Ruby 的 File.open 将模式和选项作为参数。在哪里可以找到模式和选项的完整列表？
ruby-doc.org/core-2.0.0/IO.html#method-c-new-label-IO+Open+Mode - 此页面的链接在下面的 Daniels 答案中，但您必须滚动页面才能找到它。这是文档相关部分的直接链接。
C
Casimir et Hippolyte
我想在 Ruby IO module documentation 中。
Mode | Meaning
-----+--------------------------------------------------------
"r" | Read-only, starts at beginning of file (default mode).
-----+--------------------------------------------------------
"r+" | Read-write, starts at beginning of file.
-----+--------------------------------------------------------
"w" | Write-only, truncates existing file
| to zero length or creates a new file for writing.
-----+--------------------------------------------------------
"w+" | Read-write, truncates existing file to zero length
| or creates a new file for reading and writing.
-----+--------------------------------------------------------
"a" | Write-only, starts at end of file if file exists,
| otherwise creates a new file for writing.
-----+--------------------------------------------------------
"a+" | Read-write, starts at end of file if file exists,
| otherwise creates a new file for reading and
| writing.
-----+--------------------------------------------------------
"b" | Binary file mode (may appear with
| any of the key letters listed above).
| Suppresses EOL <-> CRLF conversion on Windows. And
| sets external encoding to ASCII-8BIT unless explicitly
| specified.
-----+--------------------------------------------------------
"t" | Text file mode (may appear with
| any of the key letters listed above except "b").
S
Shadwell
File.open(filename, mode="r" [, opt])。