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explain_putchar(3)	   Library Functions Manual	    explain_putchar(3)

NAME
       explain_putchar - explain putchar(3) errors

SYNOPSIS
       #include	<libexplain/putchar.h>
       const char *explain_putchar(int c);
       const char *explain_errno_putchar(int errnum, int c);
       void explain_message_putchar(char *message, int message_size, int c);
       void explain_message_errno_putchar(char *message, int message_size, int
       errnum, int c);

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

   explain_putchar
       const char *explain_putchar(int c);

       The explain_putchar function is used to obtain an explanation of	an er-
       ror returned by the putchar(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 fol-
       lowing example:
	      if (putchar(c) ==	EOF)
	      {
		  fprintf(stderr, "%s\n", explain_putchar(c));
		  exit(EXIT_FAILURE);
	      }

       c       The original c, exactly as  passed  to  the  putchar(3)	system
	       call.

       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,  in-
	       cluding other threads.

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

   explain_errno_putchar
       const char *explain_errno_putchar(int errnum, int c);

       The explain_errno_putchar function is used to obtain an explanation  of
       an error	returned by the	putchar(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 fol-
       lowing example:
	      if (putchar(c) ==	EOF)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_putchar(err, c));
		  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.

       c       The original c, exactly as  passed  to  the  putchar(3)	system
	       call.

       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,  in-
	       cluding other threads.

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

   explain_message_putchar
       void explain_message_putchar(char *message, int message_size, int c);

       The explain_message_putchar function may	be used	to  obtain an explana-
       tion of an error	returned by the	putchar(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  fol-
       lowing example:
	      if (putchar(c) ==	EOF)
	      {
		  char message[3000];
		  explain_message_putchar(message, sizeof(message), c);
		  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 re-
	       turned message.

       c       The original c, exactly as  passed  to  the  putchar(3)	system
	       call.

   explain_message_errno_putchar
       void explain_message_errno_putchar(char *message, int message_size, int
       errnum, int c);

       The explain_message_errno_putchar function may be used to obtain	an ex-
       planation  of  an  error	 returned  by the putchar(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  fol-
       lowing example:
	      if (putchar(c) ==	EOF)
	      {
		  int err = errno;
		  char message[3000];
		  explain_message_errno_putchar(message, sizeof(message), err, c);
		  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 re-
	       turned 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.

       c       The original c, exactly as  passed  to  the  putchar(3)	system
	       call.

SEE ALSO
       putchar(3)
	       output of characters

       explain_putchar_or_die(3)
	       output of characters and	report errors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2008 Peter	Miller

							    explain_putchar(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT

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