diff options
Diffstat (limited to 'src/libutil/environment-variables.cc')
-rw-r--r-- | src/libutil/environment-variables.cc | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/src/libutil/environment-variables.cc b/src/libutil/environment-variables.cc new file mode 100644 index 000000000..71c404a0e --- /dev/null +++ b/src/libutil/environment-variables.cc @@ -0,0 +1,51 @@ +#include <cstring> +#include <map> +#include <optional> +#include <string> + +extern char * * environ __attribute__((weak)); + +namespace nix { + +std::optional<std::string> getEnv(const std::string & key) +{ + char * value = getenv(key.c_str()); + if (!value) return {}; + return std::string(value); +} + +std::optional<std::string> getEnvNonEmpty(const std::string & key) { + auto value = getEnv(key); + if (value == "") return {}; + return value; +} + +std::map<std::string, std::string> getEnv() +{ + std::map<std::string, std::string> env; + for (size_t i = 0; environ[i]; ++i) { + auto s = environ[i]; + auto eq = strchr(s, '='); + if (!eq) + // invalid env, just keep going + continue; + env.emplace(std::string(s, eq), std::string(eq + 1)); + } + return env; +} + + +void clearEnv() +{ + for (auto & name : getEnv()) + unsetenv(name.first.c_str()); +} + +void replaceEnv(const std::map<std::string, std::string> & newEnv) +{ + clearEnv(); + for (auto & newEnvVar : newEnv) + setenv(newEnvVar.first.c_str(), newEnvVar.second.c_str(), 1); +} + +} |