[U-Boot] [PATCH] env: Provide programmatic equivalent to 'setenv -f'

[James Byrne]

Add env_force() to provide an equivalent to 'setenv -f' that can be used
programmatically.

Also tighten up the definition of argv in _do_env_set() so that
'const char *' pointers are used.

Signed-off-by: James Byrne <james.byrne at origamienergy.com>

---

 cmd/nvedit.c  | 43 +++++++++++++++++++++++++++++--------------
 include/env.h | 13 +++++++++++++
 2 files changed, 42 insertions(+), 14 deletions(-)

diff --git a/cmd/nvedit.c b/cmd/nvedit.c
index 99a3bc57b1..1f363ba9f4 100644
--- a/cmd/nvedit.c
+++ b/cmd/nvedit.c
@@ -221,10 +221,12 @@ DONE:
  * Set a new environment variable,
  * or replace or delete an existing one.
  */
-static int _do_env_set(int flag, int argc, char * const argv[], int env_flag)
+static int _do_env_set(int flag, int argc, const char * const argv[],
+		       int env_flag)
 {
 	int   i, len;
-	char  *name, *value, *s;
+	const char *name;
+	char *value, *s;
 	struct env_entry e, *ep;
 
 	debug("Initial value for argc=%d\n", argc);
@@ -235,7 +237,7 @@ static int _do_env_set(int flag, int argc, char * const argv[], int env_flag)
 #endif
 
 	while (argc > 1 && **(argv + 1) == '-') {
-		char *arg = *++argv;
+		const char *arg = *++argv;
 
 		--argc;
 		while (*++arg) {
@@ -277,7 +279,7 @@ static int _do_env_set(int flag, int argc, char * const argv[], int env_flag)
 		return 1;
 	}
 	for (i = 2, s = value; i < argc; ++i) {
-		char *v = argv[i];
+		const char *v = argv[i];
 
 		while ((*s++ = *v++) != '\0')
 			;
@@ -299,18 +301,30 @@ static int _do_env_set(int flag, int argc, char * const argv[], int env_flag)
 	return 0;
 }
 
-int env_set(const char *varname, const char *varvalue)
+static int do_programmatic_env_set(int argc, const char * const argv[])
 {
-	const char * const argv[4] = { "setenv", varname, varvalue, NULL };
-
 	/* before import into hashtable */
 	if (!(gd->flags & GD_FLG_ENV_READY))
 		return 1;
 
-	if (varvalue == NULL || varvalue[0] == '\0')
-		return _do_env_set(0, 2, (char * const *)argv, H_PROGRAMMATIC);
-	else
-		return _do_env_set(0, 3, (char * const *)argv, H_PROGRAMMATIC);
+	if (!argv[argc - 1] || argv[argc - 1][0] == '\0')
+		argc--;
+
+	return _do_env_set(0, argc, argv, H_PROGRAMMATIC);
+}
+
+int env_set(const char *varname, const char *varvalue)
+{
+	const char * const argv[4] = {"setenv", varname, varvalue, NULL};
+
+	return do_programmatic_env_set(3, argv);
+}
+
+int env_force(const char *varname, const char *varvalue)
+{
+	const char * const argv[5] = {"setenv", "-f", varname, varvalue, NULL};
+
+	return do_programmatic_env_set(4, argv);
 }
 
 /**
@@ -382,7 +396,8 @@ static int do_env_set(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	if (argc < 2)
 		return CMD_RET_USAGE;
 
-	return _do_env_set(flag, argc, argv, H_INTERACTIVE);
+	return _do_env_set(flag, argc, (const char * const *)argv,
+			   H_INTERACTIVE);
 }
 
 /*
@@ -643,12 +658,12 @@ static int do_env_edit(cmd_tbl_t *cmdtp, int flag, int argc,
 	if (buffer[0] == '\0') {
 		const char * const _argv[3] = { "setenv", argv[1], NULL };
 
-		return _do_env_set(0, 2, (char * const *)_argv, H_INTERACTIVE);
+		return _do_env_set(0, 2, _argv, H_INTERACTIVE);
 	} else {
 		const char * const _argv[4] = { "setenv", argv[1], buffer,
 			NULL };
 
-		return _do_env_set(0, 3, (char * const *)_argv, H_INTERACTIVE);
+		return _do_env_set(0, 3, _argv, H_INTERACTIVE);
 	}
 }
 #endif /* CONFIG_CMD_EDITENV */
diff --git a/include/env.h b/include/env.h
index b72239f6a5..37bbf1117d 100644
--- a/include/env.h
+++ b/include/env.h
@@ -145,6 +145,19 @@ int env_get_yesno(const char *var);
  */
 int env_set(const char *varname, const char *value);
 
+/**
+ * env_force() - forcibly set an environment variable
+ *
+ * This sets or deletes the value of an environment variable. It is the same
+ * as env_set(), except that the variable will be forcibly updated/deleted,
+ * even if it has access protection flags set.
+ *
+ * @varname: Variable to adjust
+ * @value: Value to set for the variable, or NULL or "" to delete the variable
+ * @return 0 if OK, 1 on error
+ */
+int env_force(const char *varname, const char *varvalue);
+
 /**
  * env_get_ulong() - Return an environment variable as an integer value
  *
-- 
2.24.0