Initial commit

src/common/path.c

@@ -0,0 +1,169 @@
+
+/*
+ * Copyright (C) 2010  Archived
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU 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 General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * the design goal here is to not use buffers because 
+ * path's can be extremely long (slightly overexaggerated but extreme cases are extreme).
+ * so we use funky heap memory based algorithms instead :)
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "debug.h"
+#include "path.h"
+
+/*
+ * allocates and initilizes a path
+ */
+static char* alloc_path(size_t s) {
+	
+	char *ptr;
+		
+	if (s < 1)
+		return NULL;
+		
+	if ((ptr = malloc(s+1)) == NULL)
+		return NULL;
+		
+	*ptr = '/';
+	memset(ptr+1, 0, s);
+		
+	return ptr;
+}
+
+static const char* path_clear(const char *path) {
+	
+	while(*path == '/')
+		path++;
+	
+	return path;
+}
+
+static inline int has_delim(const char *str) {
+	
+	if (str == NULL)
+		return 0;
+	
+	return strchr(str, '/') != NULL;
+}
+
+/*
+ * copy a clean path to buf
+ * NOTE: buffer should be atleast of size pathlen(path)
+ */
+static char* cpy_path(char *buf, const char *path) {
+	
+	if(!*path)
+		return buf;
+	
+	while(*path) {
+		
+		*(buf++) = *path;
+		
+		if (*path == '/')
+			path = path_clear(path);
+		else
+			path++;
+	}
+
+	if (*(buf-1) != '/')
+		*(buf++) = '/';
+	
+	dassert(*buf == 0);
+	
+	return buf;
+}
+
+int abspath(const char *path) {
+	
+	if (*path != '/')
+		return 0;
+	
+	return strstr(path, "/./")  == NULL && 
+		   strstr(path, "/../") == NULL;
+}
+
+size_t pathlen(const char *path) {
+	
+	size_t size = 0;
+	
+	while(*path != 0) {
+		
+		size++;
+		
+		if (*path == '/')
+			path = path_clear(path);
+		else if (*(++path) == 0)
+			size++;
+	}
+	
+	return size;
+}
+
+char* fmt_path(const char *base, const char *name, unsigned char dir) {
+
+	char *ptr, *ret;
+	size_t size;
+	
+	if (base == NULL || !abspath(base) || has_delim(name))
+		return NULL;
+	
+	size = pathlen(base);
+	
+	if (name != NULL) {
+		size += strlen(name);
+		if (dir) size++;
+	}
+	
+	if((ptr = alloc_path(size)) == NULL)
+		return NULL;
+	
+	ret = ptr;
+	
+	ptr = cpy_path(ptr, base);
+	
+	dassert((ptr-ret) == pathlen(base));
+	
+	if (name != NULL) {
+		memcpy(ptr, name, strlen(name));
+		if (dir) *(ptr+strlen(name)) = '/';
+	}
+	
+	return ret;
+}
+
+char* split_path(const char *path) {
+	return NULL;
+}
+
+const char* basename(const char *path) {
+	
+	const char *last = path+strlen(path);
+
+	if (*last == '/')
+		last--;
+	
+	while(path != last) {
+		if(*last == '/')
+			break;
+		last--;
+	}
+	
+	return last;
+}