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authorBernhard Reutner-Fischer <rep.dot.nop@gmail.com>2010-01-17 17:07:22 +0100
committerBernhard Reutner-Fischer <rep.dot.nop@gmail.com>2010-08-05 23:42:40 +0200
commit8faa445d364dda147146e2036f6460a5347736f0 (patch)
tree70b046425e9b88d95cfaf2742b670784a1c2967f /libc/misc/internals/parse_config.c
parent6ff4fcbfe507605b2796eb8e7e44c7e8e4b33a28 (diff)
add config parser
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
Diffstat (limited to 'libc/misc/internals/parse_config.c')
-rw-r--r--libc/misc/internals/parse_config.c268
1 files changed, 268 insertions, 0 deletions
diff --git a/libc/misc/internals/parse_config.c b/libc/misc/internals/parse_config.c
new file mode 100644
index 000000000..cbb6ef7f1
--- /dev/null
+++ b/libc/misc/internals/parse_config.c
@@ -0,0 +1,268 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * config file parser helper
+ *
+ * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Also for use in uClibc (http://uclibc.org/) licensed under LGPLv2.1 or later.
+ */
+
+#if !defined _LIBC
+#include "libbb.h"
+
+#if defined ENABLE_PARSE && ENABLE_PARSE
+int parse_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int parse_main(int argc UNUSED_PARAM, char **argv)
+{
+ const char *delims = "# \t";
+ unsigned flags = PARSE_NORMAL;
+ int mintokens = 0, ntokens = 128;
+
+ opt_complementary = "-1:n+:m+:f+";
+ getopt32(argv, "n:m:d:f:", &ntokens, &mintokens, &delims, &flags);
+ //argc -= optind;
+ argv += optind;
+ while (*argv) {
+ parser_t *p = config_open(*argv);
+ if (p) {
+ int n;
+ char **t = xmalloc(sizeof(char *) * ntokens);
+ while ((n = config_read(p, t, ntokens, mintokens, delims, flags)) != 0) {
+ for (int i = 0; i < n; ++i)
+ printf("[%s]", t[i]);
+ puts("");
+ }
+ config_close(p);
+ }
+ argv++;
+ }
+ return EXIT_SUCCESS;
+}
+#endif
+#else
+# include <unistd.h>
+# include <string.h>
+# include <malloc.h>
+# include "internal/parse_config.h"
+# ifndef FAST_FUNC
+# define FAST_FUNC
+# endif
+# define fopen_or_warn_stdin fopen
+# define bb_error_msg(...)
+# define xstrdup strdup
+# define xfunc_die() return 0
+/* Read up to EOF or EOL, treat line-continuations as extending the line.
+ Return number of bytes read into .line, -1 otherwise */
+static off_t bb_get_chunk_with_continuation(parser_t* parsr)
+{
+ off_t pos = 0;
+ char *chp;
+
+ while (1) {
+ if (fgets(parsr->line + pos, parsr->line_len, parsr->fp) == NULL) {
+ memset(parsr->line, 0, parsr->line_len);
+ pos = -1;
+ break;
+ }
+ pos += strlen(parsr->line + pos);
+ chp = strchr(parsr->line, '\n');
+ if (chp) {
+ --pos;
+ if (--*chp == '\\')
+ --pos;
+ else
+ break;
+ }
+ }
+ return pos;
+}
+#endif
+
+/*
+
+Typical usage:
+
+----- CUT -----
+ char *t[3]; // tokens placeholder
+ parser_t *p = config_open(filename);
+ if (p) {
+ // parse line-by-line
+ while (config_read(p, t, 3, 0, delimiters, flags)) { // 1..3 tokens
+ // use tokens
+ bb_error_msg("TOKENS: [%s][%s][%s]", t[0], t[1], t[2]);
+ }
+ ...
+ // free parser
+ config_close(p);
+ }
+----- CUT -----
+
+*/
+
+static __always_inline parser_t * FAST_FUNC config_open2(const char *filename,
+ FILE* FAST_FUNC (*fopen_func)(const char *path, const char *mode))
+{
+ parser_t *parser;
+ FILE* fp;
+
+ fp = fopen_func(filename, "r");
+ if (!fp)
+ return NULL;
+ parser = malloc(sizeof(*parser));
+ if (parser) {
+ memset(parser, 0, sizeof(*parser));
+ parser->fp = fp;
+ }
+ return parser;
+}
+
+parser_t attribute_hidden * FAST_FUNC config_open(const char *filename)
+{
+ return config_open2(filename, fopen_or_warn_stdin);
+}
+
+#ifdef UNUSED
+static void config_free_data(parser_t *parser)
+{
+ free(parser->data);
+ parser->data = parser->line = NULL;
+}
+#endif
+
+void attribute_hidden FAST_FUNC config_close(parser_t *parser)
+{
+ if (parser) {
+ fclose(parser->fp);
+ if (parser->allocated)
+ free(parser->data);
+ free(parser);
+ }
+}
+
+/*
+0. If parser is NULL return 0.
