Initial commit of block device interface and emulated block device

emubd/lfs_cfg.h

@@ -0,0 +1,74 @@
+/*
+ * Simple config parser
+ *
+ * Copyright (c) 2017 Christopher Haster
+ * Distributed under the MIT license
+ */
+#ifndef LFS_CFG_H
+#define LFS_CFG_H
+
+#include <stddef.h>
+#include <stdbool.h>
+#include <unistd.h>
+
+// This is a simple parser for config files
+//
+// The cfg file format is dumb simple. Attributes are
+// key value pairs separated by a single colon. Delimited
+// by comments (#) and newlines (\r\n) and trims
+// whitespace ( \t\v\f)
+//
+// Here's an example file
+// # Here is a dump example
+// looky: it's_an_attribute
+// hey_look: another_attribute
+//
+// huh: yeah_that's_basically_it # basically it
+
+// Internal config structure
+typedef struct lfs_cfg {
+    size_t len;
+    size_t size;
+
+    size_t blen;
+    size_t bsize;
+    char *buf;
+
+    struct lfs_cfg_attr {
+        unsigned key;
+        unsigned val;
+    } *attrs;
+} lfs_cfg_t;
+
+
+
+// Creates a cfg object and reads in the cfg file from the filename
+//
+// If the lfs_cfg_read fails, returns a negative value from the underlying
+// stdio functions
+int lfs_cfg_create(lfs_cfg_t *cfg, const char *filename);
+
+// Destroys the cfg object and frees any used memory
+void lfs_cfg_destroy(lfs_cfg_t *cfg);
+
+// Checks if a cfg attribute exists
+bool lfs_cfg_has(lfs_cfg_t *cfg, const char *key);
+
+// Retrieves a cfg attribute as a null-terminated string
+//
+// If the attribute does not exist, returns the string passed as def
+const char *lfs_cfg_get(lfs_cfg_t *cfg, const char *key, const char *def);
+
+// Retrieves a cfg attribute parsed as an int
+//
+// If the attribute does not exist or can't be parsed, returns the
+// integer passed as def
+ssize_t lfs_cfg_geti(lfs_cfg_t *cfg, const char *name, ssize_t def);
+
+// Retrieves a cfg attribute parsed as an unsigned int
+//
+// If the attribute does not exist or can't be parsed, returns the
+// integer passed as def
+size_t lfs_cfg_getu(lfs_cfg_t *cfg, const char *name, size_t def);
+
+#endif