README: U_BOOT_ENV_CALLBACK functions

Describe the interface of environment variable callback functions. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

README: U_BOOT_ENV_CALLBACK functions
Describe the interface of environment variable callback functions. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Heinrich Schuchardt · Tom Rini
1 parent 938b05a5d7
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README
@@ -3943,6 +3943,17 @@
 regular expression. This allows multiple variables to be connected to
 the same callback without explicitly listing them all out.
  
+The signature of the callback functions is:
+
+    int callback(const char *name, const char *value, enum env_op op, int flags)
+
+* name - changed environment variable
+* value - new value of the environment variable
+* op - operation (create, overwrite, or delete)
+* flags - attributes of the environment variable change, see flags H_* in
+  include/search.h
+
+The return value is 0 if the variable change is accepted and 1 otherwise.
  
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...	...	@@ -3943,6 +3943,17 @@
3943	3943	regular expression. This allows multiple variables to be connected to
3944	3944	the same callback without explicitly listing them all out.
3945	3945
	3946	+The signature of the callback functions is:
	3947	+
	3948	+ int callback(const char name, const char value, enum env_op op, int flags)
	3949	+
	3950	+* name - changed environment variable
	3951	+* value - new value of the environment variable
	3952	+* op - operation (create, overwrite, or delete)
	3953	+* flags - attributes of the environment variable change, see flags H_* in
	3954	+ include/search.h
	3955	+
	3956	+The return value is 0 if the variable change is accepted and 1 otherwise.
3946	3957
3947	3958	Command Line Parsing:
3948	3959	=====================