From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kdGK5-000779-G7 for barebox@lists.infradead.org; Thu, 12 Nov 2020 17:23:50 +0000 From: Ahmad Fatoum Date: Thu, 12 Nov 2020 18:23:46 +0100 Message-Id: <20201112172347.385-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH 1/2] fs: introduce unsetenv() to prepare for changing setenv(var, "") behavior To: barebox@lists.infradead.org Cc: Ahmad Fatoum Currently, we treat setenv(var, "") and setenv(var, NULL) the same and delete var, which is surprising and leads to subtle quirks: - setenv(var, "") is specified by POSIX to set var to an empty string, but barebox uses it to delete variables - nv.user= calls nv_set with NULL parameter, but nv user="" doesn't Make the API more POSIX-like by providing unsetenv with the expected semantics. Most user code can then use unsetenv without worrying about whether "" or NULL is the magic deletion value. Signed-off-by: Ahmad Fatoum --- commands/readlink.c | 2 +- commands/setenv.c | 7 ++++++- fs/fs.c | 2 +- include/environment.h | 5 +++++ net/ifup.c | 2 +- 5 files changed, 14 insertions(+), 4 deletions(-) diff --git a/commands/readlink.c b/commands/readlink.c index fdcf175f56bb..81ad25c733ab 100644 --- a/commands/readlink.c +++ b/commands/readlink.c @@ -50,7 +50,7 @@ static int do_readlink(int argc, char *argv[]) return 0; err: - setenv(argv[optind + 1], ""); + unsetenv(argv[optind + 1]); return 1; } diff --git a/commands/setenv.c b/commands/setenv.c index ad2677065552..6992f604f513 100644 --- a/commands/setenv.c +++ b/commands/setenv.c @@ -10,6 +10,7 @@ static int do_setenv(int argc, char *argv[]) { char *equal; + int ret; if (argc < 2) return COMMAND_ERROR_USAGE; @@ -21,8 +22,12 @@ static int do_setenv(int argc, char *argv[]) argv[2] = &equal[1]; } + if (argv[2]) + ret = setenv(argv[1], argv[2]); + else + ret = unsetenv(argv[1]); - return setenv(argv[1], argv[2]) ? COMMAND_ERROR : COMMAND_SUCCESS; + return ret ? COMMAND_ERROR : COMMAND_SUCCESS; } BAREBOX_CMD_HELP_START(setenv) diff --git a/fs/fs.c b/fs/fs.c index f41e4b9b72cd..00b8645fb0e9 100644 --- a/fs/fs.c +++ b/fs/fs.c @@ -3066,7 +3066,7 @@ static int automount_mount(struct dentry *dentry) setenv("automount_path", am->path); export("automount_path"); ret = run_command(am->cmd); - setenv("automount_path", NULL); + unsetenv("automount_path"); if (ret) { printf("running automount command '%s' failed\n", diff --git a/include/environment.h b/include/environment.h index 9488e4e1ac1f..19e522cfb6b4 100644 --- a/include/environment.h +++ b/include/environment.h @@ -87,6 +87,11 @@ int env_push_context(void); int export(const char *); +static inline int unsetenv(const char *var) +{ + return setenv(var, NULL); +} + #endif /* _ENVIRONMENT_H_ */ /** diff --git a/net/ifup.c b/net/ifup.c index a74037939b8a..1870f7401714 100644 --- a/net/ifup.c +++ b/net/ifup.c @@ -86,7 +86,7 @@ static int source_env_network(struct eth_device *edev) env_push_context(); for (i = 0; i < ARRAY_SIZE(vars); i++) - setenv(vars[i], ""); + unsetenv(vars[i]); cmd = basprintf("source /env/network/%s", edev->devname); ret = run_command(cmd); -- 2.28.0 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox