Comprehensive errno type covering Linux, BSD, macOS, and Windows values

Convert errno code to variant

Convert variant to errno code

Get current errno value

Get current errno as int

Reset errno to 0

Generic error-raising function.

raise_on_error ?call f check calls f() and checks the result with check. If check returns true, raises a Unix_error based on the current errno.

• parameter call

  Optional name of the calling function (for error messages)

• parameter f

  Function to execute

• parameter check

  Function to check if result indicates an error

• returns

  The result of f() if no error occurred

• raises Unix_error

  if check returns true

Check for negative integer return (common for syscalls). Raises Unix_error if result < 0.

Check for null pointer return (for C functions). Raises Unix_error if result is null.

Check for zero return value (some functions return 0 on error). Raises Unix_error if result = 0.

Check for None return value. Raise Unix_error if result = None.

Convert errno variant to Unix.error

Convert errno int to Unix.error

Get error message string for an errno value using strerror. This function is cross-platform (works on both POSIX and Windows) but not thread-safe.

• parameter errnum

  The errno value to get the message for

• returns

  Error message string

Get error message string for an errno value using strerror_r. This function is thread-safe but only available on POSIX systems.

• parameter buflen

  Optional buffer length for error message (default: 1024)

• parameter errn

  The errno value to get the message for

• returns

  Error message string

• raises Invalid_argument

  on Windows where strerror_r is not available

• raises Unix_error

  if strerror_r fails

Check if an errno value is natively defined on this platform. Returns true if the errno is natively defined by the system, false if it's using a placeholder fallback value.

This is useful to determine if an errno constant represents a real system error on the current platform, or if it's just a placeholder value (typically in the 10000+ range) that was assigned because the error doesn't exist on this system.

• parameter errnum

  The errno value to check

• returns

  true if natively defined, false if using placeholder