ERROR(1)						    BSD General Commands Manual 						  ERROR(1)

NAME

     error -- analyze and disperse compiler error messages

SYNOPSIS

     error [-n] [-s] [-q] [-v] [-t suffix_list] [-I ignore_file] [name]

DESCRIPTION

     error analyzes and optionally disperses the diagnostic error messages produced by a number of compilers and language processors to the source
     file and line where the errors occurred.  It can replace the painful, traditional methods of scribbling abbreviations of errors on paper, and
     permits error messages and source code to be viewed simultaneously without machinations of multiple windows in a screen editor.

     Options are:

     -I ignore_file
	     List of functions to ignore.  See nullify, below.

     -n      Do not touch any files; all error messages are sent to the standard output.

     -q      The user is queried whether s/he wants to touch the file.	A ``y'' or ``n'' to the question is necessary to continue.  Absence of the
	     -q option implies that all referenced files (except those referring to discarded error messages) are to be touched.

     -s      Print out statistics regarding the error categorization.  Not too useful.

     -t suffix_list
	     Take the following argument as a suffix list.  Files whose suffixes do not appear in the suffix list are not touched.  The suffix
	     list is dot separated, and ``*'' wildcards work.  Thus the suffix list:

		   .c.y.foo*.h

	     allows error to touch files ending with ``.c'', ``.y'', ``.foo*'' and ``.h''.

     -v      After all files have been touched, overlay the visual editor vi(1) with it set up to edit all files touched, and positioned in the
	     first touched file at the first error.  If vi(1) can't be found, try ex(1) or ed(1) from standard places.

     error looks at the error messages, either from the specified file name or from the standard input, and attempts to determine which language
     processor produced each error message, determines the source file and line number to which the error message refers, determines if the error
     message is to be ignored or not, and inserts the (possibly slightly modified) error message into the source file as a comment on the line
     preceding to which the line the error message refers.  Error messages which can't be categorized by language processor or content are not
     inserted into any file, but are sent to the standard output.  error touches source files only after all input has been read.

     error is intended to be run with its standard input connected via a pipe to the error message source.  Some language processors put error
     messages on their standard error file; others put their messages on the standard output.  Hence, both error sources should be piped together
     into error.  For example, when using the csh(1) syntax,

	   make -s lint | error -q -v

     will analyze all the error messages produced by whatever programs make(1) runs when making lint.

     error knows about the error messages produced by: make(1), cc(1), cpp(1), ccom(1), as(1), ld(1), lint(1), pi(1), pc(1), f77(1), and DEC
     Western Research Modula-2.  error knows a standard format for error messages produced by the language processors, so is sensitive to changes
     in these formats.	For all languages except Pascal, error messages are restricted to be on one line.  Some error messages refer to more than
     one line in more than one files; error will duplicate the error message and insert it at all of the places referenced.

     error will do one of six things with error messages.

     synchronize  Some language processors produce short errors describing which file it is processing.  error uses these to determine the file
		  name for languages that don't include the file name in each error message.  These synchronization messages are consumed entirely
		  by error.

     discard	  Error messages from lint(1) that refer to one of the two lint(1) libraries, /usr/libdata/lint/llib-lc and
		  /usr/libdata/lint/llib-port are discarded, to prevent accidently touching these libraries.  Again, these error messages are con-
		  sumed entirely by error.

     nullify	  Error messages from lint(1) can be nullified if they refer to a specific function, which is known to generate diagnostics which
		  are not interesting.	Nullified error messages are not inserted into the source file, but are written to the standard output.
		  The names of functions to ignore are taken from either the file named .errorrc in the user's home directory, or from the file
		  named by the -I option.  If the file does not exist, no error messages are nullified.  If the file does exist, there must be one
		  function name per line.

     not file specific
		  Error messages that can't be intuited are grouped together, and written to the standard output before any files are touched.
		  They will not be inserted into any source file.

     file specific
		  Error message that refer to a specific file, but to no specific line, are written to the standard output when that file is
		  touched.

     true errors  Error messages that can be intuited are candidates for insertion into the file to which they refer.

     Only true error messages are candidates for inserting into the file they refer to.  Other error messages are consumed entirely by error or
     are written to the standard output.  error inserts the error messages into the source file on the line preceding the line the language pro-
     cessor found in error.

     Each error message is turned into a one line comment for the language, and is internally flagged with the string ``###'' at the beginning of
     the error, and ``%%%'' at the end of the error.  This makes pattern searching for errors easier with an editor, and allows the messages to be
     easily removed.  In addition, each error message contains the source line number for the line the message refers to.

     A reasonably formatted source program can be recompiled with the error messages still in it, without having the error messages themselves
     cause future errors.  For poorly formatted source programs in free format languages, such as C or Pascal, it is possible to insert a comment
     into another comment, which can wreak havoc with a future compilation.  To avoid this, programs with comments and source on the same line
     should be formatted so that language statements appear before comments.

     error catches interrupt and terminate signals, and if in the insertion phase, will orderly terminate what it is doing.

SEE ALSO

     as(1), cc(1), ccom(1), cpp(1), lint(1), make(1)

FILES

     ~/.errorrc  function names to ignore for lint(1) error messages
     /dev/tty	 user's teletype

HISTORY

     The error command appeared in 4.0BSD.

AUTHOR

     Robert Henry

BUGS

     Opens the teletype directly to do user querying.

     Source files with links make a new copy of the file with only one link to it.

     Changing a language processor's format of error messages may cause error to not understand the error message.

     error, since it is purely mechanical, will not filter out subsequent errors caused by `floodgating' initiated by one syntactically trivial
     error.  Humans are still much better at discarding these related errors.

     Pascal error messages belong after the lines affected (error puts them before).  The alignment of the `' marking the point of error is also
     disturbed by error.

     error was designed for work on CRT's at reasonably high speed.  It is less pleasant on slow speed terminals, and has never been used on hard-
     copy terminals.

4th Berkeley Distribution					   June 6, 1993 					 4th Berkeley Distribution