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# Include file that implements 'osErrorMsg' and friends. Do not import it!
when not declared(os) and not declared(ospaths):
{.error: "This is an include file for os.nim!".}
when not defined(nimscript):
var errno {.importc, header: "<errno.h>".}: cint
proc c_strerror(errnum: cint): cstring {.
importc: "strerror", header: "<string.h>".}
when defined(windows):
import winlean
proc `==`*(err1, err2: OSErrorCode): bool {.borrow.}
proc `$`*(err: OSErrorCode): string {.borrow.}
proc osErrorMsg*(errorCode: OSErrorCode): string =
## Converts an OS error code into a human readable string.
##
## The error code can be retrieved using the `osLastError proc <#osLastError>`_.
##
## If conversion fails, or ``errorCode`` is ``0`` then ``""`` will be
## returned.
##
## On Windows, the ``-d:useWinAnsi`` compilation flag can be used to
## make this procedure use the non-unicode Win API calls to retrieve the
## message.
##
## See also:
## * `raiseOSError proc <#raiseOSError,OSErrorCode,string>`_
## * `osLastError proc <#osLastError>`_
runnableExamples:
when defined(linux):
assert osErrorMsg(OSErrorCode(0)) == ""
assert osErrorMsg(OSErrorCode(1)) == "Operation not permitted"
assert osErrorMsg(OSErrorCode(2)) == "No such file or directory"
result = ""
when defined(nimscript):
discard
elif defined(Windows):
if errorCode != OSErrorCode(0'i32):
when useWinUnicode:
var msgbuf: WideCString
if formatMessageW(0x00000100 or 0x00001000 or 0x00000200,
nil, errorCode.int32, 0, addr(msgbuf), 0, nil) != 0'i32:
result = $msgbuf
if msgbuf != nil: localFree(cast[pointer](msgbuf))
else:
var msgbuf: cstring
if formatMessageA(0x00000100 or 0x00001000 or 0x00000200,
nil, errorCode.int32, 0, addr(msgbuf), 0, nil) != 0'i32:
result = $msgbuf
if msgbuf != nil: localFree(msgbuf)
else:
if errorCode != OSErrorCode(0'i32):
result = $c_strerror(errorCode.int32)
proc newOSError*(
errorCode: OSErrorCode, additionalInfo = ""
): owned(ref OSError) {.noinline.} =
## Creates a new `OSError exception <system.html#OSError>`_.
##
## The ``errorCode`` will determine the
## message, `osErrorMsg proc <#osErrorMsg,OSErrorCode>`_ will be used
## to get this message.
##
## The error code can be retrieved using the `osLastError proc
## <#osLastError>`_.
##
## If the error code is ``0`` or an error message could not be retrieved,
## the message ``unknown OS error`` will be used.
##
## See also:
## * `osErrorMsg proc <#osErrorMsg,OSErrorCode>`_
## * `osLastError proc <#osLastError>`_
var e: owned(ref OSError); new(e)
e.errorCode = errorCode.int32
e.msg = osErrorMsg(errorCode)
if additionalInfo.len > 0:
if e.msg.len > 0 and e.msg[^1] != '\n': e.msg.add '\n'
e.msg.add "Additional info: "
e.msg.addQuoted additionalInfo
if e.msg == "":
e.msg = "unknown OS error"
return e
proc raiseOSError*(errorCode: OSErrorCode, additionalInfo = "") {.noinline.} =
## Raises an `OSError exception <system.html#OSError>`_.
##
## Read the description of the `newOSError proc <#newOSError,OSErrorCode,string>`_ to learn
## how the exception object is created.
raise newOSError(errorCode, additionalInfo)
{.push stackTrace:off.}
proc osLastError*(): OSErrorCode {.sideEffect.} =
## Retrieves the last operating system error code.
##
## This procedure is useful in the event when an OS call fails. In that case
## this procedure will return the error code describing the reason why the
## OS call failed. The ``OSErrorMsg`` procedure can then be used to convert
## this code into a string.
##
## **Warning**:
## The behaviour of this procedure varies between Windows and POSIX systems.
## On Windows some OS calls can reset the error code to ``0`` causing this
## procedure to return ``0``. It is therefore advised to call this procedure
## immediately after an OS call fails. On POSIX systems this is not a problem.
##
## See also:
## * `osErrorMsg proc <#osErrorMsg,OSErrorCode>`_
## * `raiseOSError proc <#raiseOSError,OSErrorCode,string>`_
when defined(nimscript):
discard
elif defined(windows):
result = OSErrorCode(getLastError())
else:
result = OSErrorCode(errno)
{.pop.}
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