[h316.git] / pc-tools / ldc2 / doc / req_spec.tex

\section{Functional Specification}

%*******************************************************************************
\subsection{Data input processing}

\rd{inp001}{Data source select}{
	The tape data in Honeywell silent 4/6/6 code 
	\cite{ser16:progref:bformats} shall be read in from standard input or 
	from an input file.
}

%*******************************************************************************
\subsection{Data integrity checks}

The tape data shall be checked against the Honeywell tape block specification
found in \cite{ser16:progref:bformats}.
 
\rd{chk001}{Block integrity check}{
	Every data block's integrity shall be checked by the means of 
	detecting unexpected end of file while reading in the block.
}

\rd{chk002}{Block checksum check}{
	Every data block's checksum shall be calculated and checked according
	to \cite{ser16:progref:bformats}.
}

\rd{chk003}{Block type check}{
	Every data block contains its blocktype encoded in a specified location.
	It shall be checked that each data block's type field contains one of
	the type codes described in \cite{ser16:progref:bformats}.
}

\rd{chk004}{Object integrity check}{
	Every object on the tape (i.e. the output of one DAP-16 or FORTRAN IV 
	compiler run) consists of multiple data blocks.
	According to \cite{ser16:progref:bformats}, the last block of each
	object must be of one of the end block types.\\
	It shall be checked if the last data block read before end of input or 
	an end of tape mark is an appropriate end block.
}

\rd{chk005}{Interactive checksum error handling}{
	The program shall be configurable to pause block processing on
	detection of a checksum error (\req{chk002}) and resume processing after
	user intervention.\\
	This feature is incompatible with data input from standard input.
}

%*******************************************************************************
\subsection{Additional features}

\rd{h001}{Print help message}{
	A help message is output to standard error.
}

%*******************************************************************************
\newpage
\subsection{Data analysis}

\rd{da001}{List tape contents}{
	Output a list containing a human-readable fixed-format description
	of all blocks contained in the input data.\\
	The output line format shall be unified for all block types.
}

\rd{da002}{List exported symbols}{
	Output a list of all exported symbols.
}

\rd{da003}{List called symbols}{
	Output a list of all called symbols.
}

\rd{da004}{List unsatisfied dependencies}{
	Output a list of all unsatisfied dependencies i.e.
	all called symbols that appear in the output of \req{dp003} but
	not in the output of \req{dp002}.
}

\rd{da005}{Tape information output}{
	It shall be possible to output a line containing at least
	the following information about a tape image:
	\begin{itemize}
	\item Number of bytes read from data source
	\item Number of blocks read in
	\end{itemize}
}

\rd{da006}{Text output}{
	Text from \req{da001},\req{da002},\req{da003}, \req{da004},
	 and \req{da005} is output to standard output or to a file.
}

%*******************************************************************************
\newpage
\subsection{Data processing}

\rd{dp001}{Split into object files}{
	The tape data shall be divided into self-contained object files.\\
	The generated file names are derived from the first symbol name
	defined in the current object.\\
	Example: If an object exports the symbols SONNE, MOND
	and STERNE, the resulting file name will be SONNE.\\
	EOT (end of tape) blocks shall not be output in this mode of operation.
}

\rd{dp002}{Split into numbered object files}{
	Similar to \req{dp006}, but the object file names are prepended with
	a zero-padded three digit number and EOT blocks are not suppressed.
}

%*******************************************************************************	
\newpage
\subsection{Program configuration}

\rd{cfg001}{Configuration process}{
	The following sequence shall be used to acquire the working 
	configuration:
	\begin{enumerate}
		\item Configuration file according to environment variable:\\
			If the environment variable LDC\_CONFIG is set, that
			file shall be parsed.
		\item Configuration file according to command line parameter:\\
			If the command line parameter specifying a configuration
			file is found,
			the specified configuration file is parsed.\\
			Any values in this configuration file
			override values found in the previously read 
			configuration file. 
		\item Configuration parameters passed via the command line:\\
			Parameters passed on the command line will override
			values from previously read configuration files.
	\end{enumerate}
}

