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NAME

       explain_getchar - explain getchar(3) errors

SYNOPSIS

       #include <libexplain/getchar.h>
       const char *explain_getchar(void);
       const char *explain_errno_getchar(int errnum, void);
       void explain_message_getchar(char *message, int message_size);
       void explain_message_errno_getchar(char *message, int message_size, int
       errnum);

DESCRIPTION

       These functions may be used to obtain explanations for errors  returned
       by the getchar(3) system call.

   explain_getchar
       const char *explain_getchar(void);

       The  explain_getchar  function  is  used to obtain an explanation of an
       error returned by the getchar(3) system call.  The  least  the  message
       will  contain  is  the value of strerror(errno), but usually it will do
       much better, and indicate the underlying cause in more detail.

       The errno global variable will be used to obtain the error value to  be
       decoded.

       This  function  is  intended  to  be  used  in a fashion similar to the
       following example:
              int c = getchar();
              if (c == EOF && ferror(stdin))
              {
                  fprintf(stderr, "%s\n", explain_getchar());
                  exit(EXIT_FAILURE);
              }

       Returns:
               The message explaining  the  error.   This  message  buffer  is
               shared by all libexplain functions which do not supply a buffer
               in their argument list.  This will be overwritten by  the  next
               call  to  any  libexplain  function  which  shares this buffer,
               including other threads.

       Note: This function is not thread safe,  because  it  shares  a  return
       buffer across all threads, and many other functions in this library.

   explain_errno_getchar
       const char *explain_errno_getchar(int errnum);

       The  explain_errno_getchar function is used to obtain an explanation of
       an error returned by the getchar(3) system call.  The least the message
       will  contain  is the value of strerror(errnum), but usually it will do
       much better, and indicate the underlying cause in more detail.

       This function is intended to be  used  in  a  fashion  similar  to  the
       following example:
              int c = getchar();
              if (c == EOF && ferror(stdin))
              {
                  int err = errno;
                  fprintf(stderr, "%s\n", explain_errno_getchar(err, ));
                  exit(EXIT_FAILURE);
              }

       errnum  The  error value to be decoded, usually obtained from the errno
               global variable just before this function is called.   This  is
               necessary  if you need to call any code between the system call
               to be explained and this function, because many libc  functions
               will alter the value of errno.

       Returns:
               The  message  explaining  the  error.   This  message buffer is
               shared by all libexplain functions which do not supply a buffer
               in  their  argument list.  This will be overwritten by the next
               call to any  libexplain  function  which  shares  this  buffer,
               including other threads.

       Note:  This  function  is  not  thread safe, because it shares a return
       buffer across all threads, and many other functions in this library.

   explain_message_getchar
       void explain_message_getchar(char *message, int message_size);

       The  explain_message_getchar  function  may  be  used  to   obtain   an
       explanation  of  an  error returned by the getchar(3) system call.  The
       least the message will contain is the  value  of  strerror(errno),  but
       usually  it  will  do much better, and indicate the underlying cause in
       more detail.

       The errno global variable will be used to obtain the error value to  be
       decoded.

       This  function  is  intended  to  be  used  in a fashion similar to the
       following example:
              int c = getchar();
              if (c == EOF && ferror(stdin))
              {
                  char message[3000];
                  explain_message_getchar(message, sizeof(message), );
                  fprintf(stderr, "%s\n", message);
                  exit(EXIT_FAILURE);
              }

       message The location in which to store  the  returned  message.   If  a
               suitable  message  return  buffer is supplied, this function is
               thread safe.

       message_size
               The size in bytes  of  the  location  in  which  to  store  the
               returned message.

   explain_message_errno_getchar
       void explain_message_errno_getchar(char *message, int message_size, int
       errnum);

       The explain_message_errno_getchar function may be  used  to  obtain  an
       explanation  of  an  error returned by the getchar(3) system call.  The
       least the message will contain is the value  of  strerror(errnum),  but
       usually  it  will  do much better, and indicate the underlying cause in
       more detail.

       This function is intended to be  used  in  a  fashion  similar  to  the
       following example:
              int c = getchar();
              if (c == EOF && ferror(stdin))
              {
                  int err = errno;
                  char message[3000];
                  explain_message_errno_getchar(message, sizeof(message), err, );
                  fprintf(stderr, "%s\n", message);
                  exit(EXIT_FAILURE);
              }

       message The  location  in  which  to  store the returned message.  If a
               suitable message return buffer is supplied,  this  function  is
               thread safe.

       message_size
               The  size  in  bytes  of  the  location  in  which to store the
               returned message.

       errnum  The error value to be decoded, usually obtained from the  errno
               global  variable  just before this function is called.  This is
               necessary if you need to call any code between the system  call
               to  be explained and this function, because many libc functions
               will alter the value of errno.

SEE ALSO

       getchar(3)
               input of characters

       explain_getchar_or_die(3)
               input of characters and report errors

COPYRIGHT

       libexplain version 0.19
       Copyright (C) 2008 Peter Miller

                                                            explain_getchar(3)