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docs: Fix broken URLs & permanent redirects

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Angus Gratton
2020-03-23 10:27:51 +11:00
committed by Angus Gratton
parent a6b522c0f4
commit 52d888a68b
38 changed files with 81 additions and 77 deletions
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docs/en/api-guides/error-handling.rst
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@@ -39,7 +39,7 @@ Converting error codes to error messages
For each error code defined in ESP-IDF components, :cpp:type:`esp_err_t` value can be converted to an error code name using :cpp:func:`esp_err_to_name` or :cpp:func:`esp_err_to_name_r` functions. For example, passing ``0x101`` to :cpp:func:`esp_err_to_name` will return "ESP_ERR_NO_MEM" string. Such strings can be used in log output to make it easier to understand which error has happened.
Additionally, :cpp:func:`esp_err_to_name_r` function will attempt to interpret the error code as a `standard POSIX error code <http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/errno.h.html>`_, if no matching ``ESP_ERR_`` value is found. This is done using ``strerror_r`` function. POSIX error codes (such as ``ENOENT``, ``ENOMEM``) are defined in ``errno.h`` and are typically obtained from ``errno`` variable. In ESP-IDF this variable is thread-local: multiple FreeRTOS tasks have their own copies of ``errno``. Functions which set ``errno`` only modify its value for the task they run in.
Additionally, :cpp:func:`esp_err_to_name_r` function will attempt to interpret the error code as a `standard POSIX error code <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/errno.h.html>`_, if no matching ``ESP_ERR_`` value is found. This is done using ``strerror_r`` function. POSIX error codes (such as ``ENOENT``, ``ENOMEM``) are defined in ``errno.h`` and are typically obtained from ``errno`` variable. In ESP-IDF this variable is thread-local: multiple FreeRTOS tasks have their own copies of ``errno``. Functions which set ``errno`` only modify its value for the task they run in.
This feature is enabled by default, but can be disabled to reduce application binary size. See :ref:`CONFIG_ESP_ERR_TO_NAME_LOOKUP`. When this feature is disabled, :cpp:func:`esp_err_to_name` and :cpp:func:`esp_err_to_name_r` are still defined and can be called. In this case, :cpp:func:`esp_err_to_name` will return ``UNKNOWN ERROR``, and :cpp:func:`esp_err_to_name_r` will return ``Unknown error 0xXXXX(YYYYY)``, where ``0xXXXX`` and ``YYYYY`` are the hexadecimal and decimal representations of the error code, respectively.