env: add env_update()

This add/append/replace the sub value of an environment variable.

Change-Id: I0fcda0a1c631013eb9458a04a09546ba1c643db3
Signed-off-by: Joseph Chen <chenjh@rock-chips.com>

cmd/nvedit.c

@@ -297,6 +297,222 @@ int env_set(const char *varname, const char *varvalue)
 		return _do_env_set(0, 3, (char * const *)argv, H_PROGRAMMATIC);
 }
 
+static int env_append(const char *varname, const char *varvalue)
+{
+	int len = 0;
+	char *oldvalue, *newvalue;
+
+	/* before import into hashtable */
+	if (!(gd->flags & GD_FLG_ENV_READY) || !varname)
+		return 1;
+
+	if (varvalue)
+		len += strlen(varvalue);
+
+	oldvalue = env_get(varname);
+	if (oldvalue) {
+		len += strlen(oldvalue);
+		/* Exist ! */
+		if (strstr(oldvalue, varvalue))
+			return 0;
+	}
+
+	newvalue = malloc(len + 2);
+	if (!newvalue) {
+		printf("Error: malloc in %s failed!\n", __func__);
+		return 1;
+	}
+
+	*newvalue = '\0';
+
+	if (oldvalue) {
+		strcpy(newvalue, oldvalue);
+		strcat(newvalue, " ");
+	}
+
+	if (varvalue)
+		strcat(newvalue, varvalue);
+
+	env_set(varname, newvalue);
+	free(newvalue);
+
+	return 0;
+}
+
+static int env_replace(const char *varname, const char *substr,
+		       const char *replacement)
+{
+	char *oldvalue, *newvalue, *dst, *sub;
+	int substr_len, replace_len, oldvalue_len, len;
+
+	/* before import into hashtable */
+	if (!(gd->flags & GD_FLG_ENV_READY) || !varname)
+		return 1;
+
+	oldvalue = env_get(varname);
+	if (!oldvalue)
+		return 1;
+
+	sub = strstr(oldvalue, substr);
+	if (!sub)
+		return 1;
+
+	oldvalue_len = strlen(oldvalue) + 1;
+	substr_len = strlen(substr);
+	replace_len = strlen(replacement);
+
+	if (replace_len >= substr_len)
+		len = oldvalue_len + replace_len - substr_len;
+	else
+		len = oldvalue_len + substr_len - replace_len;
+
+	newvalue = malloc(len);
+	if (!newvalue) {
+		printf("Error: malloc in %s failed!\n", __func__);
+		return 1;
+	}
+
+	*newvalue = '\0';
+
+	/*
+	 * Orignal string is splited like format: [str1.. substr str2..]
+	 */
+
+	/* str1.. */
+	dst = newvalue;
+	dst = strncat(dst, oldvalue, sub - oldvalue);
+
+	/* substr */
+	dst += sub - oldvalue;
+	dst = strncat(dst, replacement, replace_len);
+
+	/* str2.. */
+	dst += replace_len;
+	len = oldvalue_len - substr_len - (sub - oldvalue);
+	dst = strncat(dst, sub + substr_len, len);
+
+	env_set(varname, newvalue);
+	free(newvalue);
+
+	return 0;
+}
+
+#define ARGS_ITEM_NUM	50
+
+int env_update(const char *varname, char *varvalue)
+{
+	/* 'a_' means "varargs_'; 'v_' means 'varvalue_' */
+	char *varargs;
+	char *a_title, *v_title;
+	char *a_string_tok, *a_item_tok = NULL;
+	char *v_string_tok, *v_item_tok = NULL;
+	char *a_item, *a_items[ARGS_ITEM_NUM] = { NULL };
+	char *v_item, *v_items[ARGS_ITEM_NUM] = { NULL };
+	bool match = false;
+	int i = 0, j = 0;
+
+	/* Before import into hashtable */
+	if (!(gd->flags & GD_FLG_ENV_READY) || !varname)
+		return 1;
+
+	/* If varname doesn't exist, create it and set varvalue */
+	varargs = env_get(varname);
+	if (!varargs) {
