The Standard ML Basis Library

The `Posix.Error` structure

Synopsis

signature POSIX_ERROR structure Error : POSIX_ERROR

The structure Posix.Error provides symbolic names for errors that may be generated by the POSIX library, and various related functions.

Interface

eqtype syserror = OS.Process.syserror val toWord : syserror -> SysWord.word val fromWord : SysWord.word -> syserror val errorMsg : syserror -> string val errorName : syserror -> string val syserror : string -> syserror option val acces : syserror val again : syserror val badf : syserror val badmsg : syserror val busy : syserror val canceled : syserror val child : syserror val deadlk : syserror val dom : syserror val exist : syserror val fault : syserror val fbig : syserror val inprogress : syserror val intr : syserror val inval : syserror val io : syserror val isdir : syserror val loop : syserror val mfile : syserror val mlink : syserror val msgsize : syserror val nametoolong : syserror val nfile : syserror val nodev : syserror val noent : syserror val noexec : syserror val nolck : syserror val nomem : syserror val nospc : syserror val nosys : syserror val notdir : syserror val notempty : syserror val notsup : syserror val notty : syserror val nxio : syserror val perm : syserror val pipe : syserror val range : syserror val rofs : syserror val spipe : syserror val srch : syserror val toobig : syserror val xdev : syserror

Description

eqtype syserror = OS.Process.syserror: POSIX error type. This is identical to the type OS.syserror.
val toWord : syserror -> SysWord.word val fromWord : SysWord.word -> syserror: These functions convert between syserror values and non-zero word representations. Note that there is no validation that a syserror value generated using fromWord corresponds to an error value supported by the underlying system.

errorMsg sy: returns a string that describes the system error sy.

errorName err: returns a unique name used for the syserror value.

syserror s: returns the syserror whose name is s if it exists. If e is a syserror, we have SOME(e) = syserror(errorName e).

Discussion

The values defined in this structure represent the standard POSIX errors. The following table provides a brief description of their meanings:

SML name	Description
`acces`	An attempt was made to access a file in a way that is forbidden by its file access permissions.
`again`	A resource is temporarily unavailable, and later calls to the same routine may complete normally.
`badf`	A bad file descriptor was out of range or referred to no open file, or a read (write) request was made to a file which was only open for writing (reading).
`badmsg`	The implementation has detected a corrupted message.
`busy`	An attempt was made to use a system resource that was being used in a conflicting manner by another process.
`canceled`	The associated asynchronous operation was canceled before completion.
`child`	A `wait` related function was executed by a process that had no existing or unwaited-for child process.
`deadlk`	An attempt was made to lock a system resource which would have resulted in a deadlock situation.
`dom`	An input argument was outside the defined domain of a mathematical function.
`exist`	An existing file was specified in an inappropriate context; for instance, as the new link in a `link` function.
`fault`	The system detected an invalid address in attempting to use an argument of a system call.
`fbig`	The size of a file would exceed an implementation-defined maximum file size.
`inprogress`	An asynchronous process has not yet completed.
`intr`	An asynchronous signal (such as a `quit` or a `term` (terminate) signal) was caught by the process during the execution of an interruptible function.
`inval`	An invalid argument was supplied.
`io`	Some physical input or output error occurred.
`isdir`	An illegal operation was attempted on a directory, such as opening a directory for writing.
`loop`	A loop was encountered during pathname resolution due to symbolic links.
`mfile`	An attempt was made to open more than the maximum number of file descriptors allowed in this process.
`mlink`	An attempt was made to have the link count of a single file exceed a system-dependent limit.
`msgsize`	An inappropriate message buffer length was used.
`nametoolong`	The size of a pathname string, or a pathname component, was longer than the system-dependent limit.
`nfile`	There were too many open files.
`nodev`	An attempt was made to apply an inappropriate function to a device; for example, trying to read from a write-only device such as a printer.
`noent`	A component of a specified pathname did not exist, or the pathname was an empty string.
`noexec`	A request was made to execute a file that, although it had the appropriate permissions, was not in the format required by the implementation for executable files.
`nolck`	A system-imposed limit on the number of simultaneous file and record locks was reached.
`nomem`	The process image required more memory than was allowed by the hardware or by system-imposed memory management constraints.
`nospc`	During a `write` operation on a regular file, or when extending a directory, there was no free space left on the device.
`nosys`	An attempt was made to use a function that is not available in this implementation.
`notdir`	A component of the specified pathname existed, but it was not a directory, when a directory was expected.
`notempty`	A directory with entries other than `"."` and `".."` was supplied when an empty directory was expected.
`notsup`	The implementation does not support this feature of the standard.
`notty`	A control function was attempted for a file or a special file for which the operation was inappropriate.
`nxio`	Input or output on a special file referred to a device which did not exist, or made a request beyond the limits of the device. This error may occur when, for example, a tape drive is not online.
`perm`	An attempt was made to perform an operation limited to processes with appropriate privileges or to the owner of a file or some other resource.
`pipe`	A write was attempted on a pipe or FIFO for which there was no process to read the data.
`range`	The result of a function was too large to fit in the available space.
`rofs`	An attempt was made to modify a file or directory on a file system which was read-only at that time.
`spipe`	An invalid seek operation was issued on a pipe or FIFO.
`srch`	No such process could be found corresponding to that specified by a given process ID.
`toobig`	The sum of bytes used by the argument list and environment list was greater than the system-imposed limit.
`xdev`	A link to a file on another file system was attempted.

The string representation of a syserror value, as returned by errorName, is the name of the error. Thus,

errorName
badmsg = "badmsg"

The name of a corresponding POSIX error can be derived by capitalizing all letters and adding the character ``E'' as a prefix. For example, the POSIX error associated with nodev is ENODEV. The only exception to this rule is the error toobig, whose associated POSIX error is E2BIG.

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Generated April 12, 2004
Last Modified July 1, 2002
Comments to John Reppy.

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