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class method

IO.write

IO.write(name, string [, offset]) → integer

IO.write(name, string [, offset] [, opt]) → integer

static VALUE
rb_io_s_write(int argc, VALUE *argv, VALUE io)
{
    return io_s_write(argc, argv, io, 0);
}

Opens the file, optionally seeks to the given offset, writes string, then returns the length written. write ensures the file is closed before returning. If offset is not given in write mode, the file is truncated. Otherwise, it is not truncated.

Example

IO.write("testfile", "0123456789", 20)  #=> 10
# File could contain:  "This is line one\nThi0123456789two\nThis is line three\nAnd so on...\n"
IO.write("testfile", "0123456789")      #=> 10
# File would now read: "0123456789"

If the last argument is a hash, it specifies options for the internal open(). It accepts the following keys:

:encoding

string or encoding

Specifies the encoding of the read string. See Encoding.aliases for possible encodings.

:mode

string or integer

Specifies the mode argument for open(). It must start with “w”, “a”, or “r+”, otherwise it will cause an error. See IO.new for the list of possible modes.

:perm

integer

Specifies the perm argument for open().

:open_args

array

Specifies arguments for open() as an array. This key can not be used in combination with other keys.

See also #write .try_convert #<< .sysopen also in 4.1 · 4.0 · 3.4 · 3.3 · 3.2 · 3.1

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