.. default-domain:: chpl .. module:: SysBasic :synopsis: Types for low-level programming and C integration. SysBasic ======== **Usage** .. code-block:: chapel use SysBasic; Types for low-level programming and C integration. This module provides basic types when those types are not platform-dependent. The module :mod:`SysCTypes` contains the platform-dependent declarations for C compatibility. This module also defines the error types :type:`syserr` and :type:`err_t`. When should one use :type:`syserr` and when should one use :type:`err_t`? :type:`err_t` is a system error code (a `c_int` by a nicer name to indicate its purpose). :type:`syserr` is an enhanced error that might also include an error message. All user-facing Chapel library code, or user Chapel code, should generally use :type:`syserr`. When wrapping functions or declaring them in C, use :type:`err_t` to indicate that a function is returning an error code. A note about the error code documentation in this file. Error descriptions for system errors are included here for convenience only. Other documentation, such as system man pages or the POSIX specification are the authority on system error codes. .. type:: type c_float = real(32) The type corresponding to a C float .. type:: type c_double = real(64) The type corresponding to a C double .. type:: type off_t = int(64) The type corresponding to C's off_t .. type:: type mode_t = uint(32) The type corresponding to C's mode_t .. type:: type socklen_t = int(32) The type corresponding to C's socklen_t .. type:: type syserr A type storing an error code or an error message. A syserr can be compared using == or != to an err_t (ie integer error code) or to another syserr. A syserr can be cast to or from an err_t. It can be assigned the value of an err_t or another syserr. In addition, syserr can be checked directly in an if statement like so: .. code-block:: chapel var err: syserr; if err then do writeln("err contains an error, ie err != ENOERR"); if !err then do writeln("err does not contain an error; err == ENOERR"); When a :type:`syserr` formal has default intent, the actual is copied to the formal upon a function call and the formal cannot be assigned within the function. The default value of the :type:`syserr` type is undefined. .. type:: type err_t = c_int An integral error code. This is really just a `c_int`, but code is clearer if you use err_t to indicate arguments, variables, and return types that are system error codes. .. type:: type fd_t = c_int A system file descriptor. This is really just a `c_int`, but code is clearer if you use fd_t to indicate arguments, variables, and return types that are system file descriptors. .. function:: proc ENOERR The error code indicating that no error occurred (Chapel specific) .. function:: proc EEOF An error code indicating the end of file has been reached (Chapel specific) .. function:: proc ESHORT An error code indicating that the end of file or the end of the input was reached before the requested amount of data could be read. (Chapel specific) .. function:: proc EFORMAT An error code indicating a format error; for example when reading a quoted string literal, this would be returned if we never encountered the opening quote. (Chapel specific) .. data:: const E2BIG: err_t Argument list too long. The number of bytes used for the argument and environment list of the new process exceeded the current limit. (POSIX.1) .. data:: const EACCES: err_t Permission denied. An attempt was made to access a file in a way forbidden by its file access permissions. (POSIX.1) .. data:: const EADDRINUSE: err_t Address already in use. Only one usage of each address is normally permitted. (POSIX.1) .. data:: const EADDRNOTAVAIL: err_t Can't assign requested address. Normally results from an attempt to create a socket with an address not on this machine. (POSIX.1) .. data:: const EAFNOSUPPORT: err_t Address family not supported by protocol family. An address incompatible with the requested protocol was used. For example, you should not necessarily expect to be able to use NS addresses with ARPA Internet protocols. (POSIX.1) .. data:: const EAGAIN: err_t Resource temporarily unavailable. This is a temporary condition and later calls to the same routine may complete normally. (POSIX.1) .. data:: const EALREADY: err_t Operation already in progress. An operation was attempted on a non-blocking object that already had an operation in progress. (POSIX.1) .. data:: const EBADE: err_t Invalid exchange (linux only) .. data:: const EBADF: err_t Bad file descriptor. A file descriptor argument was out of range, referred to no open file, or a read (write) request was made to a file that was only open for writing (reading). (POSIX.1) .. data:: const EBADFD: err_t File descriptor in bad state (linux only) .. data:: const EBADMSG: err_t Bad message. A corrupted message was detected. (POSIX.1) .. data:: const EBADR: err_t Invalid request descriptor (linux only) .. data:: const EBADRQC: err_t Invalid request code (linux only) .. data:: const EBADSLT: err_t Invalid slot (linux only) .. data:: const EBUSY: err_t Device or resource busy. An attempt