1 /* vi: set sw=4 ts=4: */
3 * config file parser helper
5 * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8 * Also for use in uClibc (http://uclibc.org/) licensed under LGPLv2.1 or later.
11 /* Uncomment to enable test applet */
12 ////config:config PARSE
13 ////config: bool "Uniform config file parser debugging applet: parse"
16 ////config: Typical usage of parse API:
17 ////config: char *t[3];
18 ////config: parser_t *p = config_open(filename);
19 ////config: while (config_read(p, t, 3, 0, delimiters, flags)) { // 1..3 tokens
20 ////config: bb_error_msg("TOKENS: '%s''%s''%s'", t[0], t[1], t[2]);
22 ////config: config_close(p);
24 ////applet:IF_PARSE(APPLET(parse, BB_DIR_USR_BIN, BB_SUID_DROP))
26 //kbuild:lib-y += parse_config.o
28 //usage:#define parse_trivial_usage
29 //usage: "[-x] [-n MAXTOKENS] [-m MINTOKENS] [-d DELIMS] [-f FLAGS] FILE..."
30 //usage:#define parse_full_usage "\n\n"
31 //usage: " -x Suppress output (for benchmarking)"
35 #if defined ENABLE_PARSE && ENABLE_PARSE
36 int parse_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
37 int parse_main(int argc UNUSED_PARAM, char **argv)
39 const char *delims = "# \t";
41 unsigned flags = PARSE_NORMAL;
42 int mintokens = 0, ntokens = 128;
45 noout = 1 & getopt32(argv, "^" "xn:+m:+d:f:+" "\0" "-1",
46 &ntokens, &mintokens, &delims, &flags
51 t = xmalloc(sizeof(t[0]) * ntokens);
54 parser_t *p = config_open(*argv);
55 while ((n = config_read(p, t, ntokens, mintokens, delims, flags)) != 0) {
57 for (int i = 0; i < n; ++i)
69 parser_t* FAST_FUNC config_open2(const char *filename, FILE* FAST_FUNC (*fopen_func)(const char *path))
74 fp = fopen_func(filename);
77 parser = xzalloc(sizeof(*parser));
82 parser_t* FAST_FUNC config_open(const char *filename)
84 return config_open2(filename, fopen_or_warn_stdin);
87 void FAST_FUNC config_close(parser_t *parser)
90 if (PARSE_KEEP_COPY) /* compile-time constant */
99 /* This function reads an entire line from a text file,
100 * up to a newline, exclusive.
101 * Trailing '\' is recognized as line continuation.
102 * Returns -1 if EOF/error.
104 static int get_line_with_continuation(parser_t *parser)
109 len = getline(&parser->line, &parser->line_alloc, parser->fp);
116 if (line[len - 1] == '\n')
118 if (len == 0 || line[len - 1] != '\\')
122 nlen = getline(&parser->nline, &parser->nline_alloc, parser->fp);
126 if (parser->line_alloc < len + nlen + 1) {
127 parser->line_alloc = len + nlen + 1;
128 line = parser->line = xrealloc(line, parser->line_alloc);
130 memcpy(&line[len], parser->nline, nlen);
140 0. If parser is NULL return 0.
141 1. Read a line from config file. If nothing to read then return 0.
142 Handle continuation character. Advance lineno for each physical line.
143 Discard everything past comment character.
144 2. if PARSE_TRIM is set (default), remove leading and trailing delimiters.
145 3. If resulting line is empty goto 1.
146 4. Look for first delimiter. If !PARSE_COLLAPSE or !PARSE_TRIM is set then
147 remember the token as empty.
148 5. Else (default) if number of seen tokens is equal to max number of tokens
149 (token is the last one) and PARSE_GREEDY is set then the remainder
150 of the line is the last token.
151 Else (token is not last or PARSE_GREEDY is not set) just replace
152 first delimiter with '\0' thus delimiting the token.
153 6. Advance line pointer past the end of token. If number of seen tokens
154 is less than required number of tokens then goto 4.
155 7. Check the number of seen tokens is not less the min number of tokens.
156 Complain or die otherwise depending on PARSE_MIN_DIE.
157 8. Return the number of seen tokens.
159 mintokens > 0 make config_read() print error message if less than mintokens
160 (but more than 0) are found. Empty lines are always skipped (not warned about).
163 int FAST_FUNC config_read(parser_t *parser, char **tokens, unsigned flags, const char *delims)
166 int ntokens, mintokens;
173 alt_comment_ch = '\0';
174 if (flags & PARSE_ALT_COMMENTS)
175 alt_comment_ch = *delims++;
177 ntokens = (uint8_t)flags;
178 mintokens = (uint8_t)(flags >> 8);
181 memset(tokens, 0, sizeof(tokens[0]) * ntokens);
183 /* Read one line (handling continuations with backslash) */
184 if (get_line_with_continuation(parser) < 0)
189 /* Skip token in the start of line? */
190 if (flags & PARSE_TRIM)
191 line += strspn(line, delims + 1);
194 if (flags & PARSE_WS_COMMENTS)
195 p = skip_whitespace(p);
196 if (p[0] == '\0' || p[0] == delims[0] || p[0] == alt_comment_ch)
199 if (flags & PARSE_KEEP_COPY) {
201 parser->data = xstrdup(line);
204 /* Tokenize the line */
210 /* Combine remaining arguments? */
211 if ((t != (ntokens-1)) || !(flags & PARSE_GREEDY)) {
212 /* Vanilla token, find next delimiter */
213 line += strcspn(line, (delims[0] && (flags & PARSE_EOL_COMMENTS)) ? delims : delims + 1);
215 /* Combining, find comment char if any */
216 line = strchrnul(line, (flags & PARSE_EOL_COMMENTS) ? delims[0] : '\0');
218 /* Trim any extra delimiters from the end */
219 if (flags & PARSE_TRIM) {
220 while (strchr(delims + 1, line[-1]) != NULL)
225 /* Token not terminated? */
226 if ((flags & PARSE_EOL_COMMENTS) && *line == delims[0])
227 *line = '\0'; /* ends with comment char: this line is done */
228 else if (*line != '\0')
229 *line++ = '\0'; /* token is done, continue parsing line */
231 #if 0 /* unused so far */
232 if (flags & PARSE_ESCAPE) {
233 strcpy_and_process_escape_sequences(tokens[t], tokens[t]);
236 /* Skip possible delimiters */
237 if (flags & PARSE_COLLAPSE)
238 line += strspn(line, delims + 1);
241 } while (*line && *line != delims[0] && t < ntokens);
244 bb_error_msg("bad line %u: %d tokens found, %d needed",
245 parser->lineno, t, mintokens);
246 if (flags & PARSE_MIN_DIE)