1 files changed, 211 insertions, 0 deletions
diff --git a/config_parser.c b/config_parser.c
new file mode 100644
index 0000000..0bd3e5b
--- /dev/null
+++ b/config_parser.c
@@ -0,0 +1,211 @@
+/*
+ *
+ * File		:	config_parser.c
+ *
+ * Author	:	Zurcher Jeremy
+ *
+ * Date		:
+ *
+ * Purpose	:
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "config_parser.h"
+
+#define COMMENT '#'
+#define STREND '\0'
+#define NEWLINE '\n'
+#define TABULATION '\t'
+#define SPACE ' '
+
+enum { NOPE, UNFINISHED_LINE, UNFINISHED_COMMENT };
+
+struct config_reader {
+    int fd;
+    int last;
+    char *pos;
+    char *end;
+    int state;
+    int current_line;
+    char buffer[BUFFLEN];
+};
+
+static struct config_reader reader = { 0 };
+
+#ifdef _DEBUG_
+static void debug_buffer() {
+    printf("\tBUFFER : ");
+    int i;
+    for (i=0; i<BUFFLEN; i++) {
+        char ch = reader.buffer[i];
+        if(ch==NEWLINE)printf("*");
+        else if(ch==STREND)printf("@");
+        else printf("%c",ch);
+    }
+    printf("\n\tpos : %c[%d]\n",*reader.pos,(reader.pos-reader.buffer));
+    printf("\tend : %c[%d]\n",*reader.end,(reader.end-reader.buffer));
+}
+#endif /* _DEBUG_ */
+
+static int feed_buffer(int fd, char *buffer, int len)
+{
+    int ret;
+    if(reader.last) return 0;
+    ret = read(fd,buffer,len);
+    if(ret==-1) return -1;
+    if(ret<len) reader.last = 1;
+    buffer[ret] = STREND;
+    reader.pos = buffer;
+    reader.end = &buffer[ret];
+    return ret;
+}
+
+static char* eat_comment(char *from)
+{
+    int ret;
+    char *tmp;
+    for(;;) {
+        tmp = strchr(from, NEWLINE);
+        if(tmp!=NULL) {
+            reader.current_line++;
+            return tmp;
+        }
+        ret = feed_buffer(reader.fd, reader.buffer, BUFFLEN-1);
+        if(ret==-1) return (char*)-1;
+        if(ret==0) return NULL;
+        from = reader.pos;
+    }
+}
+
+static char* clean_tail(char *str)
+{
+    char *tmp = strchr(str, COMMENT);
+    if(tmp!=NULL) {
+        *tmp=STREND;
+        reader.state = UNFINISHED_COMMENT;
+    } else {
+        reader.state = UNFINISHED_LINE;
+    }
+    tmp = strchr(str, STREND);
+    for(;;) {
+        tmp--;
+        if(*tmp!=SPACE && *tmp!=TABULATION) break;
+    }
+    tmp++;
+    *tmp=STREND;
+    return tmp;
+}
+
+static char* prepare_line()
+{
+    int len;
+    int ret;
+    char *cret;
+    char *tmp;
+    tmp = strchr(reader.pos, NEWLINE);
+    if(tmp!=NULL) {
+        *tmp=STREND;
+        cret = reader.pos;
+        reader.pos = tmp+1;
+        clean_tail(cret);
+        reader.state = NOPE;
+        return cret;
+    }
+    len = (reader.end-reader.pos);
+    memmove(reader.buffer,reader.pos,len);
+    reader.pos = reader.buffer+len;
+    ret = feed_buffer(reader.fd, reader.pos, reader.end-reader.pos);
+    if(ret==-1) return (char*)-1;
+    tmp = strchr(reader.pos, NEWLINE);
+    if(tmp!=NULL) {
+        *tmp=STREND;
+        reader.pos = tmp+1;
+        clean_tail(reader.buffer);
+        reader.state = NOPE;
+    }
+    else {
+        clean_tail(reader.pos);
+    }
+    return reader.buffer;
+}
+
+static char* find_next_token()
+{
+    int ret;
+    char *end;
+    char *tmp = reader.pos;
+    if(reader.state==UNFINISHED_COMMENT){
+        tmp=eat_comment(reader.pos);
+        if(tmp==(char*)-1) return (char*)-1;
+        if(tmp==NULL) return NULL;
+        reader.state=NOPE;
+    }
+    else if (reader.state==UNFINISHED_LINE) {
+        ret = feed_buffer(reader.fd, reader.buffer, BUFFLEN-1);
+        if(ret==-1) return (char*)-1;
+        if(ret==0) return NULL;
+        reader.state=NOPE;
+        return prepare_line();
+    }
+    end = reader.end;
+    reader.current_line++;
+    for(;;) {
+        if(tmp==end) {
+            int ret = feed_buffer(reader.fd, reader.buffer, BUFFLEN-1);
+            if(ret==-1) return (char*)-1;
+            if(ret==0) return NULL;
+            tmp = reader.pos;
+            end = reader.end;
+        }
+        if(*tmp==NEWLINE) {
+            reader.current_line++;
+        }
+        else if(*tmp==COMMENT) {
+            tmp = eat_comment(tmp);
+            if(tmp==(char*)-1) return (char*)-1;
+            if(tmp==NULL) return NULL;
+            end = reader.end;
+        }
+        else if(*tmp!=SPACE || *tmp!=TABULATION) {
+            reader.pos = tmp;
+            return prepare_line();
+        }
+        tmp++;
+    }
+}
+
+static int init(char *filename)
+{
+    if(reader.fd) close(reader.fd);
+    reader.fd = open(filename,O_RDONLY);
+    if(reader.fd==-1) return 1;
+    reader.state = NOPE;
+    reader.last = 0;
+    reader.current_line = 0;
+    reader.pos = reader.end = reader.buffer;
+    return 0;
+}
+
+int read_config(char *filename, config_callback callback)
+{
+    int ret = EXIT_SUCCESS;
+    char *token;
+    if(init(filename)) return EXIT_FAILURE;
+    for(;;) {
+        token = find_next_token();
+        if(token==NULL) break;
+        if(token==(char*)-1) { ret=EXIT_FAILURE; break; }
+        ret = callback(token,reader.state!=NOPE);
+        if(ret) break;
+    }
+    close(reader.fd);
+    reader.fd = -1;
+    return ret;
+}