From 88733e2c65b1b118e6e1a942d62a48ce62a5ea40 Mon Sep 17 00:00:00 2001 From: Andrew Ruder Date: Tue, 22 Oct 2013 19:07:34 -0500 Subject: [PATCH] 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 --- README | 1 + common/cmd_nvedit.c | 23 +++++++++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/README b/README index 91c3ac0fa7..a4a450efee 100644 --- a/README +++ b/README @@ -848,6 +848,7 @@ The following options need to be configured: 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 diff --git a/common/cmd_nvedit.c b/common/cmd_nvedit.c index ba9ba16972..0d4d02cfe0 100644 --- a/common/cmd_nvedit.c +++ b/common/cmd_nvedit.c @@ -1059,6 +1059,23 @@ sep_err: } #endif +#if defined(CONFIG_CMD_ENV_EXISTS) +static int do_env_exists(cmd_tbl_t *cmdtp, int flag, int argc, + char * const argv[]) +{ + ENTRY e, *ep; + + if (argc < 2) + return CMD_RET_USAGE; + + e.key = argv[1]; + e.data = NULL; + hsearch_r(e, FIND, &ep, &env_htab, 0); + + return (ep == NULL) ? 1 : 0; +} +#endif + /* * New command line interface: "env" command with subcommands */ @@ -1094,6 +1111,9 @@ static cmd_tbl_t cmd_env_sub[] = { U_BOOT_CMD_MKENT(save, 1, 0, do_env_save, "", ""), #endif U_BOOT_CMD_MKENT(set, CONFIG_SYS_MAXARGS, 0, do_env_set, "", ""), +#if defined(CONFIG_CMD_ENV_EXISTS) + U_BOOT_CMD_MKENT(exists, 2, 0, do_env_exists, "", ""), +#endif }; #if defined(CONFIG_NEEDS_MANUAL_RELOC) @@ -1136,6 +1156,9 @@ static char env_help_text[] = #if defined(CONFIG_CMD_EDITENV) "env edit name - edit environment variable\n" #endif +#if defined(CONFIG_CMD_ENV_EXISTS) + "env exists name - tests for existence of variable\n" +#endif #if defined(CONFIG_CMD_EXPORTENV) "env export [-t | -b | -c] [-s size] addr [var ...] - export environment\n" #endif -- 2.39.5