1 /* readtokens.c -- Functions for reading tokens from an input stream.
3 Copyright (C) 1990-1991, 1999-2004, 2006, 2009 Free Software Foundation, Inc.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
18 Written by Jim Meyering. */
20 /* This almost supercedes xreadline stuff -- using delim="\n"
21 gives the same functionality, except that these functions
22 would never return empty lines. */
26 #include "readtokens.h"
36 # include "unlocked-io.h"
39 /* Initialize a tokenbuffer. */
42 init_tokenbuffer (token_buffer *tokenbuffer)
44 tokenbuffer->size = 0;
45 tokenbuffer->buffer = NULL;
48 /* Read a token from STREAM into TOKENBUFFER.
49 A token is delimited by any of the N_DELIM bytes in DELIM.
50 Upon return, the token is in tokenbuffer->buffer and
51 has a trailing '\0' instead of any original delimiter.
52 The function value is the length of the token not including
53 the final '\0'. Upon EOF (i.e. on the call after the last
54 token is read) or error, return -1 without modifying tokenbuffer.
55 The EOF and error conditions may be distinguished in the caller
56 by testing ferror (STREAM).
58 This function works properly on lines containing NUL bytes
59 and on files do not end with a delimiter. */
62 readtoken (FILE *stream,
65 token_buffer *tokenbuffer)
70 static const char *saved_delim = NULL;
71 static char isdelim[256];
74 if (delim == NULL && saved_delim == NULL)
77 same_delimiters = false;
78 if (delim != saved_delim && saved_delim != NULL)
80 same_delimiters = true;
81 for (i = 0; i < n_delim; i++)
83 if (delim[i] != saved_delim[i])
85 same_delimiters = false;
95 memset (isdelim, 0, sizeof isdelim);
96 for (j = 0; j < n_delim; j++)
98 unsigned char ch = delim[j];
103 /* FIXME: don't fool with this caching. Use strchr instead. */
104 /* skip over any leading delimiters */
105 for (c = getc (stream); c >= 0 && isdelim[c]; c = getc (stream))
110 p = tokenbuffer->buffer;
111 n = tokenbuffer->size;
119 p = x2nrealloc (p, &n, sizeof *p);
135 tokenbuffer->buffer = p;
136 tokenbuffer->size = n;
140 /* Build a NULL-terminated array of pointers to tokens
141 read from STREAM. Return the number of tokens read.
142 All storage is obtained through calls to xmalloc-like functions.
144 %%% Question: is it worth it to do a single
145 %%% realloc() of `tokens' just before returning? */
148 readtokens (FILE *stream,
149 size_t projected_n_tokens,
153 size_t **token_lengths)
155 token_buffer tb, *token = &tb;
161 if (projected_n_tokens == 0)
162 projected_n_tokens = 64;
164 projected_n_tokens++; /* add one for trailing NULL pointer */
166 sz = projected_n_tokens;
167 tokens = xnmalloc (sz, sizeof *tokens);
168 lengths = xnmalloc (sz, sizeof *lengths);
171 init_tokenbuffer (token);
175 size_t token_length = readtoken (stream, delim, n_delim, token);
178 tokens = x2nrealloc (tokens, &sz, sizeof *tokens);
179 lengths = xnrealloc (lengths, sz, sizeof *lengths);
182 if (token_length == (size_t) -1)
184 /* don't increment n_tokens for NULL entry */
185 tokens[n_tokens] = NULL;
186 lengths[n_tokens] = 0;
189 tmp = xnmalloc (token_length + 1, sizeof *tmp);
190 lengths[n_tokens] = token_length;
191 tokens[n_tokens] = memcpy (tmp, token->buffer, token_length + 1);
195 free (token->buffer);
196 *tokens_out = tokens;
197 if (token_lengths != NULL)
198 *token_lengths = lengths;