cmd_nvedit.c: Add env exists command
env exists is a way to test (in hush) if an environment variable
exists. A workaround existed using printenv but this new command
doesn't require all the stdout/stderr redirection to prevent
printing information to the screen.
Example:
$ set testexists 1
$ env exists testexists && echo "yes"
yes
$ env exists testexists || echo "no"
$ set testexists
$ env exists testexists && echo "yes"
$ env exists testexists || echo "no"
no
$
Signed-off-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>
diff --git a/README b/README
index 91c3ac0..a4a450e 100644
--- a/README
+++ b/README
@@ -848,6 +848,7 @@
CONFIG_CMD_ELF * bootelf, bootvx
CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
CONFIG_CMD_ENV_FLAGS * display details about env flags
+ CONFIG_CMD_ENV_EXISTS * check existence of env variable
CONFIG_CMD_EXPORTENV * export the environment
CONFIG_CMD_EXT2 * ext2 command support
CONFIG_CMD_EXT4 * ext4 command support