to use a system resource which was in use at the time in a manner which would have conflicted with the request. (POSIX.1) .. data:: const ECANCELED: err_t Operation canceled. The scheduled operation was canceled. (POSIX.1) .. data:: const ECHILD: err_t No child processes. A wait or waitpid system call was executed by a process that had no existing or unwaited-for child processes. (POSIX.1) .. data:: const ECHRNG: err_t Channel number out of range (linux only) .. data:: const ECOMM: err_t Communication error on send (linux only) .. data:: const ECONNABORTED: err_t Software caused connection abort. A connection abort was caused internal to your host machine. (POSIX.1) .. data:: const ECONNREFUSED: err_t Connection refused. No connection could be made because the target machine actively refused it. This usually results from trying to connect to a service that is inactive on the foreign host. (POSIX.1) .. data:: const ECONNRESET: err_t Connection reset by peer. A connection was forcibly closed by a peer. This normally results from a loss of the connection on the remote socket due to a timeout or a reboot. (POSIX.1) .. data:: const EDEADLK: err_t Resource deadlock avoided. An attempt was made to lock a system resource that would have resulted in a deadlock situation. (POSIX.1) .. data:: const EDESTADDRREQ: err_t Destination address required. A required address was omitted from an operation on a socket. (POSIX.1) .. data:: const EDOM: err_t Numerical argument out of domain. A numerical input argument was outside the defined domain of the mathematical function. (POSIX.1, C99) .. data:: const EDQUOT: err_t Disc quota exceeded. A write system call to an ordinary file, the creation of a directory or symbolic link, or the creation of a directory entry failed because the user's quota of disk blocks was exhausted, or the allocation of an inode for a newly created file failed because the user's quota of inodes was exhausted. (POSIX.1) .. data:: const EEXIST: err_t File exists. An existing file was mentioned in an inappropriate context, for instance, as the new link name in a link system call. (POSIX.1) .. data:: const EFAULT: err_t Bad address. The system detected an invalid address in attempting to use an argument of a call. (POSIX.1) .. data:: const EFBIG: err_t File too large. The size of a file exceeded the maximum. (POSIX.1) .. data:: const EHOSTDOWN: err_t Host is down. A socket operation failed because the destination host was down. (linux, FreeBSD) .. data:: const EHOSTUNREACH: err_t No route to host. A socket operation was attempted to an unreachable host. (POSIX.1) .. data:: const EIDRM: err_t Identifier removed. An IPC identifier was removed while the current process was waiting on it. (POSIX.1) .. data:: const EILSEQ: err_t Illegal byte sequence. While decoding a multibyte character the function came along an invalid or an incomplete sequence of bytes or the given wide character is invalid. This error might be returned for example in the case of an illegal UTF-8 byte sequence. (POSIX.1, C99) .. data:: const EINPROGRESS: err_t Operation now in progress. An operation that takes a long time to complete (such as a connect system call) was attempted on a non-blocking object. (POSIX.1) .. data:: const EINTR: err_t Interrupted system call. An asynchronous signal (such as SIGINT or SIGQUIT) was caught by the process during the execution of an interruptible function. If the signal handler performs a normal return, the interrupted system call will seem to have returned the error condition. (POSIX.1) .. data:: const EINVAL: err_t Invalid argument. Some invalid argument was supplied. (For example, specifying an undefined signal to a signal system call or a kill system call). (POSIX.1) .. data:: const EIO: err_t Input/output error. Some physical input or output error occurred. This error will not be reported until a subsequent operation on the same file descriptor and may be lost (over written) by any subsequent errors. (POSIX.1) .. data:: const EISCONN: err_t Socket is already connected. A connect system call was made on an already connected socket; or, a sendto or sendmsg system call on a connected socket specified a destination when already connected. (POSIX.1) .. data:: const EISDIR: err_t Is a directory. An attempt was made to open a directory with write mode specified. (POSIX.1) .. data:: const EISNAM: err_t Is a named type file (linux only) .. data:: const EKEYEXPIRED: err_t Key has expired (linux only) .. data:: const EKEYREJECTED: err_t Key was rejected by service (linux only) .. data:: const EKEYREVOKED: err_t Key has been revoked (linux only) .. data:: const EL2HLT: err_t Level 2 halted (linux only) .. data:: const EL2NSYNC: err_t Level 2 not synchronized (linux only) .. data:: const EL3HLT: err_t Level 3 halted (linux only) .. data:: const EL3RST: err_t Level 3 halted (linux only) .. data:: const ELIBACC: err_t Cannot access a needed shared library (linux only) .. data:: const ELIBBAD: err_t Accessing a corrupted shared library (linux only) .. data:: const ELIBMAX: err_t Attempting to link in too many shared libraries (linux only) .. data:: const ELIBSCN: err_t