Add support for a basic config file

1 files changed, 188 insertions, 0 deletions

diff --git a/src/ini.c b/src/ini.c
new file mode 100644
index 0000000..e4e734d
--- /dev/null
+++ b/src/ini.c
@@ -0,0 +1,188 @@
+#include "ini.h"
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+
+enum parse_state {
+  START,
+  READING_KEY,
+  SEEKING_EQ,
+  SEEKING_VALUE,
+  READING_VALUE,
+  READING_SECTION_KEY,
+  SEEKING_SECTION_VALUE,
+  SEEKING_END_SECTION,
+  READING_SECTION_VALUE,
+  ACCEPT,
+  REJECT
+};
+
+int parse_ini_file(FILE* f, char *out_key, size_t key_size, char *out_value, size_t value_size)
+{
+  char buf[512];
+  while(fgets(&buf[0], sizeof(buf), f)) {
+    int type = parse_ini_str(&buf[0], out_key, key_size, out_value, value_size);
+    if(type != 0) {
+      return type;
+    }
+  }
+  return 0;
+}
+
+int parse_ini_str(const char* str, char *out_key, size_t key_size, char *out_value, size_t value_size)
+{
+  /* ignore comments */
+  if(*str == ';') {
+    out_key[0] = 0;
+    out_value[0] = 0;
+    return INI_UNKNOWN;
+  }
+
+  const char *key_start = 0;
+  size_t key_len = 0;
+  const char *value_start = 0;
+  size_t value_len = 0;
+
+  int type = INI_UNKNOWN;
+  enum parse_state state = START;
+  char quote = 0;
+  char c = 0;
+
+  do {
+    c = *str;
+    switch(state) {
+      case START:
+        if(c == '[') {
+          type = INI_SECTION;
+          state = READING_SECTION_KEY;
+        } else if(c != '=') {
+          type = INI_VALUE;
+          state = READING_KEY;
+          key_start = str;
+          ++key_len;
+        } else {
+          state = REJECT;
+        }
+        break;
+      case READING_KEY:
+        if(isspace(c)) {
+          state = SEEKING_EQ;
+        } else if(c == '=') {
+          state = SEEKING_VALUE;
+        } else {
+          ++key_len;
+        }
+        break;
+      case SEEKING_EQ:
+        if(c == '=') {
+          state = SEEKING_VALUE;
+        } else if(!isspace(c)) {
+          state = REJECT;
+        }
+        break;
+      case SEEKING_VALUE:
+        if(c == '"' || c == '\'') {
+          if(!value_start) {
+            quote = c;
+            state = READING_VALUE;
+          } else {
+            state = REJECT;
+          }
+        } else if(!isspace(c)) {
+          value_start = str;
+          ++value_len;
+          state = READING_VALUE;
+        }
+        break;
+      case READING_VALUE:
+        if(quote == 0 && isspace(c)) {
+          state = ACCEPT;
+        } else if(quote && c == quote) {
+          state = ACCEPT;
+        } else if(c == 0) {
+          state = ACCEPT;
+        } else if(c) {
+          if(!value_start) {
+            value_start = str;
+          }
+          ++value_len;
+        } else {
+          state = REJECT;
+        }
+        break;
+      case READING_SECTION_KEY:
+        if(isspace(c)) {
+          state = SEEKING_SECTION_VALUE;
+        } else if(c == ']') {
+          state = ACCEPT;
+        } else {
+          if(!key_start) {
+            key_start = str;
+          }
+          ++key_len;
+        }
+        break;
+      case SEEKING_SECTION_VALUE:
+        if(c == '"' || c == '\'') {
+          quote = c;
+          state = READING_SECTION_VALUE;
+        } else if(c == ']') {
+          state = ACCEPT;
+        } else if(!isspace(c)) {
+          state = REJECT;
+        }
+        break;
+      case READING_SECTION_VALUE:
+        if(quote == 0 && isspace(c)) {
+          state = SEEKING_END_SECTION;
+        } else if(quote && c == quote) {
+          state = SEEKING_END_SECTION;
+        } else if(c == ']') {
+          state = ACCEPT;
+        } else if(c) {
+          if(!value_start) {
+            value_start = str;
+          }
+          ++value_len;
+        } else {
+          state = REJECT;
+        }
+        break;
+      case SEEKING_END_SECTION:
+        if(c == ']') {
+          state = ACCEPT;
+        } else if(!isspace(c)) {
+          state = REJECT;
+        }
+        break;
+      case ACCEPT:
+        if(c != 0 && !isspace(c)) {
+          state = REJECT;
+        }
+        break;
+      case REJECT:
+        return 0;
+        break;
+    }
+    ++str;
+  } while(c != 0 && state != REJECT);
+
+  if(state == ACCEPT) {
+    if(key_len >= key_size) {
+      key_len = key_size - 1;
+    }
+    if(value_len >= value_size) {
+      value_len = value_size - 1;
+    }
+    memcpy(out_key, key_start, key_len);
+    memcpy(out_value, value_start, value_len);
+    out_key[key_len] = 0;
+    out_value[value_len] = 0;
+    return type;
+  } else {
+    out_key[0] = 0;
+    out_value[0] = 0;
+  }
+
+  return INI_UNKNOWN;
+}