1 /* readtokens.c -- Functions for reading tokens from an input stream.
3 Copyright (C) 1990-1991, 1999-2004, 2006, 2009-2011 Free Software
6 This program is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
19 Written by Jim Meyering. */
21 /* This almost supercedes xreadline stuff -- using delim="\n"
22 gives the same functionality, except that these functions
23 would never return empty lines. */
27 #include "readtokens.h"
37 # include "unlocked-io.h"
40 /* Initialize a tokenbuffer. */
43 init_tokenbuffer (token_buffer *tokenbuffer)
45 tokenbuffer->size = 0;
46 tokenbuffer->buffer = NULL;
49 /* Read a token from STREAM into TOKENBUFFER.
50 A token is delimited by any of the N_DELIM bytes in DELIM.
51 Upon return, the token is in tokenbuffer->buffer and
52 has a trailing '\0' instead of any original delimiter.
53 The function value is the length of the token not including
54 the final '\0'. Upon EOF (i.e. on the call after the last
55 token is read) or error, return -1 without modifying tokenbuffer.
56 The EOF and error conditions may be distinguished in the caller
57 by testing ferror (STREAM).
59 This function works properly on lines containing NUL bytes
60 and on files do not end with a delimiter. */
63 readtoken (FILE *stream,
66 token_buffer *tokenbuffer)
71 static const char *saved_delim = NULL;
72 static char isdelim[256];
75 if (delim == NULL && saved_delim == NULL)
78 same_delimiters = false;
79 if (delim != saved_delim && saved_delim != NULL)
81 same_delimiters = true;
82 for (i = 0; i < n_delim; i++)
84 if (delim[i] != saved_delim[i])
86 same_delimiters = false;
96 memset (isdelim, 0, sizeof isdelim);
97 for (j = 0; j < n_delim; j++)
99 unsigned char ch = delim[j];
104 /* FIXME: don't fool with this caching. Use strchr instead. */
105 /* skip over any leading delimiters */
106 for (c = getc (stream); c >= 0 && isdelim[c]; c = getc (stream))
111 p = tokenbuffer->buffer;
112 n = tokenbuffer->size;
120 p = x2nrealloc (p, &n, sizeof *p);
136 tokenbuffer->buffer = p;
137 tokenbuffer->size = n;
141 /* Build a NULL-terminated array of pointers to tokens
142 read from STREAM. Return the number of tokens read.
143 All storage is obtained through calls to xmalloc-like functions.
145 %%% Question: is it worth it to do a single
146 %%% realloc() of `tokens' just before returning? */
149 readtokens (FILE *stream,
150 size_t projected_n_tokens,
154 size_t **token_lengths)
156 token_buffer tb, *token = &tb;
162 if (projected_n_tokens == 0)
163 projected_n_tokens = 64;
165 projected_n_tokens++; /* add one for trailing NULL pointer */
167 sz = projected_n_tokens;
168 tokens = xnmalloc (sz, sizeof *tokens);
169 lengths = xnmalloc (sz, sizeof *lengths);
172 init_tokenbuffer (token);
176 size_t token_length = readtoken (stream, delim, n_delim, token);
179 tokens = x2nrealloc (tokens, &sz, sizeof *tokens);
180 lengths = xnrealloc (lengths, sz, sizeof *lengths);
183 if (token_length == (size_t) -1)
185 /* don't increment n_tokens for NULL entry */
186 tokens[n_tokens] = NULL;
187 lengths[n_tokens] = 0;
190 tmp = xnmalloc (token_length + 1, sizeof *tmp);
191 lengths[n_tokens] = token_length;
192 tokens[n_tokens] = memcpy (tmp, token->buffer, token_length + 1);
196 free (token->buffer);
197 *tokens_out = tokens;
198 if (token_lengths != NULL)
199 *token_lengths = lengths;