+1. Read a line from config file. If nothing to read then return 0.
+ Handle continuation character. Advance lineno for each physical line.
+ Discard everything past comment character.
+2. if PARSE_TRIM is set (default), remove leading and trailing delimiters.
+3. If resulting line is empty goto 1.
+4. Look for first delimiter. If !PARSE_COLLAPSE or !PARSE_TRIM is set then
+ remember the token as empty.
+5. Else (default) if number of seen tokens is equal to max number of tokens
+ (token is the last one) and PARSE_GREEDY is set then the remainder
+ of the line is the last token.
+ Else (token is not last or PARSE_GREEDY is not set) just replace
+ first delimiter with '\0' thus delimiting the token.
+6. Advance line pointer past the end of token. If number of seen tokens
+ is less than required number of tokens then goto 4.
+7. Check the number of seen tokens is not less the min number of tokens.
+ Complain or die otherwise depending on PARSE_MIN_DIE.
+8. Return the number of seen tokens.
+
+mintokens > 0 make config_read() print error message if less than mintokens
+(but more than 0) are found. Empty lines are always skipped (not warned about).
+*/
+#undef config_read
+int attribute_hidden FAST_FUNC config_read(parser_t *parser, char ***tokens,
+ unsigned flags, const char *delims)
+{
+ char *line;
+ int ntokens, mintokens;
+ off_t len;
+ int t;
+
+ if (parser == NULL)
+ return 0;
+ ntokens = flags & 0xFF;
+ mintokens = (flags & 0xFF00) >> 8;
+again:
+ if (parser->data == NULL) {
+ if (parser->line_len == 0)
+ parser->line_len = 81;
+ if (parser->data_len == 0)
+ parser->data_len += 1 + ntokens * sizeof(char *);
+ parser->data = realloc(parser->data,
+ parser->data_len + parser->line_len);
+ if (parser->data == NULL)
+ return 0;
+ parser->allocated |= 1;
+ } /* else { assert(parser->data_len > 0); } */
+ if (parser->line == NULL)
+ parser->line = parser->data + parser->data_len;
+ if (*tokens == NULL)
+ *tokens = (char **) parser->data;
+ memset(*tokens, 0, sizeof(*tokens[0]) * ntokens);
+ /*config_free_data(parser);*/
+
+ /* Read one line (handling continuations with backslash) */
+ len = bb_get_chunk_with_continuation(parser);
+ if (len == -1)
+ return 0;
+ line = parser->line;
+
+ /* Skip token in the start of line? */
+ if (flags & PARSE_TRIM)
+ line += strspn(line, delims + 1);
+
+ if (line[0] == '\0' || line[0] == delims[0])
+ goto again;
+
+ /* Tokenize the line */
+ for (t = 0; *line && *line != delims[0] && t < ntokens; t++) {
+ /* Pin token */
+ *(*tokens + t) = line;
+
+ /* Combine remaining arguments? */
+ if ((t != ntokens-1) || !(flags & PARSE_GREEDY)) {
+ /* Vanilla token, find next delimiter */
+ line += strcspn(line, delims[0] ? delims : delims + 1);
+ } else {
+ /* Combining, find comment char if any */
+ line = strchrnul(line, delims[0]);
+
+ /* Trim any extra delimiters from the end */
+ if (flags & PARSE_TRIM) {
+ while (strchr(delims + 1, line[-1]) != NULL)
+ line--;
+ }
+ }
+
+ /* Token not terminated? */
+ if (line[0] == delims[0])
+ *line = '\0';
+ else if (line[0] != '\0')
+ *(line++) = '\0';
+
+#if 0 /* unused so far */
+ if (flags & PARSE_ESCAPE) {
+ const char *from;
+ char *to;
+
+ from = to = tokens[t];
+ while (*from) {
+ if (*from == '\\') {
+ from++;
+ *to++ = bb_process_escape_sequence(&from);
+ } else {
+ *to++ = *from++;
+ }
+ }
+ *to = '\0';
+ }
+#endif
+
+ /* Skip possible delimiters */
+ if (flags & PARSE_COLLAPSE)
+ line += strspn(line, delims + 1);
+ }
+
+ if (t < mintokens) {
+ bb_error_msg(/*"bad line %u: "*/"%d tokens found, %d needed",
+ /*parser->lineno, */t, mintokens);
+ if (flags & PARSE_MIN_DIE)
+ xfunc_die();
+ goto again;
+ }
+ return t;
+}