C Programming/string.h/strerror

The string-error function, strerror, is a C/C++ function which translates an error code, usually stored in the global variable errno, to a human-readable error message.

History
The strerror function is defined in IEEE Std 1003.1, also known as POSIX 1.

Reentrancy
The strerror function is not reentrant. For a reentrant version of the function, see strerror r.

Semantics
The function generates and reports a C-style string, containing an error message derived from the error code passed in with errnum.