\rd{cfg002}{Parameter types}{
	The program shall accept two types of parameters:
	\begin{itemize}
	\item Switches:\\
		A switch is a binary value which can have the value true or 
		false.
	\item Strings:\\
		A string parameter is a parameter requiring a string value.\\
		A typical use would be a file name for input or output.
	\end{itemize}
}

\newpage
\rd{cfg003}{Switch parameters}{
	The following switch parameters shall be accepted:
	\begin{table}[H]\begin{center}
	\begin{tabular}{|r|p{2.5em}|p{23em}|}
	\hline
	\bf Long Form & \bf Short form & \bf Description\\
	\hline
 	help                       & h & Show help message (\req{h001})\\
	output\_info		   & a & Output data info (\req{da005})	.\\
	output\_called             & c & Output a list of called symbols 
						(\req{da003}).\\ 
	output\_exported           & e & Output a list of exported symbols 
						(\req{da002}).\\
	output\_unsatisfied        & u & Output a list of unsatisfied 
						dependencies (\req{da004}).\\
	split\_objects             & s & Split into object files 
						(\req{dp001}).\\
	split\_objects\_numbered   & S & Split into numbered object files 
						(\req{dp002}).\\
	ignore\_block\_errors      & b & Ignore block integrity errors 
						(\req{err001},\req{chk001}).\\
	ignore\_checksum\_errors   & k & Ignore Checksum errors 
						(\req{err001}\req{chk002}).\\
	pause\_on\_checksum\_error & p & Wait for user input on checksum error 
						(\req{chk005}).\\
	ignore\_unknown\_block\_errors    & n  & Ignore errors causes by 
						datablocks of 	unknown type
						 (\req{err001}\req{chk003}).\\
	ignore\_object\_integrity\_errors & g & Ignore errors caused by objects
						without proper end block 
						(\req{err001}\req{chk004}).\\
	\hline 
	\end{tabular}\end{center}
	\caption{Configuration switches}
	\end{table}	
}

\rd{cfg004}{String parameters}{
	The following string parameters shall be accepted:
	\begin{table}[H]\begin{center}
	\begin{tabular}{|r|p{2.5em}|l|}
	\hline
	\bf Long Form & \bf Short form & \bf Description\\
	\hline
	in\_file                   & i & Set input file (\req{inp001}). \\
	out\_file                  & o & Set output file for text output(\req{dp008}).\\
	\hline 
	\end{tabular}\end{center}
	\caption{Configuration strings}
	\end{table}	

}
\newpage
\rd{cfg005}{Configuration file syntax}{
	The configuration file must comply two the following grammar, given in EBNF:
}
	\begin{verbatim}
ConfigurationFile = { ConfigurationLine "<EOL>" } ;
ConfigurationLine = SwitchLine | StringLine | CommentLine ;
       SwitchLine = WSpace SwLong  WSpace "=" BoolValue ;
       StringLine = WSpace StrLong WSpace "=" String ;
      CommentLine = WSpace [ "#" String ] ;
           WSpace = { " " } ;
           SwLong = "output_info" | "ouput_called" | "output_exported"
                    | "output_unsatisfied" | "split_objects" [ _"numbered" ]
                    | "ignore_block_errors" | "ignore_checksum_errors
                    | "pause_on_checksum_error"
                    | "ignore_unknown_block_errors"
                    | "ignore_object_integrity" ;
          StrLong = "out_file" | "in_file" ;
        BoolValue = TrueStr | FalseStr ;
           String = { ? Every character except newline ?} ;
          TrueStr = "yes" | "1" | "true" ;
         FalseStr = | "no" | "0" | "false" ;
	\end{verbatim}

