1COMEDI_ERRNO(3)                                                COMEDI_ERRNO(3)
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NAME

6       comedi_errno - number of last Comedilib error
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SYNOPSIS

9       #include <comedilib.h>
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11       int comedi_errno (void );
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DESCRIPTION

14       When a Comedilib function fails, it usually returns -1 or NULL, depend‐
15       ing on the return type.  An internal library variable stores  an  error
16       number,  which can be retrieved with comedi_errno().  This error number
17       can be converted to a human-readable form by the functions  comedi_per‐
18       ror() and comedi_strerror().
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20       These  functions  are  intended to mimic the behavior of the standard C
21       library functions perror(),  strerror(),  and  errno.   In  particular,
22       Comedilib  functions sometimes return an error that is generated inside
23       the C library; the comedi error message in this case is the same as the
24       C library.
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26       The  function  comedi_errno()  returns  an  integer describing the most
27       recent comedilib error.  This integer may be used as the errnum parame‐
28       ter for comedi_strerror().
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30       Note  that  comedi_errno()  is deliberately different than the variable
31       errno.  This is to overcome difficulties in making errno thread-safe.
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33                                28 October 2007                COMEDI_ERRNO(3)