Constant |
Description |
SIGHUP |
Sent to indicate when a controlling terminal is closed or a parent
process exits. |
SIGINT |
Sent to indicate when a user wishes to interrupt a process
(Ctrl+C). |
SIGQUIT |
Sent to indicate when a user wishes to terminate a process and perform a
core dump. |
SIGILL |
Sent to a process to notify that it has attempted to perform an illegal,
malformed, unknown, or privileged instruction. |
SIGTRAP |
Sent to a process when an exception has occurred. |
SIGABRT |
Sent to a process to request that it abort. |
SIGIOT |
Synonym for SIGABRT |
SIGBUS |
Sent to a process to notify that it has caused a bus error. |
SIGFPE |
Sent to a process to notify that it has performed an illegal arithmetic
operation. |
SIGKILL |
Sent to a process to terminate it immediately. |
SIGUSR1 SIGUSR2 |
Sent to a process to identify user-defined conditions. |
SIGSEGV |
Sent to a process to notify of a segmentation fault. |
SIGPIPE |
Sent to a process when it has attempted to write to a disconnected
pipe. |
SIGALRM |
Sent to a process when a system timer elapses. |
SIGTERM |
Sent to a process to request termination. |
SIGCHLD |
Sent to a process when a child process terminates. |
SIGSTKFLT |
Sent to a process to indicate a stack fault on a coprocessor. |
SIGCONT |
Sent to instruct the operating system to continue a paused process. |
SIGSTOP |
Sent to instruct the operating system to halt a process. |
SIGTSTP |
Sent to a process to request it to stop. |
SIGBREAK |
Sent to indicate when a user wishes to interrupt a process. |
SIGTTIN |
Sent to a process when it reads from the TTY while in the
background. |
SIGTTOU |
Sent to a process when it writes to the TTY while in the
background. |
SIGURG |
Sent to a process when a socket has urgent data to read. |
SIGXCPU |
Sent to a process when it has exceeded its limit on CPU usage. |
SIGXFSZ |
Sent to a process when it grows a file larger than the maximum
allowed. |
SIGVTALRM |
Sent to a process when a virtual timer has elapsed. |
SIGPROF |
Sent to a process when a system timer has elapsed. |
SIGWINCH |
Sent to a process when the controlling terminal has changed its
size. |
SIGIO |
Sent to a process when I/O is available. |
SIGPOLL |
Synonym for SIGIO |
SIGLOST |
Sent to a process when a file lock has been lost. |
SIGPWR |
Sent to a process to notify of a power failure. |
SIGINFO |
Synonym for SIGPWR |
SIGSYS |
Sent to a process to notify of a bad argument. |
SIGUNUSED |
Synonym for SIGSYS |
### Error constants
The following error constants are exported by `os.constants.errno`.
#### POSIX error constants
Constant |
Description |
E2BIG |
Indicates that the list of arguments is longer than expected. |
EACCES |
Indicates that the operation did not have sufficient permissions. |
EADDRINUSE |
Indicates that the network address is already in use. |
EADDRNOTAVAIL |
Indicates that the network address is currently unavailable for
use. |
EAFNOSUPPORT |
Indicates that the network address family is not supported. |
EAGAIN |
Indicates that there is no data available and to try the
operation again later. |
EALREADY |
Indicates that the socket already has a pending connection in
progress. |
EBADF |
Indicates that a file descriptor is not valid. |
EBADMSG |
Indicates an invalid data message. |
EBUSY |
Indicates that a device or resource is busy. |
ECANCELED |
Indicates that an operation was canceled. |
ECHILD |
Indicates that there are no child processes. |
ECONNABORTED |
Indicates that the network connection has been aborted. |
ECONNREFUSED |
Indicates that the network connection has been refused. |
ECONNRESET |
Indicates that the network connection has been reset. |
EDEADLK |
Indicates that a resource deadlock has been avoided. |
EDESTADDRREQ |
Indicates that a destination address is required. |