\rd{cfg006}{Command Line syntax}{
	The command line must comply to the following grammar, given in EBNF:	
}
\begin{verbatim}
CommandLine = ProgramName Arguments ;
ProgramName = String ;
  Arguments = { " " } { " " Argument } [ " " InfileName ] ;
   Argument = { Switch | Parameter } 
 InfileName = String ;
     Switch = ShortSwitch | LongSwitch ;
  Parameter = ShortParam | LongParam ;
     String = { ? Every character except newline ? } ;
ShortSwitch = "-" SwShort ;
 LongSwitch = "--" SwLong [ "=" BoolValue ] ;
 ShortParam = "-" StrShort String ;
  LongParam = "--" StrLong "=" String ;
    SwShort = "h" | "a" | "c" | "e" | "u" | "s" | "S"
              | "b" | "k" | "p" | "n" | "g" ;
     SwLong = "help"
              | "output_info" | "ouput_called" | "output_exported"
              | "output_unsatisfied" | "split_objects" [ _"numbered" ]
              | "ignore_block_errors" | "ignore_checksum_errors"
              | "pause_on_checksum_error"
              | "ignore_unknown_block_errors"
              | "ignore_object_integrity" ;
   StrShort = "o" ;
    StrLong = "out_file" ;
\end{verbatim}

\newpage
\rd{cfg007}{Configuration implications}{
	\begin{itemize}
	\item pause\_on\_checksum\_errors implies ignore\_checksum\_errors.
	\item pause\_on\_checksum\_errors is completely ignored when input 
	is read from standard input.
	\item output\_* inhibits tape information output (\req{da001}).
	\item help inhibits all other actions.
	\end{itemize}
}

\rd{cfg008}{Default behaviour}{
	\begin{itemize}
	\item Data is read from standard input.
	\item All error conditions result in immediate program termination
		and an error message.
	\item Tape information according to \req{da001} is output.
	\item Text is output to standard output.
	\end{itemize}
}

%*******************************************************************************
\newpage
\subsection{Error handling}


\newcommand{\esup}{
	This error shall lead to an error message and immediate program
	termination or a warning message and program continuation.
}

\newcommand{\enosup}{
	This error shall always lead to an error message and immediate
	program termination.
}

\rd{err001}{Error types}{
	The following distinguished error types shall exist:
	\begin{itemize}
	\item Input/output error:\\ 
		Error occuring during reading from the input file descriptor
		or during writing to an output file.\\
		\enosup
	\item Block integrity error:\\
		Caused by failed check according to \req{chk001}.\\
		\esup
	\item Checksum error:\\
		Caused by failed check according to \req{chk002}.\\
		\esup
	\item Unknown block type error:\\
		Caused by failed check according to \req{chk003}.\\
		\esup		
	\item Object integrity error:\\
		Caused by failed check according to \req{chk004}.\\
		\esup
	\item Usage error:\\
		Error caused by errors in the program configuration i.e. wrong 
		parameters or impossible combinations of parameters.\\
		\enosup \\
		Additionally, the help (\req{h001}) message is output.
	\item	Internal program error:\\
		Error caused by internal program problems.\\
		This error should never occur.\\
		\enosup
	\end{itemize}
}

\rd{err002}{Program exit codes}{
	\begin{table}[H]
	\begin{center}
	\begin{tabular}{|r|c|}
		\hline
		\multicolumn{1}{|c|}{\bf Exit condition} & \bf Return code\\
		\hline
		Successfull program completion & 0 \\
		File open error & 1\\
		Input/output error & 2\\
		Block integrity error & 3\\
		Checksum error & 4\\
		Unknown block type error & 5\\
		Object integrity error & 6\\
		Usage error & 7\\
		Internal program error & 100 \\
		\hline 
	\end{tabular}
	\caption[Program Exit codes]{Exit codes}
	\end{center}
	\end{table}
}

\rd{err003}{Error and warning messages}{
	Error messages shall consinst of ''Error:'' and the error reason.\\
	Warning messages shall consist of ''Warning:'' and a descriptive 
	text.\\
	The following texts shall be used to form error and warning messages:
	\begin{table}[H]
	\begin{center}
	\begin{tabular}{|l|l|}
	\hline
	\bf Error condition & \bf Descriptive text\\ \hline
	File open error & Could not open $<$filename$>$ for reading/writing!\\
	Input error     &     Could not read from $<$filename$>$!\\
	Output error    &    Could not write to $<$filename$>$!\\
	Block integrity error & Block integrity check failed!\\
	Checksum error        & Block checksum wrong!\\
	Unknown block type    & Unknown block type!\\
	Object integrity      & Object integrity check failed!\\
	Usage error           & $<$Specific message describing the problem$>$\\
	\hline
	\end{tabular}
	\end{center}
	\caption[Program Exit codes]{Exit codes}
	\end{table}
}

