 levels...
.../lib/ruby/3.1.0/socket.rb:227:in `getaddrinfo': getaddrinfo: Name or service not known (SocketError)
     ... 9 levels...

static VALUE
backtrace_limit(VALUE self)
{
    return LONG2NUM(rb_backtrace_length_limit);
}