Adding parser.c and parser.h used for parsing of moxanix config files. Actual parsing not yet implemented.

parser.c

@@ -0,0 +1,147 @@
+/* 
+ * simple .INI file parser
+ */
+
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+
+#include "parser.h"
+
+#define MAX_SECTION 50
+#define MAX_NAME 50
+
+/* Strip whitespace chars off end of given string, in place. Return s. */
+static char* rstrip(char* s)
+{
+    char* p = s + strlen(s);
+    while (p > s && isspace((unsigned char)(*--p)))
+        *p = '\0';
+    return s;
+}
+
+/* Return pointer to first non-whitespace char in given string. */
+static char* lskip(const char* s)
+{
+    while (*s && isspace((unsigned char)(*s)))
+        s++;
+    return (char*)s;
+}
+
+/* Return pointer to first char c or ';' comment in given string, or pointer to
+   null at end of string if neither found. ';' must be prefixed by a whitespace
+   character to register as a comment. */
+static char* find_char_or_comment(const char* s, char c)
+{
+    int was_whitespace = 0;
+    while (*s && *s != c && !(was_whitespace && *s == ';')) {
+        was_whitespace = isspace((unsigned char)(*s));
+        s++;
+    }
+    return (char*)s;
+}
+
+/* Version of strncpy that ensures dest (size bytes) is null-terminated. */
+static char* strncpy0(char* dest, const char* src, size_t size)
+{
+    strncpy(dest, src, size);
+    dest[size - 1] = '\0';
+    return dest;
+}
+
+/* See documentation in header file. */
+int ini_parse_file(FILE* file,
+                   int (*handler)(void*, const char*, const char*,
+                                  const char*),
+                   void* user)
+{
+    /* Uses a fair bit of stack (use heap instead if you need to) */
+    char line[INI_MAX_LINE];
+    char section[MAX_SECTION] = "";
+    char prev_name[MAX_NAME] = "";
+
+    char* start;
+    char* end;
+    char* name;
+    char* value;
+    int lineno = 0;
+    int error = 0;
+
+    /* Scan through file line by line */
+    while (fgets(line, INI_MAX_LINE, file) != NULL) {
+        lineno++;
+
+        start = line;
+#if INI_ALLOW_BOM
+        if (lineno == 1 && (unsigned char)start[0] == 0xEF &&
+                           (unsigned char)start[1] == 0xBB &&
+                           (unsigned char)start[2] == 0xBF) {
+            start += 3;
+        }
+#endif
+        start = lskip(rstrip(start));
+
+        if (*start == ';' || *start == '#') {
+            /* Per Python ConfigParser, allow '#' comments at start of line */
+        }
+        else if (*start == '[') {
+            /* A "[section]" line */
+            end = find_char_or_comment(start + 1, ']');
+            if (*end == ']') {
+                *end = '\0';
+                strncpy0(section, start + 1, sizeof(section));
+                *prev_name = '\0';
+            }
+            else if (!error) {
+                /* No ']' found on section line */
+                error = lineno;
+            }
+        }
+        else if (*start && *start != ';') {
+            /* Not a comment, must be a name[=:]value pair */
+            end = find_char_or_comment(start, '=');
+            if (*end != '=') {
+                end = find_char_or_comment(start, ':');
+            }
+            if (*end == '=' || *end == ':') {
+                *end = '\0';
+                name = rstrip(start);
+                value = lskip(end + 1);
+                end = find_char_or_comment(value, '\0');
+                if (*end == ';')
+                    *end = '\0';
+                rstrip(value);
+
+                /* Valid name[=:]value pair found, call handler */
+                strncpy0(prev_name, name, sizeof(prev_name));
+                if (!handler(user, section, name, value) && !error)
+                    error = lineno;
+            }
+            else if (!error) {
+                /* No '=' or ':' found on name[=:]value line */
+                error = lineno;
+            }
+        }
+
+        if (error)
+            break;
+    }
+
+    return error;
+}
+
+/* See documentation in header file. */
+int ini_parse(const char* filename,
+              int (*handler)(void*, const char*, const char*, const char*),
+              void* user)
+{
+    FILE* file;
+    int error;
+
+    file = fopen(filename, "r");
+    if (!file)
+        return -1;
+    error = ini_parse_file(file, handler, user);
+    fclose(file);
+    return error;
+}

parser.h

@@ -0,0 +1,34 @@
+/* 
+ * .INI file parser
+ */
+
+#include <stdio.h>
+
+/* Parse given INI-style file. May have [section]s, name=value pairs
+   (whitespace stripped), and comments starting with ';' (semicolon). Section
+   is "" if name=value pair parsed before any section heading. name:value
+   pairs are also supported as a concession to Python's ConfigParser.
+
+   For each name=value pair parsed, call handler function with given user
+   pointer as well as section, name, and value (data only valid for duration
+   of handler call). Handler should return nonzero on success, zero on error.
+
+   Returns 0 on success, line number of first error on parse error (doesn't
+   stop on first error), -1 on file open erro. 
+*/
+int ini_parse(const char* filename,
+              int (*handler)(void* user, const char* section,
+                             const char* name, const char* value),
+              void* user);
+
+/* Same as ini_parse(), but takes a FILE* instead of filename. This doesn't
+   close the file when it's finished -- the caller must do that. */
+int ini_parse_file(FILE* file,
+                   int (*handler)(void* user, const char* section,
+                                  const char* name, const char* value),
+                   void* user);
+
+/* Maximum line length for any line in INI file. */
+#ifndef INI_MAX_LINE
+#define INI_MAX_LINE 200
+#endif