\rd{err004}{Error message output}{
	Any error messages shall be output to standard error.\\
	There shall be no way to suppress error messages.
}

\rd{err005}{Warning message output}{
	Any warning messages shall be output to standard error.\\
	There shall be a possibility to suppress warning messages.
}
Commit	Line	Data
ad324d29	1	\section{Functional Specification}
290011d2	2
	3	%*******************************************************************************
	4	\subsection{Data input processing}
	5
	6	\rd{inp001}{Data source select}{
	7	The tape data in Honeywell silent 4/6/6 code
	8	\cite{ser16:progref:bformats} shall be read in from standard input or
	9	from an input file.
	10	}
	11
	12	%*******************************************************************************
	13	\subsection{Data integrity checks}
	14
	15	The tape data shall be checked against the Honeywell tape block specification
	16	found in \cite{ser16:progref:bformats}.
	17
ad324d29	18	\rd{chk001}{Block integrity check}{
ad324d29	19	Every data block's integrity shall be checked by the means of
290011d2	20	detecting unexpected end of file while reading in the block.
	21	}
	22
	23	\rd{chk002}{Block checksum check}{
	24	Every data block's checksum shall be calculated and checked according
	25	to \cite{ser16:progref:bformats}.
	26	}
	27
	28	\rd{chk003}{Block type check}{
	29	Every data block contains its blocktype encoded in a specified location.
	30	It shall be checked that each data block's type field contains one of
	31	the type codes described in \cite{ser16:progref:bformats}.
	32	}
	33
	34	\rd{chk004}{Object integrity check}{
	35	Every object on the tape (i.e. the output of one DAP-16 or FORTRAN IV
	36	compiler run) consists of multiple data blocks.
	37	According to \cite{ser16:progref:bformats}, the last block of each
	38	object must be of one of the end block types.\\
	39	It shall be checked if the last data block read before end of input or
	40	an end of tape mark is an appropriate end block.
	41	}
	42
	43	\rd{chk005}{Interactive checksum error handling}{
	44	The program shall be configurable to pause block processing on
	45	detection of a checksum error (\req{chk002}) and resume processing after
	46	user intervention.\\
	47	This feature is incompatible with data input from standard input.
	48	}
	49
	50	%*******************************************************************************
ad324d29	51	\subsection{Additional features}
	52
	53	\rd{h001}{Print help message}{
	54	A help message is output to standard error.
	55	}
	56
	57	%*******************************************************************************
	58	\newpage
290011d2	59	\subsection{Data analysis}
	60
	61	\rd{da001}{List tape contents}{
	62	Output a list containing a human-readable fixed-format description
	63	of all blocks contained in the input data.\\
	64	The output line format shall be unified for all block types.
	65	}
	66
	67	\rd{da002}{List exported symbols}{
	68	Output a list of all exported symbols.
	69	}
	70
	71	\rd{da003}{List called symbols}{
	72	Output a list of all called symbols.
	73	}
	74
	75	\rd{da004}{List unsatisfied dependencies}{
	76	Output a list of all unsatisfied dependencies i.e.
	77	all called symbols that appear in the output of \req{dp003} but
	78	not in the output of \req{dp002}.
	79	}
	80
	81	\rd{da005}{Tape information output}{
	82	It shall be possible to output a line containing at least
	83	the following information about a tape image:
	84	\begin{itemize}
	85	\item Number of bytes read from data source
	86	\item Number of blocks read in
	87	\end{itemize}
	88	}
	89
	90	\rd{da006}{Text output}{
	91	Text from \req{da001},\req{da002},\req{da003}, \req{da004},
