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 opt_complementary = "-1";
46 noout = 1 & getopt32(argv, "xn:+m:+d:f:+", &ntokens, &mintokens, &delims, &flags);
50 t = xmalloc(sizeof(t[0]) * ntokens);
53 parser_t *p = config_open(*argv);
54 while ((n = config_read(p, t, ntokens, mintokens, delims, flags)) != 0) {
56 for (int i = 0; i < n; ++i)
68 parser_t* FAST_FUNC config_open2(const char *filename, FILE* FAST_FUNC (*fopen_func)(const char *path))
73 fp = fopen_func(filename);
76 parser = xzalloc(sizeof(*parser));
81 parser_t* FAST_FUNC config_open(const char *filename)
83 return config_open2(filename, fopen_or_warn_stdin);
86 void FAST_FUNC config_close(parser_t *parser)
89 if (PARSE_KEEP_COPY) /* compile-time constant */
98 /* This function reads an entire line from a text file,
99 * up to a newline, exclusive.
100 * Trailing '\' is recognized as line continuation.
101 * Returns -1 if EOF/error.
103 static int get_line_with_continuation(parser_t *parser)
108 len = getline(&parser->line, &parser->line_alloc, parser->fp);
115 if (line[len - 1] == '\n')
117 if (len == 0 || line[len - 1] != '\\')
121 nlen = getline(&parser->nline, &parser->nline_alloc, parser->fp);
125 if (parser->line_alloc < len + nlen + 1) {
126 parser->line_alloc = len + nlen + 1;
127 line = parser->line = xrealloc(line, parser->line_alloc);
129 memcpy(&line[len], parser->nline, nlen);
139 0. If parser is NULL return 0.
140 1. Read a line from config file. If nothing to read then return 0.
141 Handle continuation character. Advance lineno for each physical line.
142 Discard everything past comment character.
143 2. if PARSE_TRIM is set (default), remove leading and trailing delimiters.
144 3. If resulting line is empty goto 1.
145 4. Look for first delimiter. If !PARSE_COLLAPSE or !PARSE_TRIM is set then
146 remember the token as empty.
147 5. Else (default) if number of seen tokens is equal to max number of tokens
148 (token is the last one) and PARSE_GREEDY is set then the remainder
149 of the line is the last token.
150 Else (token is not last or PARSE_GREEDY is not set) just replace
151 first delimiter with '\0' thus delimiting the token.
152 6. Advance line pointer past the end of token. If number of seen tokens
153 is less than required number of tokens then goto 4.
154 7. Check the number of seen tokens is not less the min number of tokens.
155 Complain or die otherwise depending on PARSE_MIN_DIE.
156 8. Return the number of seen tokens.
158 mintokens > 0 make config_read() print error message if less than mintokens
159 (but more than 0) are found. Empty lines are always skipped (not warned about).
162 int FAST_FUNC config_read(parser_t *parser, char **tokens, unsigned flags, const char *delims)
165 int ntokens, mintokens;
171 ntokens = (uint8_t)flags;
172 mintokens = (uint8_t)(flags >> 8);
175 memset(tokens, 0, sizeof(tokens[0]) * ntokens);
177 /* Read one line (handling continuations with backslash) */
178 if (get_line_with_continuation(parser) < 0)
183 /* Skip token in the start of line? */
184 if (flags & PARSE_TRIM)
185 line += strspn(line, delims + 1);
187 if (line[0] == '\0' || line[0] == delims[0])
190 if (flags & PARSE_KEEP_COPY) {
192 parser->data = xstrdup(line);
195 /* Tokenize the line */
201 /* Combine remaining arguments? */
202 if ((t != (ntokens-1)) || !(flags & PARSE_GREEDY)) {
203 /* Vanilla token, find next delimiter */
204 line += strcspn(line, delims[0] ? delims : delims + 1);
206 /* Combining, find comment char if any */
207 line = strchrnul(line, PARSE_EOL_COMMENTS ? delims[0] : '\0');
209 /* Trim any extra delimiters from the end */
210 if (flags & PARSE_TRIM) {
211 while (strchr(delims + 1, line[-1]) != NULL)
216 /* Token not terminated? */
217 if (*line == delims[0])
219 else if (*line != '\0')
222 #if 0 /* unused so far */
223 if (flags & PARSE_ESCAPE) {
224 strcpy_and_process_escape_sequences(tokens[t], tokens[t]);
227 /* Skip possible delimiters */
228 if (flags & PARSE_COLLAPSE)
229 line += strspn(line, delims + 1);
232 } while (*line && *line != delims[0] && t < ntokens);
235 bb_error_msg("bad line %u: %d tokens found, %d needed",
236 parser->lineno, t, mintokens);
237 if (flags & PARSE_MIN_DIE)