dlg(1) [redhat man page]
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. -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)
Check Out this Related Man Page
GREP(1) General Commands Manual GREP(1) NAME
grep, egrep, fgrep - search a file for a pattern SYNOPSIS
grep [ option ] ... expression [ file ] ... egrep [ option ] ... [ expression ] [ file ] ... fgrep [ option ] ... [ strings ] [ file ] DESCRIPTION
Commands of the grep family search the input files (standard input default) for lines matching a pattern. Normally, each line found is copied to the standard output; unless the -h flag is used, the file name is shown if there is more than one input file. Grep patterns are limited regular expressions in the style of ed(1); it uses a compact nondeterministic algorithm. Egrep patterns are full regular expressions; it uses a fast deterministic algorithm that sometimes needs exponential space. Fgrep patterns are fixed strings; it is fast and compact. The following options are recognized. -v All lines but those matching are printed. -c Only a count of matching lines is printed. -l The names of files with matching lines are listed (once) separated by newlines. -n Each line is preceded by its line number in the file. -b Each line is preceded by the block number on which it was found. This is sometimes useful in locating disk block numbers by con- text. -s No output is produced, only status. -h Do not print filename headers with output lines. -y Lower case letters in the pattern will also match upper case letters in the input (grep only). -e expression Same as a simple expression argument, but useful when the expression begins with a -. -f file The regular expression (egrep) or string list (fgrep) is taken from the file. -x (Exact) only lines matched in their entirety are printed (fgrep only). Care should be taken when using the characters $ * [ ^ | ? ' " ( ) and in the expression as they are also meaningful to the Shell. It is safest to enclose the entire expression argument in single quotes ' '. Fgrep searches for lines that contain one of the (newline-separated) strings. Egrep accepts extended regular expressions. In the following description `character' excludes newline: A followed by a single character matches that character. The character ^ ($) matches the beginning (end) of a line. A . matches any character. A single character not otherwise endowed with special meaning matches that character. A string enclosed in brackets [] matches any single character from the string. Ranges of ASCII character codes may be abbreviated as in `a-z0-9'. A ] may occur only as the first character of the string. A literal - must be placed where it can't be mistaken as a range indicator. A regular expression followed by * (+, ?) matches a sequence of 0 or more (1 or more, 0 or 1) matches of the regular expression. Two regular expressions concatenated match a match of the first followed by a match of the second. Two regular expressions separated by | or newline match either a match for the first or a match for the second. A regular expression enclosed in parentheses matches a match for the regular expression. The order of precedence of operators at the same parenthesis level is [] then *+? then concatenation then | and newline. SEE ALSO
ed(1), sed(1), sh(1) DIAGNOSTICS
Exit status is 0 if any matches are found, 1 if none, 2 for syntax errors or inaccessible files. BUGS
Ideally there should be only one grep, but we don't know a single algorithm that spans a wide enough range of space-time tradeoffs. Lines are limited to 256 characters; longer lines are truncated. GREP(1)