Deprecate get_env.h and move content to env.{h,c} (#340)

* Deprecate get_env.h and move content to env.{h,c}

* Update documentation
* Merge test_get_env.cpp into test_env.cpp
* Use push/pop for Windows warning
* Remove rcutils/get_env.h includes
* Fix rcutils_get_home_dir doc

Signed-off-by: Christophe Bedard <[email protected]>

CMakeLists.txt

@@ -56,7 +56,6 @@ set(rcutils_sources
   src/filesystem.c
   src/find.c
   src/format_string.c
-  src/get_env.c
   src/hash_map.c
   src/logging.c
   src/process.c
@@ -311,19 +310,12 @@ if(BUILD_TESTING)
     target_link_libraries(test_string_array ${PROJECT_NAME})
   endif()
 
-  rcutils_custom_add_gtest(test_get_env test/test_get_env.cpp
+  rcutils_custom_add_gtest(test_env test/test_env.cpp
     ENV
       EMPTY_TEST=
       NORMAL_TEST=foo
     APPEND_LIBRARY_DIRS "$<TARGET_FILE_DIR:${PROJECT_NAME}>"
   )
-  if(TARGET test_get_env)
-    target_link_libraries(test_get_env ${PROJECT_NAME})
-  endif()
-
-  rcutils_custom_add_gtest(test_env test/test_env.cpp
-    APPEND_LIBRARY_DIRS "$<TARGET_FILE_DIR:${PROJECT_NAME}>"
-  )
   if(TARGET test_env)
     target_link_libraries(test_env ${PROJECT_NAME})
   endif()

include/rcutils/env.h

@@ -27,9 +27,6 @@ extern "C"
 #include "rcutils/macros.h"
 #include "rcutils/visibility_control.h"
 
-// TODO(cottsay): Deprecate get_env.h and eventually merge it here
-#include "rcutils/get_env.h"
-
 /// Set or un-set a process-scoped environment variable.
 /**
  * This function modifies the environment variables for the current process by
@@ -58,6 +55,66 @@ RCUTILS_WARN_UNUSED
 bool
 rcutils_set_env(const char * env_name, const char * env_value);
 
+/// Retrieve the value of the given environment variable if it exists, or "".
+/** The c-string which is returned in the env_value output parameter is only
+ * valid until the next time this function is called, because it is a direct
+ * pointer to the static storage.
+ * The variable env_value populated by this function should never have free()
+ * called on it.
+ * If the environment variable is not set, an empty string will be returned.
+ *
+ * In both cases, environment variable set or unset, NULL is returned unless
+ * an exception has occurred, in which case the error string is returned.
+ * For example:
+ *
+ * ```c
+ * #include <stdio.h>
+ * #include <rcutils/env.h>
+ * const char * env_value;
+ * const char * error_str;
+ * error_str = rcutils_get_env("SOME_ENV_VAR", &env_value);
+ * if (error_str != NULL) {
+ *   fprintf(stderr, "Error getting env var: %s\n", error_str);
+ * }
+ * printf("Valued of 'SOME_ENV_VAR': %s\n", env_value);
+ * ```
+ *
+ * This function cannot be concurrently called together with rcutils_set_env (or any platform specific equivalent)
+ * on different threads, but multiple concurrent calls to this function are thread safe.
+ *
+ * \param[in] env_name the name of the environment variable
+ * \param[out] env_value pointer to the value cstring, or "" if unset
+ * \return NULL on success (success can be returning an empty string), or
+ * \return an error string on failure.
+ */
+RCUTILS_PUBLIC
+RCUTILS_WARN_UNUSED
+const char *
+rcutils_get_env(const char * env_name, const char ** env_value);
+
+/// Retrieve the full path to the home directory.
+/**
+ * The c-string which is returned is only valid until the next time this
+ * function is called, because it is a direct pointer to the static storage.
+ * Also note that the string returned here should *not* be freed.
+ *
+ * The function first tries to get the HOME environment variable.
+ * If that variable exists and is non-empty, that will be returned.
+ * Otherwise, on Windows, the function tries to get the USERPROFILE environment variable.
+ * If that variable exists and is non-empty, that will be returned.
+ * Otherwise, NULL will be returned.
+ *
+ * This function cannot be thread-safely called together with rcutils_set_env
+ * (or any platform specific equivalent), but multiple calls to this function are thread safe.
+ *
+ * \return The home directory on success, or
+ * \return `NULL` on failure.
+ */
+RCUTILS_PUBLIC
+RCUTILS_WARN_UNUSED
+const char *
+rcutils_get_home_dir(void);
+
 #ifdef __cplusplus
 }
 #endif

