readlines

/*
 *  call-seq:
 *     IO.readlines(name, sep_string=$/)   => array
 *  
 *  Reads the entire file specified by <i>name</i> as individual
 *  lines, and returns those lines in an array. Lines are separated by
 *  <i>sep_string</i>.
 *     
 *     a = IO.readlines("testfile")
 *     a[0]   #=> "This is line one\n"
 *     
 */

static VALUE
rb_io_s_readlines(argc, argv, io)
    int argc;
    VALUE *argv;
    VALUE io;
{
    VALUE fname;
    struct foreach_arg arg;

    rb_scan_args(argc, argv, "11", &fname, &arg.sep);
    SafeStringValue(fname);

    arg.argc = argc - 1;
    arg.io = rb_io_open(StringValueCStr(fname), "r");
    if (NIL_P(arg.io)) return Qnil;
    return rb_ensure(io_s_readlines, (VALUE)&arg, rb_io_close, arg.io);
}