Method: IO.foreach

Defined in:

io.c

.foreach(name, sep = $/[, open_args]) {|line| ... } ⇒ nil .foreach(name, limit[, open_args]) {|line| ... } ⇒ nil .foreach(name, sep, limit[, open_args]) {|line| ... } ⇒ nil .foreach(...) ⇒ Object

Executes the block for every line in the named I/O port, where lines are separated by sep.

If no block is given, an enumerator is returned instead.

IO.foreach("testfile") {|x| print "GOT ", x }

produces:

GOT This is line one
GOT This is line two
GOT This is line three
GOT And so on...

If the last argument is a hash, it’s the keyword argument to open. See IO.read for detail.

Overloads:

• .foreach(name, sep = $/[, open_args]) {|line| ... } ⇒ nil

  Yields:

  • (line)

  Returns:

  • (nil)
• .foreach(name, limit[, open_args]) {|line| ... } ⇒ nil

  Yields:

  • (line)

  Returns:

  • (nil)
• .foreach(name, sep, limit[, open_args]) {|line| ... } ⇒ nil

  Yields:

  • (line)

  Returns:

  • (nil)

# File 'io.c', line 9746

static VALUE
rb_io_s_foreach(int argc, VALUE *argv, VALUE self)
{
    VALUE opt;
    int orig_argc = argc;
    struct foreach_arg arg;

    argc = rb_scan_args(argc, argv, "13:", NULL, NULL, NULL, NULL, &opt);
    RETURN_ENUMERATOR(self, orig_argc, argv);
    open_key_args(argc, argv, opt, &arg);
    if (NIL_P(arg.io)) return Qnil;
    return rb_ensure(io_s_foreach, (VALUE)&arg, rb_io_close, arg.io);
}