lib section in a.out corrupted (linux only) .. data:: const ELIBEXEC: err_t Cannot exec a shared library directly (linux only) .. data:: const ELOOP: err_t Too many levels of symbolic links. A path name lookup involved more than 32 (MAXSYMLINKS) symbolic links. (POSIX.1) .. data:: const EMEDIUMTYPE: err_t Wrong medium type (linux only) .. data:: const EMFILE: err_t Too many open files. Maximum number of file descriptors allowable in the process has been reached and requests for an open cannot be satisfied until at least one has been closed. The getdtablesize system call will obtain the current limit. (POSIX.1) .. data:: const EMLINK: err_t Too many links. Maximum allowable hard links to a single file has been exceeded. (POSIX.1) .. data:: const EMSGSIZE: err_t Message too long. A message sent on a socket was larger than the internal message buffer or some other network limit. (POSIX.1) .. data:: const EMULTIHOP: err_t Multihop attempted. (POSIX.1) .. data:: const ENAMETOOLONG: err_t File name too long. A component of a path name exceeded {NAME_MAX} characters, or an entire path name exceeded {PATH_MAX} characters. (POSIX.1) .. data:: const ENETDOWN: err_t Network is down. A socket operation encountered a dead network. (POSIX.1) .. data:: const ENETRESET: err_t Network dropped connection on reset. The host you were connected to crashed and rebooted. (POSIX.1) .. data:: const ENETUNREACH: err_t Network is unreachable. A socket operation was attempted to an unreachable network. (POSIX.1) .. data:: const ENFILE: err_t Too many open files in system. Maximum number of open files allowable on the system has been reached and requests for an open cannot be satisfied until at least one has been closed. (POSIX.1) .. data:: const ENOBUFS: err_t No buffer space available. An operation on a socket or pipe was not performed because the system lacked sufficient buffer space or because a queue was full. (POSIX.1 XSI STREAMS option) .. data:: const ENODATA: err_t No message is available on the STREAM head read queue (POSIX.1) .. data:: const ENODEV: err_t Operation not supported by device. An attempt was made to apply an inappropriate function to a device, for example, trying to read a write-only device such as a printer. (POSIX.1) .. data:: const ENOENT: err_t No such file or directory. A component of a specified pathname did not exist, or the pathname was an empty string. (POSIX.1) .. data:: const ENOEXEC: err_t Exec format error. A request was made to execute a file that, although it has the appropriate permissions, was not in the format required for an executable file. (POSIX.1) .. data:: const ENOKEY: err_t Required key not available (linux only) .. data:: const ENOLCK: err_t No locks available. A system-imposed limit on the number of simultaneous file locks was reached. (POSIX.1) .. data:: const ENOLINK: err_t Link has been severed. (POSIX.1) .. data:: const ENOMEDIUM: err_t No medium found (linux only) .. data:: const ENOMEM: err_t Cannot allocate memory. The new process image required more memory than was allowed by the hardware or by system-imposed memory management constraints. A lack of swap space is normally temporary; however, a lack of core is not. Soft limits may be increased to their corresponding hard limits. (POSIX.1) .. data:: const ENOMSG: err_t No message of desired type. An IPC message queue does not contain a message of the desired type, or a message catalog does not contain the requested message. (POSIX.1) .. data:: const ENONET: err_t Machine is not on the network (linux only) .. data:: const ENOPKG: err_t Package not installed (linux only) .. data:: const ENOPROTOOPT: err_t Protocol not available. A bad option or level was specified in a getsockopt or setsockopt system call. (POSIX.1) .. data:: const ENOSPC: err_t No space left on device. A write system call to an ordinary file, the creation of a directory or symbolic link, or the creation of a directory entry failed because no more disk blocks were available on the file system, or the allocation of an inode for a newly created file failed because no more inodes were available on the file system. (POSIX.1) .. data:: const ENOSR: err_t No STREAM resources (POSIX.1 XSI STREAMS option) .. data:: const ENOSTR: err_t Not a STREAM (POSIX.1 XSI STREAMS option) .. data:: const ENOSYS: err_t Function not implemented. Attempted a system call that is not available on this system. (POSIX.1) .. data:: const ENOTBLK: err_t Block device required. A block device operation was attempted on a non-block device or file. (linux, FreeBSD) .. data:: const ENOTCONN: err_t Socket is not connected. An request to send or receive data was disallowed because the socket was not connected and (when sending on a datagram socket) no address was supplied. (POSIX.1) .. data:: const ENOTDIR: err_t Not a directory. A component of the specified pathname existed, but it was not a directory, when a directory was expected. (POSIX.1) .. data:: const ENOTEMPTY: err_t Directory not empty. A directory with entries other than '.' and '..' was supplied to a remove directory or rename call. (POSIX.1) .. data:: const ENOTSOCK: err_t Socket