include/rcutils/get_env.h

@@ -17,77 +17,14 @@
 #ifndef RCUTILS__GET_ENV_H_
 #define RCUTILS__GET_ENV_H_
 
-#ifdef __cplusplus
-extern "C"
-{
-#endif
-
-#include "rcutils/macros.h"
-#include "rcutils/visibility_control.h"
-
-/// Retrieve the value of the given environment variable if it exists, or "".
-/** The c-string which is returned in the env_value output parameter is only
- * valid until the next time this function is called, because it is a direct
- * pointer to the static storage.
- * The variable env_value populated by this function should never have free()
- * called on it.
- * If the environment variable is not set, an empty string will be returned.
- *
- * In both cases, environment variable set or unset, NULL is returned unless
- * an exception has occurred, in which case the error string is returned.
- * For example:
- *
- * ```c
- * #include <stdio.h>
- * #include <rcutils/get_env.h>
- * const char * env_value;
- * const char * error_str;
- * error_str = rcutils_get_env("SOME_ENV_VAR", &env_value);
- * if (error_str != NULL) {
- *   fprintf(stderr, "Error getting env var: %s\n", error_str);
- * }
- * printf("Valued of 'SOME_ENV_VAR': %s\n", env_value);
- * ```
- *
- * This function cannot be concurrently called together with rcutils_set_env (or any platform specific equivalent)
- * on different threads, but multiple concurrent calls to this function are thread safe.
- *
- * \param[in] env_name the name of the environment variable
- * \param[out] env_value pointer to the value cstring, or "" if unset
- * \return NULL on success (success can be returning an empty string), or
- * \return an error string on failure.
- */
-RCUTILS_PUBLIC
-RCUTILS_WARN_UNUSED
-const char *
-rcutils_get_env(const char * env_name, const char ** env_value);
+// TODO(christophebedard) remove this header completely in I-turtle
 
-/// Retrieve the full path to the home directory.
-/**
- * The c-string which is returned is only valid until the next time this
- * function is called, because it is a direct pointer to the static storage.
- * Also note that the string returned here should *not* be freed.
- *
- * The function first tries to get the HOME environment variable.
- * If that variable exists and is non-empty, that will be returned.
- * Otherwise, the function tries to get the USERPROFILE environment variable.
- * If that variable exists and is non-empty, that will be returned.
- * If neither exists, NULL will be returned.
- * The above algorithm is portable across both Unix and Windows.
- *
- * This function cannot be thread-safely called together with rcutils_set_env
- * (or any platform specific equivalent), but multiple calls to this function are thread safe.
- *
- * \return The home directory on success, or
- * \return `NULL` on failure.
- */
-RCUTILS_PUBLIC
-RCUTILS_WARN_UNUSED
-const char *
-rcutils_get_home_dir(void);
-
-#ifdef __cplusplus
-}
+#ifdef _MSC_VER
+#pragma message ("rcutils/get_env.h has been deprecated, please include rcutils/env.h instead")
+#else
+#warning rcutils/get_env.h has been deprecated, please include rcutils/env.h instead
 #endif
 
+#include "rcutils/env.h"
+
 #endif  // RCUTILS__GET_ENV_H_

src/env.c

@@ -18,13 +18,12 @@ extern "C"
 #endif
 
 #include <errno.h>
+#include <stdio.h>
 #include <stdlib.h>
 
 #include "rcutils/env.h"
 #include "rcutils/error_handling.h"
 
-// TODO(cottsay): Move the stuff in get_env.c in here
-
 bool
 rcutils_set_env(const char * env_name, const char * env_value)
 {
@@ -58,6 +57,58 @@ rcutils_set_env(const char * env_name, const char * env_value)
   return true;
 }
 
+#ifdef _WIN32
+#pragma warning(push)
+#pragma warning(disable : 4996)
+#endif
+
+const char *
+rcutils_get_env(const char * env_name, const char ** env_value)
+{
+  RCUTILS_CAN_RETURN_WITH_ERROR_OF("some string error");
+
+  if (NULL == env_name) {
+    return "argument env_name is null";
+  }
+  if (NULL == env_value) {
+    return "argument env_value is null";
+  }
+
+  // TODO(Suyash458): getenv is deprecated on Windows; consider using getenv_s instead
+  *env_value = getenv(env_name);
+
+  if (NULL == *env_value) {
+    *env_value = "";
+  }
+  return NULL;
+}
+
+#ifdef _WIN32
+#pragma warning(pop)
+#endif
+
+const char *
+rcutils_get_home_dir(void)
+{
+  const char * homedir;
+
+  if (rcutils_get_env("HOME", &homedir) == NULL && *homedir != '\0') {
+    // The HOME environment variable was set and is non-empty, return it.
+    return homedir;
+  }
+
+#ifdef _WIN32
+  // We didn't find a HOME variable, try USERPROFILE on Windows.
+  if (rcutils_get_env("USERPROFILE", &homedir) == NULL && *homedir != '\0') {
+    // The USERPROFILE environment variable was set and is non-empty, return it.
+    return homedir;
+  }
+#endif
+
+  // Couldn't get the home directory, return NULL.
+  return NULL;
+}
+
 #ifdef __cplusplus
 }
 #endif

src/filesystem.c

@@ -42,9 +42,9 @@ extern "C"
 #include <direct.h>
 #endif  // _WIN32
 
+#include "rcutils/env.h"
 #include "rcutils/error_handling.h"
 #include "rcutils/format_string.h"
-#include "rcutils/get_env.h"
 #include "rcutils/repl_str.h"
 #include "rcutils/strdup.h"
 

src/logging.c

@@ -43,10 +43,10 @@ extern "C"
 #endif
 
 #include "rcutils/allocator.h"
+#include "rcutils/env.h"
 #include "rcutils/error_handling.h"
 #include "rcutils/find.h"
 #include "rcutils/format_string.h"
-#include "rcutils/get_env.h"
 #include "rcutils/logging.h"
 #include "rcutils/snprintf.h"
 #include "rcutils/strdup.h"