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. */
53 #include "libguile/_scm.h"
54 #include "libguile/fports.h"
55 #include "libguile/ports.h"
56 #include "libguile/root.h"
57 #include "libguile/rw.h"
58 #include "libguile/strings.h"
59 #include "libguile/validate.h"
60 #include "libguile/modules.h"
61 #include "libguile/strports.h"
73 #define SCM_MAYBE_EAGAIN || errno == EAGAIN
75 #define SCM_MAYBE_EAGAIN
78 #if defined (EWOULDBLOCK)
79 #define SCM_MAYBE_EWOULDBLOCK || errno == EWOULDBLOCK
81 #define SCM_MAYBE_EWOULDBLOCK
84 /* MAYBE there is EAGAIN way of defining this macro but now I EWOULDBLOCK. */
85 #define SCM_EBLOCK(errno) \
86 (0 SCM_MAYBE_EAGAIN SCM_MAYBE_EWOULDBLOCK)
88 SCM_DEFINE (scm_read_string_x_partial
, "read-string!/partial", 1, 3, 0,
89 (SCM str
, SCM port_or_fdes
, SCM start
, SCM end
),
90 "Read characters from a port or file descriptor into a\n"
91 "string @var{str}. A port must have an underlying file\n"
92 "descriptor --- a so-called fport. This procedure is\n"
93 "scsh-compatible and can efficiently read large strings.\n"
97 "attempt to fill the entire string, unless the @var{start}\n"
98 "and/or @var{end} arguments are supplied. i.e., @var{start}\n"
99 "defaults to 0 and @var{end} defaults to\n"
100 "@code{(string-length str)}\n"
102 "use the current input port if @var{port_or_fdes} is not\n"
105 "return fewer than the requested number of characters in some\n"
106 "cases, e.g., on end of file, if interrupted by a signal, or if\n"
107 "not all the characters are immediately available.\n"
109 "wait indefinitely for some input if no characters are\n"
110 "currently available,\n"
111 "unless the port is in non-blocking mode.\n"
113 "read characters from the port's input buffers if available,\n"
114 "instead from the underlying file descriptor.\n"
116 "return @code{#f} if end-of-file is encountered before reading\n"
117 "any characters, otherwise return the number of characters\n"
120 "return 0 if the port is in non-blocking mode and no characters\n"
121 "are immediately available.\n"
123 "return 0 if the request is for 0 bytes, with no\n"
124 "end-of-file check.\n"
126 #define FUNC_NAME s_scm_read_string_x_partial
137 SCM_VALIDATE_SUBSTRING_SPEC_COPY (1, str
, dest
, 3, start
, offset
,
140 read_len
= last
- offset
;
143 if (SCM_INUMP (port_or_fdes
))
144 fdes
= SCM_INUM (port_or_fdes
);
147 SCM port
= SCM_UNBNDP (port_or_fdes
) ? scm_cur_inp
: port_or_fdes
;
149 SCM_VALIDATE_OPFPORT (2, port
);
150 SCM_VALIDATE_INPUT_PORT (2, port
);
152 /* if there's anything in the port buffers, use it, but then
153 don't touch the file descriptor. otherwise the
154 "return immediately if something is available" rule may
156 chars_read
= scm_take_from_input_buffers (port
, dest
, read_len
);
157 fdes
= SCM_FPORT_FDES (port
);
160 if (chars_read
== 0 && read_len
> 0) /* don't confuse read_len == 0 with
163 SCM_SYSCALL (chars_read
= read (fdes
, dest
, read_len
));
164 if (chars_read
== -1)
166 if (SCM_EBLOCK (errno
))
171 else if (chars_read
== 0)
174 return scm_long2num (chars_read
);
178 SCM_DEFINE (scm_write_string_partial
, "write-string/partial", 1, 3, 0,
179 (SCM str
, SCM port_or_fdes
, SCM start
, SCM end
),
180 "Write characters from a string @var{str} to a port or file\n"
181 "descriptor. A port must have an underlying file descriptor\n"
182 "--- a so-called fport. This procedure is\n"
183 "scsh-compatible and can efficiently write large strings.\n"
187 "attempt to write the entire string, unless the @var{start}\n"
188 "and/or @var{end} arguments are supplied. i.e., @var{start}\n"
189 "defaults to 0 and @var{end} defaults to\n"
190 "@code{(string-length str)}\n"
192 "use the current output port if @var{port_of_fdes} is not\n"
195 "in the case of a buffered port, store the characters in the\n"
196 "port's output buffer, if all will fit. If they will not fit\n"
197 "then any existing buffered characters will be flushed\n"
198 "before attempting\n"
199 "to write the new characters directly to the underlying file\n"
200 "descriptor. If the port is in non-blocking mode and\n"
201 "buffered characters can not be flushed immediately, then an\n"
202 "@code{EAGAIN} system-error exception will be raised (Note:\n"
203 "scsh does not support the use of non-blocking buffered ports.)\n"
205 "write fewer than the requested number of\n"
206 "characters in some cases, e.g., if interrupted by a signal or\n"
207 "if not all of the output can be accepted immediately.\n"
209 "wait indefinitely for at least one character\n"
210 "from @var{str} to be accepted by the port, unless the port is\n"
211 "in non-blocking mode.\n"
213 "return the number of characters accepted by the port.\n"
215 "return 0 if the port is in non-blocking mode and can not accept\n"
216 "at least one character from @var{str} immediately\n"
218 "return 0 immediately if the request size is 0 bytes.\n"
220 #define FUNC_NAME s_scm_write_string_partial
230 SCM_VALIDATE_SUBSTRING_SPEC_COPY (1, str
, src
, 3, start
, offset
,
233 write_len
= last
- offset
;
239 if (SCM_INUMP (port_or_fdes
))
240 fdes
= SCM_INUM (port_or_fdes
);
243 SCM port
= SCM_UNBNDP (port_or_fdes
) ? scm_cur_outp
: port_or_fdes
;
247 SCM_VALIDATE_OPFPORT (2, port
);
248 SCM_VALIDATE_OUTPUT_PORT (2, port
);
249 pt
= SCM_PTAB_ENTRY (port
);
250 /* filling the last character in the buffer would require a flush. */
251 space
= pt
->write_end
- pt
->write_pos
- 1;
252 if (space
>= write_len
)
254 memcpy (pt
->write_pos
, src
, write_len
);
255 pt
->write_pos
+= write_len
;
256 return scm_long2num (write_len
);
258 if (pt
->write_pos
> pt
->write_buf
)
260 fdes
= SCM_FPORT_FDES (port
);
265 SCM_SYSCALL (rv
= write (fdes
, src
, write_len
));
268 if (SCM_EBLOCK (errno
))
274 return scm_long2num (rv
);
280 scm_init_rw_builtins ()
282 #include "libguile/rw.x"
284 return SCM_UNSPECIFIED
;
290 scm_c_define_gsubr ("%init-rw-builtins", 0, 0, 0, scm_init_rw_builtins
);