	92	and \req{da005} is output to standard output or to a file.
	93	}
	94
	95	%*******************************************************************************
ad324d29	96	\newpage
290011d2	97	\subsection{Data processing}
	98
	99	\rd{dp001}{Split into object files}{
	100	The tape data shall be divided into self-contained object files.\\
	101	The generated file names are derived from the first symbol name
	102	defined in the current object.\\
	103	Example: If an object exports the symbols SONNE, MOND
	104	and STERNE, the resulting file name will be SONNE.\\
	105	EOT (end of tape) blocks shall not be output in this mode of operation.
	106	}
	107
	108	\rd{dp002}{Split into numbered object files}{
	109	Similar to \req{dp006}, but the object file names are prepended with
	110	a zero-padded three digit number and EOT blocks are not suppressed.
	111	}
	112
290011d2	113	%*******************************************************************************
ad324d29	114	\newpage
290011d2	115	\subsection{Program configuration}
	116
	117	\rd{cfg001}{Configuration process}{
ad324d29	118	The following sequence shall be used to acquire the working
ad324d29	119	configuration:
290011d2	120	\begin{enumerate}
	121	\item Configuration file according to environment variable:\\
	122	If the environment variable LDC\_CONFIG is set, that
	123	file shall be parsed.
	124	\item Configuration file according to command line parameter:\\
	125	If the command line parameter specifying a configuration
	126	file is found,
	127	the specified configuration file is parsed.\\
	128	Any values in this configuration file
ad324d29	129	override values found in the previously read
ad324d29	130	configuration file.
290011d2	131	\item Configuration parameters passed via the command line:\\
	132	Parameters passed on the command line will override
	133	values from previously read configuration files.
	134	\end{enumerate}
	135	}
	136
	137	\rd{cfg002}{Parameter types}{
	138	The program shall accept two types of parameters:
	139	\begin{itemize}
	140	\item Switches:\\
ad324d29	141	A switch is a binary value which can have the value true or
ad324d29	142	false.
290011d2	143	\item Strings:\\
	144	A string parameter is a parameter requiring a string value.\\
	145	A typical use would be a file name for input or output.
	146	\end{itemize}
	147	}
	148
ad324d29	149	\newpage
290011d2	150	\rd{cfg003}{Switch parameters}{
	151	The following switch parameters shall be accepted:
	152	\begin{table}[H]\begin{center}
ad324d29	153	\begin{tabular}{\|r\|p{2.5em}\|p{23em}\|}
290011d2	154	\hline
	155	\bf Long Form & \bf Short form & \bf Description\\
	156	\hline
	157	help & h & Show help message (\req{h001})\\
ad324d29	158	output\_info & a & Output data info (\req{da005}) .\\
	159	output\_called & c & Output a list of called symbols
	160	(\req{da003}).\\
	161	output\_exported & e & Output a list of exported symbols
	162	(\req{da002}).\\
	163	output\_unsatisfied & u & Output a list of unsatisfied
	164	dependencies (\req{da004}).\\
	165	split\_objects & s & Split into object files
	166	(\req{dp001}).\\
	167	split\_objects\_numbered & S & Split into numbered object files
	168	(\req{dp002}).\\
	169	ignore\_block\_errors & b & Ignore block integrity errors
	170	(\req{err001},\req{chk001}).\\
	171	ignore\_checksum\_errors & k & Ignore Checksum errors
	172	(\req{err001}\req{chk002}).\\
	173	pause\_on\_checksum\_error & p & Wait for user input on checksum error
	174	(\req{chk005}).\\
	175	ignore\_unknown\_block\_errors & n & Ignore errors causes by
	176	datablocks of unknown type
	177	(\req{err001}\req{chk003}).\\
