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
66 SCM_VALIDATE_STRING (1, delims
);
67 cdelims
= scm_i_string_chars (delims
);
68 num_delims
= scm_i_string_length (delims
);
70 SCM_VALIDATE_STRING (2, str
);
71 scm_i_get_substring_spec (scm_i_string_length (str
),
72 start
, &cstart
, end
, &cend
);
74 if (SCM_UNBNDP (port
))
75 port
= scm_current_input_port ();
77 SCM_VALIDATE_OPINPORT (4, port
);
79 for (j
= cstart
; j
< cend
; j
++)
84 for (k
= 0; k
< num_delims
; k
++)
88 if (scm_is_false (gobble
))
91 return scm_cons (SCM_MAKE_CHAR (c
),
92 scm_from_size_t (j
- cstart
));
96 return scm_cons (SCM_EOF_VAL
,
97 scm_from_size_t (j
- cstart
));
99 scm_c_string_set_x (str
, j
, SCM_MAKE_CHAR (c
));
101 return scm_cons (SCM_BOOL_F
, scm_from_size_t (j
- cstart
));
105 static unsigned char *
106 scm_do_read_line (SCM port
, size_t *len_p
)
108 scm_t_port
*pt
= SCM_PTAB_ENTRY (port
);
111 /* I thought reading lines was simple. Mercy me. */
113 /* The common case: the buffer contains a complete line.
114 This needs to be fast. */
115 if ((end
= memchr (pt
->read_pos
, '\n', (pt
->read_end
- pt
->read_pos
)))
118 size_t buf_len
= (end
+ 1) - pt
->read_pos
;
119 /* Allocate a buffer of the perfect size. */
120 unsigned char *buf
= scm_malloc (buf_len
+ 1);
122 memcpy (buf
, pt
->read_pos
, buf_len
);
123 pt
->read_pos
+= buf_len
;
131 /* The buffer contains no newlines. */
133 /* When live, len is always the number of characters in the
134 current buffer that are part of the current line. */
135 size_t len
= (pt
->read_end
- pt
->read_pos
);
136 size_t buf_size
= (len
< 50) ? 60 : len
* 2;
137 /* Invariant: buf always has buf_size + 1 characters allocated;
138 the `+ 1' is for the final '\0'. */
139 unsigned char *buf
= scm_malloc (buf_size
+ 1);
144 if (buf_len
+ len
> buf_size
)
146 size_t new_size
= (buf_len
+ len
) * 2;
147 buf
= scm_realloc (buf
, new_size
+ 1);
151 /* Copy what we've got out of the port, into our buffer. */
152 memcpy (buf
+ buf_len
, pt
->read_pos
, len
);
156 /* If we had seen a newline, we're done now. */
160 /* Get more characters. */
161 if (scm_fill_input (port
) == EOF
)
163 /* If we're missing a final newline in the file, return
164 what we did get, sans newline. */
172 /* Search the buffer for newlines. */
173 if ((end
= memchr (pt
->read_pos
, '\n',
174 (len
= (pt
->read_end
- pt
->read_pos
))))
176 len
= (end
- pt
->read_pos
) + 1;
179 /* I wonder how expensive this realloc is. */
180 buf
= scm_realloc (buf
, buf_len
+ 1);
190 * truncates any terminating newline from its input, and returns
191 * a cons of the string read and its terminating character. Doing
192 * so makes it easy to implement the hairy `read-line' options
193 * efficiently in Scheme.
196 SCM_DEFINE (scm_read_line
, "%read-line", 0, 1, 0,
198 "Read a newline-terminated line from @var{port}, allocating storage as\n"
199 "necessary. The newline terminator (if any) is removed from the string,\n"
200 "and a pair consisting of the line and its delimiter is returned. The\n"
201 "delimiter may be either a newline or the @var{eof-object}; if\n"
202 "@code{%read-line} is called at the end of file, it returns the pair\n"
203 "@code{(#<eof> . #<eof>)}.")
204 #define FUNC_NAME s_scm_read_line
211 if (SCM_UNBNDP (port
))
212 port
= scm_current_input_port ();
213 SCM_VALIDATE_OPINPORT (1,port
);
215 pt
= SCM_PTAB_ENTRY (port
);
216 if (pt
->rw_active
== SCM_PORT_WRITE
)
217 scm_ptobs
[SCM_PTOBNUM (port
)].flush (port
);
219 s
= (char *) scm_do_read_line (port
, &slen
);
222 term
= line
= SCM_EOF_VAL
;
225 if (s
[slen
-1] == '\n')
227 term
= SCM_MAKE_CHAR ('\n');
229 line
= scm_take_locale_stringn (s
, slen
-1);
234 /* Fix: we should check for eof on the port before assuming this. */
236 line
= scm_take_locale_stringn (s
, slen
);
237 SCM_COL (port
) += slen
;
242 pt
->rw_active
= SCM_PORT_READ
;
244 return scm_cons (line
, term
);
248 SCM_DEFINE (scm_write_line
, "write-line", 1, 1, 0,
250 "Display @var{obj} and a newline character to @var{port}. If\n"
251 "@var{port} is not specified, @code{(current-output-port)} is\n"
252 "used. This function is equivalent to:\n"
254 "(display obj [port])\n"
257 #define FUNC_NAME s_scm_write_line
259 scm_display (obj
, port
);
260 return scm_newline (port
);
265 scm_init_rdelim_builtins (void)
267 #include "libguile/rdelim.x"
269 return SCM_UNSPECIFIED
;
273 scm_init_rdelim (void)
275 scm_c_define_gsubr ("%init-rdelim-builtins", 0, 0, 0,
276 scm_init_rdelim_builtins
);