aa12cea2cc
Although groff_mdoc(7) gives another impression, this is the ordering most widely used and also required by mdocml/mandoc. Reviewed by: ru Approved by: philip, ed (mentors)
108 lines
3.5 KiB
Groff
108 lines
3.5 KiB
Groff
.\" Copyright (c) 2006 Joseph Koshy. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" This software is provided by Joseph Koshy ``as is'' and
|
|
.\" any express or implied warranties, including, but not limited to, the
|
|
.\" implied warranties of merchantability and fitness for a particular purpose
|
|
.\" are disclaimed. in no event shall Joseph Koshy be liable
|
|
.\" for any direct, indirect, incidental, special, exemplary, or consequential
|
|
.\" damages (including, but not limited to, procurement of substitute goods
|
|
.\" or services; loss of use, data, or profits; or business interruption)
|
|
.\" however caused and on any theory of liability, whether in contract, strict
|
|
.\" liability, or tort (including negligence or otherwise) arising in any way
|
|
.\" out of the use of this software, even if advised of the possibility of
|
|
.\" such damage.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd June 11, 2006
|
|
.Dt ELF_ERRMSG 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm elf_errmsg ,
|
|
.Nm elf_errno
|
|
.Nd ELF library error message handling
|
|
.Sh LIBRARY
|
|
.Lb libelf
|
|
.Sh SYNOPSIS
|
|
.In libelf.h
|
|
.Ft int
|
|
.Fn elf_errno "void"
|
|
.Ft "const char *"
|
|
.Fn elf_errmsg "int error"
|
|
.Sh DESCRIPTION
|
|
When an error occurs during an ELF library API call, the library
|
|
encodes the error using an error number and stores the error number
|
|
internally for retrieval by the application at a later point of time.
|
|
Error numbers may contain an OS supplied error code in addition to
|
|
an ELF API specific error code.
|
|
An error number value of zero indicates no error.
|
|
.Pp
|
|
Function
|
|
.Fn elf_errno
|
|
is used to retrieve the last error recorded by the ELF library.
|
|
Invoking this function has the side-effect of resetting the
|
|
ELF library's recorded error number to zero.
|
|
.Pp
|
|
The function
|
|
.Fn elf_errmsg
|
|
returns a null-terminated string with a human readable
|
|
description of the error specified in argument
|
|
.Ar error .
|
|
A zero value for argument
|
|
.Ar error
|
|
retrieves the most recent error encountered by the ELF
|
|
library.
|
|
An argument value of -1 behaves identically, except that
|
|
it guarantees a non-NULL return from
|
|
.Fn elf_errmsg .
|
|
.Sh RETURN VALUES
|
|
Function
|
|
.Fn elf_errno
|
|
returns a non-zero value encoding the last error encountered
|
|
by the ELF library, or zero if no error was encountered.
|
|
.Pp
|
|
Function
|
|
.Fn elf_errmsg
|
|
returns a pointer to library local storage for non-zero values
|
|
of argument
|
|
.Ar error .
|
|
With a zero argument, the function will return a NULL pointer if no
|
|
error had been encountered by the library, or will return a pointer to
|
|
library local storage containing an appropriate message otherwise.
|
|
.Sh EXAMPLES
|
|
Clearing the ELF library's recorded error number can be accomplished
|
|
by invoking
|
|
.Fn elf_errno
|
|
and discarding its return value.
|
|
.Bd -literal -offset indent
|
|
/* clear error */
|
|
(void) elf_errno();
|
|
.Ed
|
|
.Pp
|
|
Retrieving a human-readable description of the current error number
|
|
can be done with the following snippet:
|
|
.Bd -literal -offset indent
|
|
int err;
|
|
const char *errmsg;
|
|
\&...
|
|
err = elf_errno();
|
|
if (err != 0)
|
|
errmsg = elf_errmsg(err);
|
|
.Ed
|
|
.Sh SEE ALSO
|
|
.Xr elf 3 ,
|
|
.Xr gelf 3
|
|
.Sh BUGS
|
|
Function
|
|
.Fn elf_errmsg
|
|
is not localized.
|