EDOM |
Indicates that an argument is out of the domain of the function. |
EDQUOT |
Indicates that the disk quota has been exceeded. |
EEXIST |
Indicates that the file already exists. |
EFAULT |
Indicates an invalid pointer address. |
EFBIG |
Indicates that the file is too large. |
EHOSTUNREACH |
Indicates that the host is unreachable. |
EIDRM |
Indicates that the identifier has been removed. |
EILSEQ |
Indicates an illegal byte sequence. |
EINPROGRESS |
Indicates that an operation is already in progress. |
EINTR |
Indicates that a function call was interrupted. |
EINVAL |
Indicates that an invalid argument was provided. |
EIO |
Indicates an otherwise unspecified I/O error. |
EISCONN |
Indicates that the socket is connected. |
EISDIR |
Indicates that the path is a directory. |
ELOOP |
Indicates too many levels of symbolic links in a path. |
EMFILE |
Indicates that there are too many open files. |
EMLINK |
Indicates that there are too many hard links to a file. |
EMSGSIZE |
Indicates that the provided message is too long. |
EMULTIHOP |
Indicates that a multihop was attempted. |
ENAMETOOLONG |
Indicates that the filename is too long. |
ENETDOWN |
Indicates that the network is down. |
ENETRESET |
Indicates that the connection has been aborted by the network. |
ENETUNREACH |
Indicates that the network is unreachable. |
ENFILE |
Indicates too many open files in the system. |
ENOBUFS |
Indicates that no buffer space is available. |
ENODATA |
Indicates that no message is available on the stream head read
queue. |
ENODEV |
Indicates that there is no such device. |
ENOENT |
Indicates that there is no such file or directory. |
ENOEXEC |
Indicates an exec format error. |
ENOLCK |
Indicates that there are no locks available. |
ENOLINK |
Indications that a link has been severed. |
ENOMEM |
Indicates that there is not enough space. |
ENOMSG |
Indicates that there is no message of the desired type. |
ENOPROTOOPT |
Indicates that a given protocol is not available. |
ENOSPC |
Indicates that there is no space available on the device. |
ENOSR |
Indicates that there are no stream resources available. |
ENOSTR |
Indicates that a given resource is not a stream. |
ENOSYS |
Indicates that a function has not been implemented. |
ENOTCONN |
Indicates that the socket is not connected. |
ENOTDIR |
Indicates that the path is not a directory. |
ENOTEMPTY |
Indicates that the directory is not empty. |
ENOTSOCK |
Indicates that the given item is not a socket. |
ENOTSUP |
Indicates that a given operation is not supported. |
ENOTTY |
Indicates an inappropriate I/O control operation. |
ENXIO |
Indicates no such device or address. |
EOPNOTSUPP |
Indicates that an operation is not supported on the socket. Although
ENOTSUP and EOPNOTSUPP have the same value
on Linux, according to POSIX.1 these error values should be distinct.) |
EOVERFLOW |
Indicates that a value is too large to be stored in a given data
type. |
EPERM |
Indicates that the operation is not permitted. |
EPIPE |
Indicates a broken pipe. |
EPROTO |
Indicates a protocol error. |
EPROTONOSUPPORT |
Indicates that a protocol is not supported. |
EPROTOTYPE |
Indicates the wrong type of protocol for a socket. |
ERANGE |
Indicates that the results are too large. |
EROFS |
Indicates that the file system is read only. |
ESPIPE |
Indicates an invalid seek operation. |
ESRCH |
Indicates that there is no such process. |
ESTALE |
Indicates that the file handle is stale. |
ETIME |
Indicates an expired timer. |
ETIMEDOUT |
Indicates that the connection timed out. |
ETXTBSY |
Indicates that a text file is busy. |
EWOULDBLOCK |
Indicates that the operation would block. |
EXDEV |
Indicates an improper link. |
#### Windows-specific error constants
The following error codes are specific to the Windows operating system.
