1 /* Copyright (C) 2001 Free Software Foundation, Inc.
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2, or (at your option)
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this software; see the file COPYING. If not, write to
15 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
16 * Boston, MA 02111-1307 USA
18 * As a special exception, the Free Software Foundation gives permission
19 * for additional uses of the text contained in its release of GUILE.
21 * The exception is that, if you link the GUILE library with other files
22 * to produce an executable, this does not by itself cause the
23 * resulting executable to be covered by the GNU General Public License.
24 * Your use of that executable is in no way restricted on account of
25 * linking the GUILE library code into it.
27 * This exception does not however invalidate any other reasons why
28 * the executable file might be covered by the GNU General Public License.
30 * This exception applies only to the code released by the
31 * Free Software Foundation under the name GUILE. If you copy
32 * code from other Free Software Foundation releases into a copy of
33 * GUILE, as the General Public License permits, the exception does
34 * not apply to the code that you add in this way. To avoid misleading
35 * anyone as to the status of such modified files, you must delete
36 * this exception notice from them.
38 * If you write modifications of your own for GUILE, it is your choice
39 * whether to permit this exception to apply to your modifications.
40 * If you do not wish that, delete this exception notice. */
44 /* This is the C part of the (ice-9 rw) module. */
48 #include "libguile/_scm.h"
49 #include "libguile/fports.h"
50 #include "libguile/ports.h"
51 #include "libguile/root.h"
52 #include "libguile/rw.h"
53 #include "libguile/strings.h"
54 #include "libguile/validate.h"
55 #include "libguile/modules.h"
56 #include "libguile/strports.h"
65 #define SCM_MAYBE_EAGAIN || errno == EAGAIN
67 #define SCM_MAYBE_EAGAIN
70 #if defined (EWOULDBLOCK)
71 #define SCM_MAYBE_EWOULDBLOCK || errno == EWOULDBLOCK
73 #define SCM_MAYBE_EWOULDBLOCK
76 /* MAYBE there is EAGAIN way of defining this macro but now I EWOULDBLOCK. */
77 #define SCM_EBLOCK(errno) \
78 (0 SCM_MAYBE_EAGAIN SCM_MAYBE_EWOULDBLOCK)
80 SCM_DEFINE (scm_read_string_x_partial
, "read-string!/partial", 1, 3, 0,
81 (SCM str
, SCM port_or_fdes
, SCM start
, SCM end
),
82 "Read characters from an fport or file descriptor into a\n"
83 "string @var{str}. This procedure is scsh-compatible\n"
84 "and can efficiently read large strings. It will:\n\n"
87 "attempt to fill the entire string, unless the @var{start}\n"
88 "and/or @var{end} arguments are supplied. i.e., @var{start}\n"
89 "defaults to 0 and @var{end} defaults to\n"
90 "@code{(string-length str)}\n"
92 "use the current input port if @var{port_or_fdes} is not\n"
95 "read any characters that are currently available,\n"
96 "without waiting for the rest (short reads are possible).\n\n"
98 "wait for as long as it needs to for the first character to\n"
99 "become available, unless the port is in non-blocking mode\n"
101 "return @code{#f} if end-of-file is encountered before reading\n"
102 "any characters, otherwise return the number of characters\n"
105 "return 0 if the port is in non-blocking mode and no characters\n"
106 "are immediately available.\n"
108 "return 0 if the request is for 0 bytes, with no\n"
109 "end-of-file check\n"
111 #define FUNC_NAME s_scm_read_string_x_partial
122 SCM_VALIDATE_SUBSTRING_SPEC_COPY (1, str
, dest
, 3, start
, offset
,
125 read_len
= last
- offset
;
128 if (SCM_INUMP (port_or_fdes
))
129 fdes
= SCM_INUM (port_or_fdes
);
132 SCM port
= SCM_UNBNDP (port_or_fdes
) ? scm_cur_inp
: port_or_fdes
;
134 SCM_VALIDATE_OPFPORT (2, port
);
135 SCM_VALIDATE_INPUT_PORT (2, port
);
137 /* if there's anything in the port buffers, use it, but then
138 don't touch the file descriptor. otherwise the
139 "return immediately if something is available" rule may
141 chars_read
= scm_take_from_input_buffers (port
, dest
, read_len
);
142 fdes
= SCM_FPORT_FDES (port
);
145 if (chars_read
== 0 && read_len
> 0) /* don't confuse read_len == 0 with
148 SCM_SYSCALL (chars_read
= read (fdes
, dest
, read_len
));
149 if (chars_read
== -1)
151 if (SCM_EBLOCK (errno
))
156 else if (chars_read
== 0)
159 return scm_long2num (chars_read
);
164 scm_init_rw_builtins ()
166 #ifndef SCM_MAGIC_SNARFER
167 #include "libguile/rw.x"
170 return SCM_UNSPECIFIED
;
176 scm_c_define_gsubr ("%init-rw-builtins", 0, 0, 0, scm_init_rw_builtins
);