0d8c6e9661
dblatex -t pdf ./comedilib.xml There were two major issues in the comedilb.xml: 1) there were too many nested sections so that latex ran out of sub-sub-sub-sub-sections. 2) A section needs a title and can no longer exist without one. The first line of the textfiles contains now the title and will be inserted by mkref into the xml file. todo: switch from xmlto to dblatex for the pdf generation and re-enable it in the makefile.
130 lines
4.5 KiB
Text
130 lines
4.5 KiB
Text
Error reporting
|
|
Function: comedi_errno -- number of last Comedilib error
|
|
Retval: int
|
|
Param: void
|
|
Description:
|
|
When a Comedilib function fails, it usually returns -1 or
|
|
NULL, depending on the return type. An internal library
|
|
variable stores an error number, which can be retrieved with
|
|
comedi_errno(). This error number can be converted to a
|
|
human-readable form by the functions
|
|
<link linkend="func-ref-comedi-perror"><function>comedi_perror</function></link>
|
|
and
|
|
<link linkend="func-ref-comedi-strerror"><function>comedi_strerror</function></link>
|
|
.
|
|
|
|
These functions are intended to mimic the behavior of the
|
|
standard C library functions perror(), strerror(), and errno.
|
|
In particular, Comedilib functions sometimes return an error
|
|
that is generated inside the C library; the comedi error
|
|
message in this case is the same as the C library.
|
|
|
|
The function comedi_errno() returns an integer describing
|
|
the most recent comedilib error. This integer may be used
|
|
as the errnum parameter for comedi_strerror().
|
|
|
|
Function: comedi_loglevel -- change Comedilib logging properties
|
|
Retval: int
|
|
Param: int loglevel
|
|
Description:
|
|
This function affects the output of debugging and error messages
|
|
from Comedilib. By increasing the loglevel, additional debugging
|
|
information will be printed. Error and debugging messages are
|
|
printed to the stream stderr.
|
|
|
|
The default loglevel can be set by using the environment variable
|
|
COMEDI_LOGLEVEL. The default loglevel is 1.
|
|
|
|
In order to conserve resources, some debugging information is
|
|
disabled by default when Comedilib is compiled.
|
|
|
|
The meaning of the loglevels is as follows:
|
|
<table frame="box" rules="all">
|
|
<tr>
|
|
<th>Loglevel</th>
|
|
<th>Behavior</th>
|
|
</tr>
|
|
<tr>
|
|
<td>0</td>
|
|
<td>Comedilib prints nothing.</td>
|
|
</tr>
|
|
<tr>
|
|
<td>1</td>
|
|
<td>
|
|
(default) Comedilib prints error messages when
|
|
there is a self-consistency error (i.e., an internal bug.)
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td>2</td>
|
|
<td>
|
|
Comedilib prints an error message when an invalid
|
|
parameter is passed.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td>3</td>
|
|
<td>
|
|
Comedilib prints an error message whenever an
|
|
error is generated in the Comedilib library or in the C library,
|
|
when called by Comedilib.
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td>4</td>
|
|
<td>Comedilib prints a lot of junk.</td>
|
|
</tr>
|
|
</table>
|
|
Returns:
|
|
This function returns the previous loglevel.
|
|
|
|
Function: comedi_perror -- print a Comedilib error message
|
|
Retval: void
|
|
Param: const char * s
|
|
Description:
|
|
When a Comedilib function fails, it usually returns -1 or
|
|
NULL, depending on the return type. An internal library
|
|
variable stores an error number, which can be retrieved with
|
|
<link linkend="func-ref-comedi-errno"><function>comedi_errno</function></link>
|
|
. This error number can be converted to a
|
|
human-readable form by the functions
|
|
comedi_perror() or
|
|
<link linkend="func-ref-comedi-strerror"><function>comedi_strerror</function></link>
|
|
.
|
|
|
|
These functions are intended to mimic the behavior of the
|
|
standard C library functions perror(), strerror(), and errno.
|
|
In particular, Comedilib functions sometimes return an error
|
|
that is generated inside the C library; the comedi error
|
|
message in this case is the same as the C library.
|
|
|
|
The function comedi_perror() prints an error message to stderr.
|
|
The error message consists of the argument string, a colon, a
|
|
space, a description of the error condition, and a new line.
|
|
|
|
Function: comedi_strerror -- return string describing Comedilib error code
|
|
Retval: const char *
|
|
Param: int errnum
|
|
Description:
|
|
When a Comedilib function fails, it usually returns -1 or
|
|
NULL, depending on the return type. An internal library
|
|
variable stores an error number, which can be retrieved with
|
|
comedi_errno(). This error number can be converted to a
|
|
human-readable form by the functions
|
|
<link linkend="func-ref-comedi-perror"><function>comedi_perror</function></link>
|
|
or comedi_strerror().
|
|
|
|
These functions are intended to mimic the behavior of the
|
|
standard C library functions perror(), strerror(), and errno.
|
|
In particular, Comedilib functions sometimes return an error
|
|
that is generated inside the C library; the comedi error
|
|
message in this case is the same as the C library.
|
|
|
|
The function comedi_strerror() returns a pointer to a
|
|
character string
|
|
describing the Comedilib error <parameter>errnum</parameter>.
|
|
The returned string may be
|
|
modified by a subsequent call to a strerr or perror function
|
|
(either the libc or Comedilib versions).
|
|
An unrecognized error number will
|
|
return a pointer to the string "undefined error", or similar.
|