+		env_set(varname, varvalue);
+		return 0;
+	}
+
+	/* Malloc a temporary varargs for strtok */
+	a_string_tok = strdup(varargs);
+	if (!a_string_tok) {
+		printf("Error: strdup in failed, line=%d\n", __LINE__);
+		return 1;
+	}
+
+	/* Malloc a temporary varvalue for strtok */
+	v_string_tok = strdup(varvalue);
+	if (!v_string_tok) {
+		free(a_string_tok);
+		printf("Error: strdup in failed, line=%d\n", __LINE__);
+		return 1;
+	}
+
+	/* Splite varargs into items containing "=" by the blank */
+	a_item = strtok(a_string_tok, " ");
+	while (a_item && i < ARGS_ITEM_NUM) {
+		debug("%s: [a_item %d]: %s\n", __func__, i, a_item);
+		if (strstr(a_item, "="))
+			a_items[i++] = a_item;
+		a_item = strtok(NULL, " ");
+	}
+
+	/*
+	 * Splite varvalue into items containing "=" by the blank.
+	 * parse varvalue title, eg: "bootmode=emmc", title is "bootmode"
+	 */
+	v_item = strtok(v_string_tok, " ");
+	while (v_item && j < ARGS_ITEM_NUM) {
+		debug("%s: <v_item %d>: %s\n", __func__, j, v_item);
+		if (strstr(v_item, "="))
+			v_items[j++] = v_item;
+		else
+			env_append(varname, v_item);
+		v_item = strtok(NULL, " ");
+	}
+
+	/* For every v_item, search its title */
+	for (j = 0; j < ARGS_ITEM_NUM && v_items[j]; j++) {
+		v_item = v_items[j];
+		/* Malloc a temporary a_item for strtok */
+		v_item_tok = strdup(v_item);
+		if (!v_item_tok) {
+			printf("Error: strdup in failed, line=%d\n", __LINE__);
+			free(a_string_tok);
+			free(v_string_tok);
+			return 1;
+		}
+		v_title = strtok(v_item_tok, "=");
+		debug("%s: <v_title>: %s\n", __func__, v_title);
+
+		/* For every a_item, search its title */
+		for (i = 0; i < ARGS_ITEM_NUM && a_items[i]; i++) {
+			a_item = a_items[i];
+			/* Malloc a temporary a_item for strtok */
+			a_item_tok = strdup(a_item);
+			if (!a_item_tok) {
+				printf("Error: strdup in failed, line=%d\n", __LINE__);
+				free(a_string_tok);
+				free(v_string_tok);
+				free(v_item_tok);
+				return 1;
+			}
+
+			a_title = strtok(a_item_tok, "=");
+			debug("%s: [a_title]: %s\n", __func__, a_title);
+			if (!strcmp(a_title, v_title)) {
+				/* Find! replace it */
+				env_replace(varname, a_item, v_item);
+				free(a_item_tok);
+				match = true;
+				break;
+			}
+			free(a_item_tok);
+		}
+
+		/* Not find, just append */
+		if (!match)
+			env_append(varname, v_item);
+
+		match = false;
+		free(v_item_tok);
+	}
+
+	free(v_string_tok);
+	free(a_string_tok);
+
+	return 0;
+}
+
 /**
  * Set an environment variable to an integer value
  *

include/common.h

@@ -378,6 +378,17 @@ int env_get_yesno(const char *var);
  */
 int env_set(const char *varname, const char *value);
 
+/**
+ * env_update() - update sub value of an environment variable
+ *
+ * This add/append/replace the sub value of an environment variable.
+ *
+ * @varname: Variable to adjust
+ * @valude: Value to append/replace
+ * @return 0 if OK, 1 on error
+ */
+int env_update(const char *varname, char *varvalue);
+
 /**
  * env_set_ulong() - set an environment variable to an integer
  *