Constant |
Description |
WSAEINTR |
Indicates an interrupted function call. |
WSAEBADF |
Indicates an invalid file handle. |
WSAEACCES |
Indicates insufficient permissions to complete the operation. |
WSAEFAULT |
Indicates an invalid pointer address. |
WSAEINVAL |
Indicates that an invalid argument was passed. |
WSAEMFILE |
Indicates that there are too many open files. |
WSAEWOULDBLOCK |
Indicates that a resource is temporarily unavailable. |
WSAEINPROGRESS |
Indicates that an operation is currently in progress. |
WSAEALREADY |
Indicates that an operation is already in progress. |
WSAENOTSOCK |
Indicates that the resource is not a socket. |
WSAEDESTADDRREQ |
Indicates that a destination address is required. |
WSAEMSGSIZE |
Indicates that the message size is too long. |
WSAEPROTOTYPE |
Indicates the wrong protocol type for the socket. |
WSAENOPROTOOPT |
Indicates a bad protocol option. |
WSAEPROTONOSUPPORT |
Indicates that the protocol is not supported. |
WSAESOCKTNOSUPPORT |
Indicates that the socket type is not supported. |
WSAEOPNOTSUPP |
Indicates that the operation is not supported. |
WSAEPFNOSUPPORT |
Indicates that the protocol family is not supported. |
WSAEAFNOSUPPORT |
Indicates that the address family is not supported. |
WSAEADDRINUSE |
Indicates that the network address is already in use. |
WSAEADDRNOTAVAIL |
Indicates that the network address is not available. |
WSAENETDOWN |
Indicates that the network is down. |
WSAENETUNREACH |
Indicates that the network is unreachable. |
WSAENETRESET |
Indicates that the network connection has been reset. |
WSAECONNABORTED |
Indicates that the connection has been aborted. |
WSAECONNRESET |
Indicates that the connection has been reset by the peer. |
WSAENOBUFS |
Indicates that there is no buffer space available. |
WSAEISCONN |
Indicates that the socket is already connected. |
WSAENOTCONN |
Indicates that the socket is not connected. |
WSAESHUTDOWN |
Indicates that data cannot be sent after the socket has been
shutdown. |
WSAETOOMANYREFS |
Indicates that there are too many references. |
WSAETIMEDOUT |
Indicates that the connection has timed out. |
WSAECONNREFUSED |
Indicates that the connection has been refused. |
WSAELOOP |
Indicates that a name cannot be translated. |
WSAENAMETOOLONG |
Indicates that a name was too long. |
WSAEHOSTDOWN |
Indicates that a network host is down. |
WSAEHOSTUNREACH |
Indicates that there is no route to a network host. |
WSAENOTEMPTY |
Indicates that the directory is not empty. |
WSAEPROCLIM |
Indicates that there are too many processes. |
WSAEUSERS |
Indicates that the user quota has been exceeded. |
WSAEDQUOT |
Indicates that the disk quota has been exceeded. |
WSAESTALE |
Indicates a stale file handle reference. |
WSAEREMOTE |
Indicates that the item is remote. |
WSASYSNOTREADY |
Indicates that the network subsystem is not ready. |
WSAVERNOTSUPPORTED |
Indicates that the winsock.dll version is out of
range. |
WSANOTINITIALISED |
Indicates that successful WSAStartup has not yet been performed. |
WSAEDISCON |
Indicates that a graceful shutdown is in progress. |
WSAENOMORE |
Indicates that there are no more results. |
WSAECANCELLED |
Indicates that an operation has been canceled. |
WSAEINVALIDPROCTABLE |
Indicates that the procedure call table is invalid. |
WSAEINVALIDPROVIDER |
Indicates an invalid service provider. |
WSAEPROVIDERFAILEDINIT |
Indicates that the service provider failed to initialized. |
WSASYSCALLFAILURE |
Indicates a system call failure. |
WSASERVICE_NOT_FOUND |
Indicates that a service was not found. |
WSATYPE_NOT_FOUND |
Indicates that a class type was not found. |
WSA_E_NO_MORE |
Indicates that there are no more results. |
WSA_E_CANCELLED |
Indicates that the call was canceled. |
WSAEREFUSED |
Indicates that a database query was refused. |
### dlopen constants
If available on the operating system, the following constants
are exported in `os.constants.dlopen`. See dlopen(3) for detailed
information.