	178	ignore\_object\_integrity\_errors & g & Ignore errors caused by objects
	179	without proper end block
	180	(\req{err001}\req{chk004}).\\
290011d2	181	\hline
	182	\end{tabular}\end{center}
	183	\caption{Configuration switches}
	184	\end{table}
	185	}
	186
	187	\rd{cfg004}{String parameters}{
	188	The following string parameters shall be accepted:
	189	\begin{table}[H]\begin{center}
	190	\begin{tabular}{\|r\|p{2.5em}\|l\|}
	191	\hline
	192	\bf Long Form & \bf Short form & \bf Description\\
	193	\hline
ad324d29	194	in\_file & i & Set input file (\req{inp001}). \\
ad324d29	195	out\_file & o & Set output file for text output(\req{dp008}).\\
290011d2	196	\hline
	197	\end{tabular}\end{center}
	198	\caption{Configuration strings}
	199	\end{table}
	200
	201	}
ad324d29	202	\newpage
290011d2	203	\rd{cfg005}{Configuration file syntax}{
	204	The configuration file must comply two the following grammar, given in EBNF:
	205	}
	206	\begin{verbatim}
	207	ConfigurationFile = { ConfigurationLine "<EOL>" } ;
	208	ConfigurationLine = SwitchLine \| StringLine \| CommentLine ;
	209	SwitchLine = WSpace SwLong WSpace "=" BoolValue ;
	210	StringLine = WSpace StrLong WSpace "=" String ;
	211	CommentLine = WSpace [ "#" String ] ;
	212	WSpace = { " " } ;
	213	SwLong = "output_info" \| "ouput_called" \| "output_exported"
	214	\| "output_unsatisfied" \| "split_objects" [ _"numbered" ]
	215	\| "ignore_block_errors" \| "ignore_checksum_errors
	216	\| "pause_on_checksum_error"
	217	\| "ignore_unknown_block_errors"
	218	\| "ignore_object_integrity" ;
	219	StrLong = "out_file" \| "in_file" ;
	220	BoolValue = TrueStr \| FalseStr ;
	221	String = { ? Every character except newline ?} ;
	222	TrueStr = "yes" \| "1" \| "true" ;
	223	FalseStr = \| "no" \| "0" \| "false" ;
ad324d29	224	\end{verbatim}
290011d2	225
ad324d29	226	\rd{cfg006}{Command Line syntax}{
290011d2	227	The command line must comply to the following grammar, given in EBNF:
	228	}
	229	\begin{verbatim}
	230	CommandLine = ProgramName Arguments ;
	231	ProgramName = String ;
	232	Arguments = { " " } { " " Argument } [ " " InfileName ] ;
	233	Argument = { Switch \| Parameter }
	234	InfileName = String ;
	235	Switch = ShortSwitch \| LongSwitch ;
	236	Parameter = ShortParam \| LongParam ;
	237	String = { ? Every character except newline ? } ;
	238	ShortSwitch = "-" SwShort ;
	239	LongSwitch = "--" SwLong [ "=" BoolValue ] ;
	240	ShortParam = "-" StrShort String ;
	241	LongParam = "--" StrLong "=" String ;
ad324d29	242	SwShort = "h" \| "a" \| "c" \| "e" \| "u" \| "s" \| "S"
290011d2	243	\| "b" \| "k" \| "p" \| "n" \| "g" ;
ad324d29	244	SwLong = "help"
ad324d29	245	\| "output_info" \| "ouput_called" \| "output_exported"
290011d2	246	\| "output_unsatisfied" \| "split_objects" [ _"numbered" ]
ad324d29	247	\| "ignore_block_errors" \| "ignore_checksum_errors"
290011d2	248	\| "pause_on_checksum_error"
	249	\| "ignore_unknown_block_errors"
	250	\| "ignore_object_integrity" ;
ad324d29	251	StrShort = "o" ;
290011d2	252	StrLong = "out_file" ;
	253	\end{verbatim}
	254
ad324d29	255	\newpage
290011d2	256	\rd{cfg007}{Configuration implications}{
	257	\begin{itemize}
	258	\item pause\_on\_checksum\_errors implies ignore\_checksum\_errors.
	259	\item pause\_on\_checksum\_errors is completely ignored when input
	260	is read from standard input.
	261	\item output\_* inhibits tape information output (\req{da001}).
	262	\item help inhibits all other actions.
	263	\end{itemize}
	264	}
	265
	266	\rd{cfg008}{Default behaviour}{
	267	\begin{itemize}
	268	\item Data is read from standard input.
	269	\item All error conditions result in immediate program termination
	270	and an error message.
	271	\item Tape information according to \req{da001} is output.
