libbb: unified config parser (By Vladimir Dronnikov)
mdev: use it
function old new delta
config_read - 400 +400
config_open - 43 +43
config_close - 9 +9
qrealloc 33 36 +3
compare_keys 735 737 +2
xstrtoull_range_sfx 296 295 -1
qgravechar 109 106 -3
get_address 181 178 -3
next_token 928 923 -5
sv_main 1228 1222 -6
find_main 418 406 -12
next_field 32 - -32
make_device 1269 1184 -85
------------------------------------------------------------------------------
(add/remove: 3/1 grow/shrink: 2/7 up/down: 457/-147) Total: 310 bytes
diff --git a/libbb/parse_config.c b/libbb/parse_config.c
new file mode 100644
index 0000000..6612db3
--- /dev/null
+++ b/libbb/parse_config.c
@@ -0,0 +1,247 @@
+/* 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.
+ */
+
+#include "libbb.h"
+
+/*
+
+Typical usage:
+
+----- CUT -----
+ char *t[3]; // tokens placeholder
+ parser_t p; // parser structure
+ // open file
+ if (config_open(filename, &p)) {
+ // parse line-by-line
+ while (*config_read(&p, t, 3, 0, delimiters, comment_char)) { // 0..3 tokens
+ // use tokens
+ bb_error_msg("TOKENS: [%s][%s][%s]", t[0], t[1], t[2]);
+ }
+ ...
+ // free parser
+ config_close(&p);
+ }
+----- CUT -----
+
+*/
+
+#if !PARSER_STDIO_BASED
+
+char* FAST_FUNC config_open(parser_t *parser, const char *filename)
+{
+ // empty file configures nothing!
+ char *data = xmalloc_open_read_close(filename, NULL);
+ if (!data)
+ return data;
+
+ // convert 0x5c 0x0a (backslashes at the very end of line) to 0x20 0x20 (spaces)
+ for (char *s = data; (s = strchr(s, '\\')) != NULL; ++s)
+ if ('\n' == s[1]) {
+ s[0] = s[1] = ' ';
+ }
+
+ // init parser
+ parser->line = parser->data = data;
+ parser->lineno = 0;
+
+ return data;
+}
+
+void FAST_FUNC config_close(parser_t *parser)
+{
+ // for now just free config data
+ free(parser->data);
+}
+
+char* FAST_FUNC config_read(parser_t *parser, char **tokens, int ntokens, int mintokens, const char *delims, char comment)
+{
+ char *ret, *line;
+ int noreduce = (ntokens<0); // do not treat subsequent delimiters as one delimiter
+ if (ntokens < 0)
+ ntokens = -ntokens;
+ ret = line = parser->line;
+ // nullify tokens
+ memset(tokens, 0, sizeof(void *) * ntokens);
+ // now split to lines
+ while (*line) {
+ int token_num = 0;
+ // limit the line
+ char *ptr = strchrnul(line, '\n');
+ *ptr++ = '\0';
+ // line number
+ parser->lineno++;
+ // comments mean EOLs
+ if (comment)
+ *strchrnul(line, comment) = '\0';
+ // skip leading delimiters
+ while (*line && strchr(delims, *line))
+ line++;
+ // skip empty lines
+ if (*line) {
+ char *s;
+ // now split line to tokens
+ s = line;
+ while (s) {
+ char *p;
+ // get next token
+ if (token_num+1 >= ntokens)
+ break;
+ p = s;
+ while (*p && !strchr(delims, *p))
+ p++;
+ if (!*p)
+ break;
+ *p++ = '\0';
+ // pin token
+ if (noreduce || *s) {
+ tokens[token_num++] = s;
+//bb_error_msg("L[%d] T[%s]", token_num, s);
+ }
+ s = p;
+ }
+ // non-empty remainder is also a token. So if ntokens == 0, we just return the whole line
+ if (s && (noreduce || *s))
+ tokens[token_num++] = s;
+ // sanity check: have we got all required tokens?
+ if (token_num < mintokens)
+ bb_error_msg_and_die("bad line %u, %d tokens found, %d needed", parser->lineno, token_num, mintokens);
+ // advance data for the next call
+ line = ptr;
+ break;
+ }
+ // line didn't contain any token -> try next line
+ ret = line = ptr;
+ }
+ parser->line = line;
+
+ // return current line. caller must check *ret to determine whether to continue
+ return ret;
+}
+
+#else // stdio-based
+
+FILE* FAST_FUNC config_open(parser_t *parser, const char *filename)
+{
+ // empty file configures nothing!
+ parser->fp = fopen_or_warn(filename, "r");
+ if (!parser->fp)
+ return parser->fp;
+
+ // init parser
+ parser->line = NULL;
+ parser->lineno = 0;
+
+ return parser->fp;
+}
+
+void FAST_FUNC config_close(parser_t *parser)
+{
+ fclose(parser->fp);
+}
+
+char* FAST_FUNC config_read(parser_t *parser, char **tokens, int ntokens, int mintokens, const char *delims, char comment)
+{
+ char *line, *q;
+ int token_num, len;
+ int noreduce = (ntokens < 0); // do not treat subsequent delimiters as one delimiter
+
+ if (ntokens < 0)
+ ntokens = -ntokens;
+
+ // nullify tokens
+ memset(tokens, 0, sizeof(void *) * ntokens);
+
+ // free used line
+ free(parser->line);
+ parser->line = NULL;
+
+ while (1) {
+ int n;
+
+ // get fresh line
+//TODO: speed up xmalloc_fgetline by internally using fgets, not fgetc
+ line = xmalloc_fgetline(parser->fp);
+ if (!line)
+ return line;
+
+ parser->lineno++;
+ // handle continuations. Tito's code stolen :)
+ while (1) {
+ len = strlen(line);
+ if (!len)
+ goto free_and_cont;
+ if (line[len - 1] != '\\')
+ break;
+ // multi-line object
+ line[--len] = '\0';
+//TODO: add xmalloc_fgetline-like iface but with appending to existing str
+ q = xmalloc_fgetline(parser->fp);
+ if (q) {
+ parser->lineno++;
+ line = xasprintf("%s%s", line, q);
+ free(q);
+ }
+ }
+ // comments mean EOLs
+ if (comment) {
+ q = strchrnul(line, comment);
+ *q = '\0';
+ len = q - line;
+ }
+ // skip leading delimiters
+ n = strspn(line, delims);
+ if (n) {
+ len -= n;
+ strcpy(line, line + n);
+ }
+ if (len)
+ break;
+ // skip empty lines
+ free_and_cont:
+ free(line);
+ }
+
+ // non-empty line found, parse and return
+
+ // store line
+ parser->line = line = xrealloc(line, len + 1);
+
+ // now split line to tokens
+//TODO: discard consecutive delimiters?
+ token_num = 0;
+ ntokens--; // now it's max allowed token no
+ while (1) {
+ // get next token
+ if (token_num == ntokens)
+ break;
+ q = line + strcspn(line, delims);
+ if (!*q)
+ break;
+ // pin token
+ *q++ = '\0';
+ if (noreduce || *line) {
+ tokens[token_num++] = line;
+//bb_error_msg("L[%d] T[%s]", token_num, line);
+ }
+ line = q;
+ }
+
+ // non-empty remainder is also a token,
+ // so if ntokens <= 1, we just return the whole line
+ if (noreduce || *line)
+ tokens[token_num++] = line;
+
+ if (token_num < mintokens)
+ bb_error_msg_and_die("bad line %u: %d tokens found, %d needed",
+ parser->lineno, token_num, mintokens);
+
+ return parser->line; // maybe token_num instead?
+}
+
+#endif