unblock_dlg(1) [debian man page]

UNBLOCK_DLG(1)						      General Commands Manual						    UNBLOCK_DLG(1)

NAME

       unblock_dlg - Insert linefeeds into an optional-format Digital Line Graph (DLG) file

SYNOPSIS

       unblock_dlg [-L]

DESCRIPTION

       The  drawmap  program processes USGS optional-format Digital Line Graph (DLG) files (along with other types of files) to produce customized
       maps.  Drawmap is able to read these files in their native format.  However, since the files usually don't contain any linefeeds, they  are
       difficult  for a human to read.	Unblock_dlg filters a DLG file and inserts linefeeds for human readability.  It takes input from the stan-
       dard input and writes to the standard output.  The input data must be in uncompressed form, not in gzip-compressed form.  Also, unblock_dlg
       does not work with SDTS DLG files.

       Unblock_dlg normally takes no options, but, if you use the "-L" option, the program will print out some license information and exit.

       Some  DLG  files  already  have	embedded linefeeds.  Unblock_dlg makes a feeble attempt to detect these files and abort.  If the detection
       fails, the results are likely to be garbled, so it is wise to check the format of each file first.  The	drawmap  program,  with  the  "-i"
       option, will attempt to tell you whether a file contains linefeeds or not.

       The  intended  use  of  unblock_dlg is simply to let you conveniently examine the files to see what is in them.	However, if you are in the
       mood for adventure, or if you need to repair a defective file, you can use unblock_dlg to make the file easy to edit, then you can edit the
       file  as  desired.   Drawmap  can still process the files after linefeeds are inserted, but will become confused if any line (including the
       linefeed) is more than 80 characters long.  Drawmap may also become confused if you make any significant changes to the format of the file.

       You can use this capability to remove selected items from DLG files, when those items cause problems.  You  may	even  be  able	to  repair
       faulty  data.  However, you need to be familiar with the content and structure of DLG files in order to do this effectively.  You also need
       to remember that drawmap depends on DLG files having a predictable structure, and it won't properly parse  files  that  violate	this  pre-
       dictability.  Do this sort of thing only if you know what you are doing, or if you have a lot of free time on your hands.

       It should be noted that you can obtain a similar effect by using the command recommended by the USGS:

       dd if=inputfilename of=outputfilename ibs=8000 cbs=80 conv=unblock

       I  prefer  the  unblock_dlg  command because it simply replaces the last byte of each record with a linefeed.  This lets me easily tell how
       long the original records were.	The effect of unblock_dlg or dd can be undone by typing:

       dd if=inputfilename of=outputfilename ibs=8000 cbs=80 conv=block

       You may come across files that have a linefeed in the 81st byte.  Drawmap doesn't like these, both because it can't tell (within the  space
       of  the	first  80-byte	record) whether the file contains linefeeds or not, and because the records exceed the maximum record length of 80
       bytes.  You may be able to repair such files by blocking them with the above dd command.

SEE ALSO

       unblock_dem(1), drawmap(1)

								   Jul 24, 2001 						    UNBLOCK_DLG(1)

dlg(1)								PCCTS Manual Pages							    dlg(1)

NAME

       dlg - DFA Lexical Analyzer Generator

SYNTAX

       dlg [options] lexical_spec [output_file]

DESCRIPTION

       dlg is a tool that produces fast deterministic finite automata for recognizing regular expressions in input.

OPTIONS

       -CC    Generate C++ output.  The output_file is not specified in this case.

       -C[ level]
	      Where  level  is the compression level used.  0 indications no compression, 1 removes all unused characters from the transition from
	      table, and 2 maps equivalent characters into the same character classes.	It is suggested that level -C2 is used, since it will sig-
	      nificantly reduce the size of the dfa produced for lexical analyzer.

       -m     Produces the header file for the lexical mode with a name other than the default name of "mode.h".

       -i     An interactive, or as interactive as possible, parser is produced.  A character is only obtained when required to decide which state
	      to go to.  Some care must be taken to obtain accept states that do not require look ahead at the next character to determine if that
	      is  the  stop  state.   Any  regular  expression with a Kleene closure at the end is guaranteed to require another character of look
	      ahead.

       -cl class
	      Specify a class name for DLG to generate.  The default is DLGLexer.  "class" will be a subclass of DLGLexerBase; only used for -CC.

       -ci    The automaton will treat upper and lower case characters identically.  This is accomplished in the automaton; the characters in  the
	      lexical buffer are unmodified.

       -cs    Upper and lower case characters are treated as distinct.	This is the default.

       -o dir Directory  where	output	files  should go (default=".").  This is very nice for keeping the source directory clear of ANTLR and DLG
	      spawn.

       -Wambiguity
	      Warns if more than one regular expression could match the same character sequence.  The warnings give the numbers of the expressions
	      in the dlg lexical specification file.  The numbering of the expressions starts at one.  Multiple warnings may be print for the same
	      expressions.

       -      Used in place of file names to get input from standard in or send output to standard out.

SPECIAL CONSIDERATIONS

       Dlg works...  we think.	There is no implicit guarantee of anything.  We reserve no legal rights to the software known as the  Purdue  Com-
       piler  Construction Tool Set (PCCTS) -- PCCTS is in the public domain.  An individual or company may do whatever they wish with source code
       distributed with PCCTS or the code generated by PCCTS, including the incorporation of PCCTS, or its output, into commercial  software.	We
       encourage  users to develop software with PCCTS.  However, we do ask that credit is given to us for developing PCCTS.  By "credit", we mean
       that if you incorporate our source code into one of your programs (commercial product, research project, or otherwise) that you acknowledge
       this fact somewhere in the documentation, research report, etc...  If you like PCCTS and have developed a nice tool with the output, please
       mention that you developed it using PCCTS.  As long as these guidelines are followed, we expect	to  continue  enhancing  this  system  and
       expect to make other tools available as they are completed.

FILES

       mode.h , dlgauto.h , dlgdef.h

SEE ALSO

       antlr(1), pccts(1)

BUGS

DLG
								    April 1994								    dlg(1)