Import code to load configuration from file.

WARNING: This commit do not contains a fully cleaned code:
 - Only nfc-list have been tested
 - Some -commented- code is not used ATM
 - Some printf-as-debug remain in this commit
... but that a bit usable so... happy hacking ;-)

libnfc/conf.c

@@ -0,0 +1,131 @@
+/*-
+ * Copyright (C) 2012 Romuald Conty
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <string.h>
+#include <regex.h>
+#include <sys/stat.h>
+
+#include <nfc/nfc.h>
+#include "nfc-internal.h"
+#include "log.h"
+
+#define LOG_CATEGORY "libnfc.config"
+
+#define LIBNFC_SYSCONFDIR      "/etc/nfc"
+#define LIBNFC_CONFFILE        LIBNFC_SYSCONFDIR"/libnfc.conf"
+#define LIBNFC_DEVICECONFDIR   LIBNFC_SYSCONFDIR"/devices.d"
+
+
+bool conf_parse_file(const char* filename, void (*conf_keyvalue)(void* data, const char* key, const char* value), void* data)
+{
+  FILE *f = fopen (filename, "r");
+  if (!f) {
+    perror ("fopen");
+    return false;
+  }
+  char line[BUFSIZ];
+  const char *str_regex = "^[[:space:]]*([[:alnum:]_]+)[[:space:]]*=[[:space:]]*(\"(.+)\"|([^[:space:]]+))[[:space:]]*$";
+  regex_t preg;
+  if(regcomp (&preg, str_regex, REG_EXTENDED|REG_NOTEOL) != 0) {
+    printf ("regcomp error\n");
+    return false;
+  }
+  size_t nmatch = preg.re_nsub + 1;
+  regmatch_t *pmatch = malloc (sizeof (*pmatch) * nmatch);
+  if(!pmatch) {
+    perror ("malloc");
+    return false;
+  }
+
+  int lineno = 0;
+  while (fgets(line, BUFSIZ, f) != NULL) {
+    lineno++;
+    switch(line[0]) {
+      case '#':
+      case '\n':
+        break;
+      default: {
+        int match;
+        if ((match = regexec (&preg, line, nmatch, pmatch, 0)) == 0) {
+          const size_t key_size = pmatch[1].rm_eo - pmatch[1].rm_so;
+          const off_t  value_pmatch = pmatch[3].rm_eo!=-1?3:4;
+          const size_t value_size = pmatch[value_pmatch].rm_eo - pmatch[value_pmatch].rm_so;
+          char key[key_size+1];
+          char value[value_size+1];
+          strncpy(key, line+(pmatch[1].rm_so), key_size); key[key_size]='\0';
+          strncpy(value, line+(pmatch[value_pmatch].rm_so), value_size); value[value_size]='\0';
+          conf_keyvalue(data, key, value);
+        } else {
+          log_put( LOG_CATEGORY, NFC_PRIORITY_TRACE, "parse error on line #%d: %s", lineno, line);
+        }
+      }
+      break;
+    }
+  }
+  return false;
+}
+
+void 
+conf_keyvalue_context(void *data, const char* key, const char* value)
+{
+  nfc_context *context = (nfc_context*)data;
+  printf ("key: [%s], value: [%s]\n", key, value);
+  if (strcmp(key, "allow_autoscan") == 0) {
+    string_as_boolean(value, &(context->allow_autoscan));
+  } else if (strcmp(key, "allow_intrusive_scan") == 0) {
+    string_as_boolean(value, &(context->allow_intrusive_scan));
+  } else {
+    log_put( LOG_CATEGORY, NFC_PRIORITY_INFO, "unknown key in config line: %s = %s", key, value);
+  }
+}
+
+void 
+conf_load(nfc_context *context)
+{
+  conf_parse_file(LIBNFC_CONFFILE, conf_keyvalue_context, context);
+}
+
+/*
+int 
+main(int argc, char *argv[])
+{
+  DIR *d = opendir(LIBNFC_DEVICECONFDIR);
+  if (!d) {
+    perror ("opendir");
+  } else {
+    struct dirent* de;
+    while (de = readdir(d)) {
+      if (de->d_name[0]!='.') {
+        printf ("\t%s\n", de->d_name);
+        char filename[BUFSIZ] = LIBNFC_DEVICECONFDIR"/";
+        strcat (filename, de->d_name);
+        struct stat s;
+        if (stat(filename, &s) == -1) {
+          perror("stat");
+          continue;
+        }
+        if(S_ISREG(s.st_mode)) {
+          nfc_open_from_file (filename);
+        }
+      }
+    }
+  }
+}
+*/