1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2006 Free Software Foundation, Inc.
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public License
5 * as published by the Free Software Foundation; either version 3 of
6 * the License, or (at your option) any later version.
8 * This library is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Lesser General Public License for more details.
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
23 #include "libguile/_scm.h"
31 #include "libguile/chars.h"
32 #include "libguile/modules.h"
33 #include "libguile/ports.h"
34 #include "libguile/rdelim.h"
35 #include "libguile/root.h"
36 #include "libguile/strings.h"
37 #include "libguile/strports.h"
38 #include "libguile/validate.h"
40 SCM_DEFINE (scm_read_delimited_x
, "%read-delimited!", 3, 3, 0,
41 (SCM delims
, SCM str
, SCM gobble
, SCM port
, SCM start
, SCM end
),
42 "Read characters from @var{port} into @var{str} until one of the\n"
43 "characters in the @var{delims} string is encountered. If\n"
44 "@var{gobble} is true, discard the delimiter character;\n"
45 "otherwise, leave it in the input stream for the next read. If\n"
46 "@var{port} is not specified, use the value of\n"
47 "@code{(current-input-port)}. If @var{start} or @var{end} are\n"
48 "specified, store data only into the substring of @var{str}\n"
49 "bounded by @var{start} and @var{end} (which default to the\n"
50 "beginning and end of the string, respectively).\n"
52 " Return a pair consisting of the delimiter that terminated the\n"
53 "string and the number of characters read. If reading stopped\n"
54 "at the end of file, the delimiter returned is the\n"
55 "@var{eof-object}; if the string was filled without encountering\n"
56 "a delimiter, this value is @code{#f}.")
57 #define FUNC_NAME s_scm_read_delimited_x
65 SCM_VALIDATE_STRING (1, delims
);
66 num_delims
= scm_i_string_length (delims
);
68 SCM_VALIDATE_STRING (2, str
);
69 scm_i_get_substring_spec (scm_i_string_length (str
),
70 start
, &cstart
, end
, &cend
);
72 if (SCM_UNBNDP (port
))
73 port
= scm_current_input_port ();
75 SCM_VALIDATE_OPINPORT (4, port
);
77 for (j
= cstart
; j
< cend
; j
++)
82 for (k
= 0; k
< num_delims
; k
++)
84 if (scm_i_string_ref (delims
, k
) == c
)
86 if (scm_is_false (gobble
))
89 return scm_cons (SCM_MAKE_CHAR (c
),
90 scm_from_size_t (j
- cstart
));
94 return scm_cons (SCM_EOF_VAL
,
95 scm_from_size_t (j
- cstart
));
97 scm_c_string_set_x (str
, j
, SCM_MAKE_CHAR (c
));
99 return scm_cons (SCM_BOOL_F
, scm_from_size_t (j
- cstart
));
103 static unsigned char *
104 scm_do_read_line (SCM port
, size_t *len_p
)
106 scm_t_port
*pt
= SCM_PTAB_ENTRY (port
);
109 /* I thought reading lines was simple. Mercy me. */
111 /* The common case: the buffer contains a complete line.
112 This needs to be fast. */
113 if ((end
= memchr (pt
->read_pos
, '\n', (pt
->read_end
- pt
->read_pos
)))
116 size_t buf_len
= (end
+ 1) - pt
->read_pos
;
117 /* Allocate a buffer of the perfect size. */
118 unsigned char *buf
= scm_malloc (buf_len
+ 1);
120 memcpy (buf
, pt
->read_pos
, buf_len
);
121 pt
->read_pos
+= buf_len
;
129 /* The buffer contains no newlines. */
131 /* When live, len is always the number of characters in the
132 current buffer that are part of the current line. */
133 size_t len
= (pt
->read_end
- pt
->read_pos
);
134 size_t buf_size
= (len
< 50) ? 60 : len
* 2;
135 /* Invariant: buf always has buf_size + 1 characters allocated;
136 the `+ 1' is for the final '\0'. */
137 unsigned char *buf
= scm_malloc (buf_size
+ 1);
142 if (buf_len
+ len
> buf_size
)
144 size_t new_size
= (buf_len
+ len
) * 2;
145 buf
= scm_realloc (buf
, new_size
+ 1);
149 /* Copy what we've got out of the port, into our buffer. */
150 memcpy (buf
+ buf_len
, pt
->read_pos
, len
);
154 /* If we had seen a newline, we're done now. */
158 /* Get more characters. */
159 if (scm_fill_input (port
) == EOF
)
161 /* If we're missing a final newline in the file, return
162 what we did get, sans newline. */
170 /* Search the buffer for newlines. */
171 if ((end
= memchr (pt
->read_pos
, '\n',
172 (len
= (pt
->read_end
- pt
->read_pos
))))
174 len
= (end
- pt
->read_pos
) + 1;
177 /* I wonder how expensive this realloc is. */
178 buf
= scm_realloc (buf
, buf_len
+ 1);
188 * truncates any terminating newline from its input, and returns
189 * a cons of the string read and its terminating character. Doing
190 * so makes it easy to implement the hairy `read-line' options
191 * efficiently in Scheme.
194 SCM_DEFINE (scm_read_line
, "%read-line", 0, 1, 0,
196 "Read a newline-terminated line from @var{port}, allocating storage as\n"
197 "necessary. The newline terminator (if any) is removed from the string,\n"
198 "and a pair consisting of the line and its delimiter is returned. The\n"
199 "delimiter may be either a newline or the @var{eof-object}; if\n"
200 "@code{%read-line} is called at the end of file, it returns the pair\n"
201 "@code{(#<eof> . #<eof>)}.")
202 #define FUNC_NAME s_scm_read_line
209 if (SCM_UNBNDP (port
))
210 port
= scm_current_input_port ();
211 SCM_VALIDATE_OPINPORT (1,port
);
213 pt
= SCM_PTAB_ENTRY (port
);
214 if (pt
->rw_active
== SCM_PORT_WRITE
)
215 scm_ptobs
[SCM_PTOBNUM (port
)].flush (port
);
217 s
= (char *) scm_do_read_line (port
, &slen
);
220 term
= line
= SCM_EOF_VAL
;
223 if (s
[slen
-1] == '\n')
225 term
= SCM_MAKE_CHAR ('\n');
227 line
= scm_take_locale_stringn (s
, slen
-1);
232 /* Fix: we should check for eof on the port before assuming this. */
234 line
= scm_take_locale_stringn (s
, slen
);
235 SCM_COL (port
) += slen
;
240 pt
->rw_active
= SCM_PORT_READ
;
242 return scm_cons (line
, term
);
246 SCM_DEFINE (scm_write_line
, "write-line", 1, 1, 0,
248 "Display @var{obj} and a newline character to @var{port}. If\n"
249 "@var{port} is not specified, @code{(current-output-port)} is\n"
250 "used. This function is equivalent to:\n"
252 "(display obj [port])\n"
255 #define FUNC_NAME s_scm_write_line
257 scm_display (obj
, port
);
258 return scm_newline (port
);
263 scm_init_rdelim_builtins (void)
265 #include "libguile/rdelim.x"
267 return SCM_UNSPECIFIED
;
271 scm_init_rdelim (void)
273 scm_c_define_gsubr ("%init-rdelim-builtins", 0, 0, 0,
274 scm_init_rdelim_builtins
);