operation on non-socket. (POSIX.1) .. data:: const ENOTSUP: err_t Operation not supported. The attempted operation is not supported for the type of object referenced. Usually this occurs when a file descriptor refers to a file or socket that cannot support this operation, for example, trying to accept a connection on a datagram socket. (POSIX.1) .. data:: const ENOTTY: err_t Inappropriate ioctl for device. A control function (e.g. ioctl system call) was attempted for a file or special device for which the operation was inappropriate. (POSIX.1) .. data:: const ENOTUNIQ: err_t Name not unique on network (linux only) .. data:: const ENXIO: err_t Device not configured. Input or output on a special file referred to a device that did not exist, or made a request beyond the limits of the device. This error may also occur when, for example, a tape drive is not online or no disk pack is loaded on a drive. (POSIX.1) .. data:: const EOPNOTSUPP: err_t Operation not supported. The attempted operation is not supported for the type of object referenced. Usually this occurs when a file descriptor refers to a file or socket that cannot support this operation, for example, trying to accept a connection on a datagram socket. (POSIX.1) .. data:: const EOVERFLOW: err_t Value too large to be stored in data type. A numerical result of the function was too large to be stored in the caller provided space. (POSIX.1) .. data:: const EPERM: err_t Operation not permitted. An attempt was made to perform an operation limited to processes with appropriate privileges or to the owner of a file or other resources. (POSIX.1) .. data:: const EPFNOSUPPORT: err_t Protocol family not supported. The protocol family has not been configured into the system or no implementation for it exists. (linux, FreeBSD) .. data:: const EPIPE: err_t Broken pipe. A write on a pipe, socket or FIFO for which there is no process to read the data. (POSIX.1) .. data:: const EPROTO: err_t Protocol error. A device or socket encountered an unrecoverable protocol error. (POSIX.1) .. data:: const EPROTONOSUPPORT: err_t Protocol not supported. The protocol has not been configured into the system or no implementation for it exists. (POSIX.1) .. data:: const EPROTOTYPE: err_t Protocol wrong type for socket. A protocol was specified that does not sup- port the semantics of the socket type requested. For example, you cannot use the ARPA Internet UDP protocol with type SOCK_STREAM. (POSIX.1) .. data:: const ERANGE: err_t Result too large. A numerical result of the function was too large to fit in the available space (perhaps exceeded precision). (POSIX.1, C99) .. data:: const EREMCHG: err_t Remote address changed (linux only) .. data:: const EREMOTE: err_t Object is remote (linux only) .. data:: const EREMOTEIO: err_t Remote I/O error (linux only) .. data:: const ERESTART: err_t Interrupted system call should be restarted (linux only) .. data:: const EROFS: err_t Read-only file system. An attempt was made to modify a file or directory on a file system that was read-only at the time. (POSIX.1) .. data:: const ESHUTDOWN: err_t Can't send after socket shutdown. A request to send data was disallowed because the socket had already been shut down with a previous shutdown system call. .. data:: const ESPIPE: err_t Illegal seek. An lseek system call was issued on a socket, pipe or FIFO. (POSIX.1) .. data:: const ESOCKTNOSUPPORT: err_t Socket type not supported. The support for the socket type has not been configured into the system or no implementation for it exists. (linux, FreeBSD) .. data:: const ESRCH: err_t No such process. No process could be found corresponding to that specified by the given process ID. (POSIX.1) .. data:: const ESTALE: err_t Stale NFS file handle. An attempt was made to access an open file (on an NFS file system) which is now unavailable as referenced by the file descriptor. This may indicate the file was deleted on the NFS server or some other catastrophic event occurred. (POSIX.1) .. data:: const ESTRPIPE: err_t Streams pipe error (linux only) .. data:: const ETIME: err_t Timer expired (POSIX.1 XSI STREAMS option) .. data:: const ETIMEDOUT: err_t Operation timed out. A connect or send system call failed because the connected party did not properly respond after a period of time. (The timeout period is dependent on the communication protocol.) (POSIX.1) .. data:: const ETXTBSY: err_t Text file busy. The new process was a pure procedure (shared text) file which was open for writing by another process, or while the pure procedure file was being executed an open system call requested write access. (POSIX.1) .. data:: const EUCLEAN: err_t Structure needs cleaning (linux only) .. data:: const EUNATCH: err_t Protocol driver not attached (linux only) .. data:: const EUSERS: err_t Too many users. The quota system ran out of table entries. (linux, FreeBSD) .. data:: const EWOULDBLOCK: err_t Operation would block (may be same value as EAGAIN) (POSIX.1) .. data:: const EXDEV: err_t Cross-device link. A hard link to a file on another file system was attempted. (POSIX.1) .. data:: const EXFULL: err_t Exchange full (linux only)