Improve logging docs

include/zenoh_commons.h

@@ -4684,12 +4684,13 @@ z_result_t zc_config_to_string(const struct z_loaned_config_t *config,
  * Initializes the zenoh runtime logger, using rust environment settings or the provided fallback level.
  * E.g.: `RUST_LOG=info` will enable logging at info level. Similarly, you can set the variable to `error` or `debug`.
  *
- * Note that if the environment variable is not set, then fallback level will be used instead.
+ * Note that if the environment variable is not set, then fallback filter will be used instead.
+ * See https://docs.rs/env_logger/latest/env_logger/index.html for accepted filter format.
  *
- * @param level: The fallback level for logging if the environment variable is not set.
+ * @param level: The fallback filter if the `RUST_LOG` environment variable is not set. The format
  */
 ZENOHC_API
-z_result_t zc_init_log_from_env_or(const char *level);
+z_result_t zc_init_log_from_env_or(const char *fallback);
 /**
  * Initializes the zenoh runtime logger with custom callback.
  *
@@ -4990,6 +4991,7 @@ void zc_stop_z_runtime(void);
  * E.g.: `RUST_LOG=info` will enable logging at info level. Similarly, you can set the variable to `error` or `debug`.
  *
  * Note that if the environment variable is not set, then logging will not be enabled.
+ * See https://docs.rs/env_logger/latest/env_logger/index.html for accepted filter format.
  */
 ZENOHC_API
 void zc_try_init_log_from_env(void);

src/lib.rs

@@ -81,6 +81,7 @@ pub mod shm;
 /// E.g.: `RUST_LOG=info` will enable logging at info level. Similarly, you can set the variable to `error` or `debug`.
 ///
 /// Note that if the environment variable is not set, then logging will not be enabled.
+/// See https://docs.rs/env_logger/latest/env_logger/index.html for accepted filter format.
 #[no_mangle]
 pub extern "C" fn zc_try_init_log_from_env() {
     zenoh::try_init_log_from_env();
@@ -89,13 +90,16 @@ pub extern "C" fn zc_try_init_log_from_env() {
 /// Initializes the zenoh runtime logger, using rust environment settings or the provided fallback level.
 /// E.g.: `RUST_LOG=info` will enable logging at info level. Similarly, you can set the variable to `error` or `debug`.
 ///
-/// Note that if the environment variable is not set, then fallback level will be used instead.
+/// Note that if the environment variable is not set, then fallback filter will be used instead.
+/// See https://docs.rs/env_logger/latest/env_logger/index.html for accepted filter format.
 ///
-/// @param level: The fallback level for logging if the environment variable is not set.
+/// @param level: The fallback filter if the `RUST_LOG` environment variable is not set. The format
 #[no_mangle]
 #[allow(clippy::missing_safety_doc)]
-pub unsafe extern "C" fn zc_init_log_from_env_or(level: *const libc::c_char) -> result::z_result_t {
-    match std::ffi::CStr::from_ptr(level).to_str() {
+pub unsafe extern "C" fn zc_init_log_from_env_or(
+    fallback: *const libc::c_char,
+) -> result::z_result_t {
+    match std::ffi::CStr::from_ptr(fallback).to_str() {
         Ok(s) => {
             zenoh::init_log_from_env_or(s);
             result::Z_OK