From 03f2e59365a51b280c63549965d0c30766dddad9 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Mon, 21 Dec 2015 15:57:40 +0100 Subject: add clearenv MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- include/stdlib.h | 43 ++++++++++++++++++++++++++++++++++++++ src/stdlib/clearenv.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 101 insertions(+) create mode 100644 src/stdlib/clearenv.c diff --git a/include/stdlib.h b/include/stdlib.h index 3229384..ebfb5e2 100644 --- a/include/stdlib.h +++ b/include/stdlib.h @@ -288,6 +288,49 @@ long long int atoq(const char*) #endif +#if !defined(__PORTABLE) +/** + * This function is identical to `atoll`. + * + * This is a Linux libc extension. + * + * @since Always. + */ +long long int atoq(const char*) + __deprecated("'atoq' is obsolete and not portable, use 'atoll' instead.") + __GCC_ONLY(__attribute__((__warn_unused_result__, __nonnull__))); +#endif + + +#if defined(__SVID_SOURCE) || defined(__BSD_SOURCE) +/** + * This function shall in some manner clear the environment. + * + * To minimise the risk of fatal race conditions, this + * implementation will set the first element in + * `extern char** environ` to `NULL`, unless `environ` + * itself is `NULL`. This also reduces that risk that + * programs stop working when switching to slibc. + * + * The exact behaviour of this function depeneds of the + * implementations. Depending on the implementation, + * this may or may not entail setting `environ` to `NULL`. + * + * This function is a very common non-standard extension. + * + * @etymology (Clear) the (env)ironment! + * + * @returns This function is always successful, and will + * always return zero. However, according to the + * specifications, it shall return -1 on failure. + * + * @since Always. + */ +int clearenv(void) + __warning("It may be better to use `if (environ) *environ = NULL;`."); +#endif + + /* TODO implement rand-functions */ #define RAND_MAX 1 diff --git a/src/stdlib/clearenv.c b/src/stdlib/clearenv.c new file mode 100644 index 0000000..e393c01 --- /dev/null +++ b/src/stdlib/clearenv.c @@ -0,0 +1,58 @@ +/** + * slibc — Yet another C library + * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ +#include + + + +/** + * The process's environment variables. + */ +extern char** environ; + + + +/** + * This function shall in some manner clear the environment. + * + * To minimise the risk of fatal race conditions, this + * implementation will set the first element in + * `extern char** environ` to `NULL`, unless `environ` + * itself is `NULL`. This also reduces that risk that + * programs stop working when switching to slibc. + * + * The exact behaviour of this function depeneds of the + * implementations. Depending on the implementation, + * this may or may not entail setting `environ` to `NULL`. + * + * This function is a very common non-standard extension. + * + * @etymology (Clear) the (env)ironment! + * + * @returns This function is always successful, and will + * always return zero. However, according to the + * specifications, it shall return -1 on failure. + * + * @since Always. + */ +int clearenv(void) +{ + if (environ != NULL) + *environ = NULL; + return 0; +} + -- cgit v1.2.3-70-g09d2