	272	\item Text is output to standard output.
	273	\end{itemize}
	274	}
	275
	276	%*******************************************************************************
ad324d29	277	\newpage
290011d2	278	\subsection{Error handling}
	279
	280
	281	\newcommand{\esup}{
	282	This error shall lead to an error message and immediate program
	283	termination or a warning message and program continuation.
	284	}
	285
	286	\newcommand{\enosup}{
	287	This error shall always lead to an error message and immediate
	288	program termination.
	289	}
	290
	291	\rd{err001}{Error types}{
	292	The following distinguished error types shall exist:
	293	\begin{itemize}
	294	\item Input/output error:\\
	295	Error occuring during reading from the input file descriptor
	296	or during writing to an output file.\\
	297	\enosup
	298	\item Block integrity error:\\
	299	Caused by failed check according to \req{chk001}.\\
	300	\esup
	301	\item Checksum error:\\
	302	Caused by failed check according to \req{chk002}.\\
	303	\esup
	304	\item Unknown block type error:\\
	305	Caused by failed check according to \req{chk003}.\\
	306	\esup
	307	\item Object integrity error:\\
	308	Caused by failed check according to \req{chk004}.\\
	309	\esup
	310	\item Usage error:\\
ad324d29	311	Error caused by errors in the program configuration i.e. wrong
290011d2	312	parameters or impossible combinations of parameters.\\
	313	\enosup \\
	314	Additionally, the help (\req{h001}) message is output.
	315	\item Internal program error:\\
	316	Error caused by internal program problems.\\
	317	This error should never occur.\\
	318	\enosup
	319	\end{itemize}
	320	}
	321
	322	\rd{err002}{Program exit codes}{
	323	\begin{table}[H]
	324	\begin{center}
	325	\begin{tabular}{\|r\|c\|}
	326	\hline
	327	\multicolumn{1}{\|c\|}{\bf Exit condition} & \bf Return code\\
	328	\hline
	329	Successfull program completion & 0 \\
	330	File open error & 1\\
	331	Input/output error & 2\\
	332	Block integrity error & 3\\
	333	Checksum error & 4\\
	334	Unknown block type error & 5\\
	335	Object integrity error & 6\\
	336	Usage error & 7\\
	337	Internal program error & 100 \\
	338	\hline
	339	\end{tabular}
	340	\caption[Program Exit codes]{Exit codes}
	341	\end{center}
	342	\end{table}
	343	}
	344
	345	\rd{err003}{Error and warning messages}{
	346	Error messages shall consinst of ''Error:'' and the error reason.\\
	347	Warning messages shall consist of ''Warning:'' and a descriptive
	348	text.\\
	349	The following texts shall be used to form error and warning messages:
	350	\begin{table}[H]
	351	\begin{center}
	352	\begin{tabular}{\|l\|l\|}
	353	\hline
	354	\bf Error condition & \bf Descriptive text\\ \hline
	355	File open error & Could not open $<$filename$>$ for reading/writing!\\
	356	Input error & Could not read from $<$filename$>$!\\
	357	Output error & Could not write to $<$filename$>$!\\
	358	Block integrity error & Block integrity check failed!\\
	359	Checksum error & Block checksum wrong!\\
	360	Unknown block type & Unknown block type!\\
	361	Object integrity & Object integrity check failed!\\
ad324d29	362	Usage error & $<$Specific message describing the problem$>$\\
290011d2	363	\hline
	364	\end{tabular}
	365	\end{center}
	366	\caption[Program Exit codes]{Exit codes}
	367	\end{table}
	368	}
	369
	370	\rd{err004}{Error message output}{
	371	Any error messages shall be output to standard error.\\
	372	There shall be no way to suppress error messages.
	373	}
	374
	375	\rd{err005}{Warning message output}{
	376	Any warning messages shall be output to standard error.\\
	377	There shall be a possibility to suppress warning messages.
	378	}
	379