End of Life Ruby 3.1 has reached end of life and gets no more fixes. Switch to Ruby 4.0 →

instance method

IO#readchar

ios.readchar → string

static VALUE
rb_io_readchar(VALUE io)
{
    VALUE c = rb_io_getc(io);

    if (NIL_P(c)) {
        rb_eof_error();
    }
    return c;
}

Reads a one-character string from ios. Raises an EOFError on end of file.

Example

f = File.new("testfile")
f.readchar   #=> "h"
f.readchar   #=> "e"

See also #readbyte #readline #read #readlines also in 4.1 · 4.0 · 3.4 · 3.3 · 3.2 · 3.0