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One thing that is not-so-subtly broken is re-entrancy (e.g. in functions like `strtok()`; fixed later with `strtok_s()` in C11: https://en.cppreference.com/w/c

One thing that is not-so-subtly broken is re-entrancy (e.g. in functions like `strtok()`; fixed later with `strtok_s()` in C11: https://en.cppreference.com/w/c/string/byte/strtok https://en.cppreference.com/w/c/string/byte/strtok About getenv: This sort-of fixed with `getenv_s()` in C11 https://en.cppreference.com/w/c/program/getenv https://en.cppreference.com/w/c/program/getenv

loeg 6y ago
Re: getenv_s: Annex K is (still) optional. Compliant C11+ implementations may not have getenv_s.
- josephcsible 6y ago
  This is an understatement. The only relevant platform that supports Annex K is MSVC, and this is unlikely to change any time soon.
  - loeg 6y ago
    And even MSVC does not actually implement the API specified in Annex K. Annex K was inspired by MSVC's design, but they diverged: > Microsoft Visual Studio implements an early version of the APIs. However, the implementation is incomplete and conforms neither to C11 nor to the original TR 24731-1. For example, it doesn't provide the set_constraint_handler_s function but instead defines a _invalid_parameter_handler _set_invalid_parameter_handler(_invalid_parameter_handler) function with similar behavior but a slightly different and incompatible signature. It also doesn't define the abort_handler_s and ignore_handler_s functions, the memset_s function (which isn't part of the TR), or the RSIZE_MAX macro.The Microsoft implementation also doesn't treat overlapping source and destination sequences as runtime-constraint violations and instead has undefined behavior in such cases. [0]: http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1967.htm http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1967.htm
kevin_thibedeau 6y ago
strtok_r() is everywhere and easy to retrofit. It's also easy to implement using strspn() and strcspn() if you don't have it.
icedchai 6y ago
This makes sense when you consider the history of C. Multi-threading was a relatively late add on, and outside of the standard library. When I learned C (early 90's), multi-threading wasn't even something you considered. It was either multiple processes or an event loop with select/poll.

loeg 6y ago

Re: getenv_s: Annex K is (still) optional. Compliant C11+ implementations may not have getenv_s.

josephcsible 6y ago
This is an understatement. The only relevant platform that supports Annex K is MSVC, and this is unlikely to change any time soon.
- loeg 6y ago
  And even MSVC does not actually implement the API specified in Annex K. Annex K was inspired by MSVC's design, but they diverged: > Microsoft Visual Studio implements an early version of the APIs. However, the implementation is incomplete and conforms neither to C11 nor to the original TR 24731-1. For example, it doesn't provide the set_constraint_handler_s function but instead defines a _invalid_parameter_handler _set_invalid_parameter_handler(_invalid_parameter_handler) function with similar behavior but a slightly different and incompatible signature. It also doesn't define the abort_handler_s and ignore_handler_s functions, the memset_s function (which isn't part of the TR), or the RSIZE_MAX macro.The Microsoft implementation also doesn't treat overlapping source and destination sequences as runtime-constraint violations and instead has undefined behavior in such cases. [0]: http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1967.htm http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1967.htm

kevin_thibedeau 6y ago

strtok_r() is everywhere and easy to retrofit. It's also easy to implement using strspn() and strcspn() if you don't have it.

icedchai 6y ago

This makes sense when you consider the history of C. Multi-threading was a relatively late add on, and outside of the standard library. When I learned C (early 90's), multi-threading wasn't even something you considered. It was either multiple processes or an event loop with select/poll.