instance method

ARGF#readchar

ARGF.readchar → String or nil

static VALUE
argf_readchar(VALUE argf)
{
    VALUE ch;

  retry:
    if (!next_argv()) rb_eof_error();
    if (!RB_TYPE_P(ARGF.current_file, T_FILE)) {
        ch = forward_current(rb_intern("getc"), 0, 0);
    }
    else {
        ch = rb_io_getc(ARGF.current_file);
    }
    if (NIL_P(ch) && ARGF.next_p != -1) {
        argf_close(argf);
        ARGF.next_p = 1;
        goto retry;
    }

    return ch;
}

Reads the next character from ARGF and returns it as a String. Raises an EOFError after the last character of the last file has been read.

For example:

$ echo "foo" > file
$ ruby argf.rb file

ARGF.readchar  #=> "f"
ARGF.readchar  #=> "o"
ARGF.readchar  #=> "o"
ARGF.readchar  #=> "\n"
ARGF.readchar  #=> end of file reached (EOFError)

See also #readbyte #readline #read #readlines also in 4.1 · 3.4 · 3.3 · 3.2 · 3.1 · 3.0

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