Pattern matching with regular expressions. More...

#include <vul_reg_exp.h>

Public Member Functions
	vul_reg_exp ()
	Creates an empty regular expression.
	vul_reg_exp (char const *s)
	Creates a regular expression from string s, and compiles s.
	vul_reg_exp (vul_reg_exp const &)
	Copy constructor.
	~vul_reg_exp ()
	Frees space allocated for regular expression.
void	compile (char const *)
	Compiles char* --> regexp.
bool	find (char const *)
	true if regexp in char* arg.
bool	find (vcl_string const &)
	true if regexp in char* arg.
vcl_ptrdiff_t	start () const
	Returns the start index of the last item found.
vcl_ptrdiff_t	end () const
	Returns the end index of the last item found.
bool	operator== (vul_reg_exp const &) const
	Equality operator.
bool	operator!= (vul_reg_exp const &r) const
	Inequality operator.
bool	deep_equal (vul_reg_exp const &) const
	Same regexp and state?.
bool	is_valid () const
	Returns true if a valid RE is compiled and ready for pattern matching.
void	set_invalid ()
	Invalidates regular expression.
vcl_ptrdiff_t	start (long n) const
	Return start index of nth submatch.
vcl_ptrdiff_t	end (long n) const
	Return end index of nth submatch.
vcl_string	match (int n) const
	Return nth submatch as a string.
Static Public Member Functions
static const char *	protect (char c)
	Return an expression that will match precisely c.
Private Member Functions
void	clear_bufs ()
	private function to clear startp[] and endp[].
Private Attributes
const char *	startp [vul_reg_exp_nsubexp]
	anchor point of start position for n-th matching regular expression.
const char *	endp [vul_reg_exp_nsubexp]
	anchor point of end position for n-th matching regular expression.
char	regstart
	Internal use only.
char	reganch
	Internal use only.
const char *	regmust
	Internal use only.
int	regmlen
	Internal use only.
char *	program
int	progsize
const char *	searchstring

Detailed Description

Pattern matching with regular expressions.

A regular expression allows a programmer to specify complex patterns that can be searched for and matched against the character string of a string object. In its simplest form, a regular expression is a sequence of characters used to search for exact character matches. However, many times the exact sequence to be found is not known, or only a match at the beginning or end of a string is desired. This regular expression class implements regular expression pattern matching as is found and implemented in many UNIX commands and utilities.

Example: The perl code

     $filename =~ m"([a-z]+)\.cc";
     print $1;

is written as follows in C++

     vul_reg_exp re("([a-z]+)\\.cc");
     re.find(filename);
     vcl_cout << re.match(1);

The regular expression class provides a convenient mechanism for specifying and manipulating regular expressions. The regular expression object allows specification of such patterns by using the following regular expression metacharacters:

^ Matches at beginning of a line
$ Matches at end of a line
. Matches any single character
[ ] Matches any character(s) inside the brackets
[^ ] Matches any character(s) not inside the brackets
[ - ] Matches any character in range on either side of a dash
* Matches preceding pattern zero or more times
+ Matches preceding pattern one or more times
? Matches preceding pattern at most once
() Saves a matched expression and uses it in a later match

Note that more than one of these metacharacters can be used in a single regular expression in order to create complex search patterns. For example, the pattern [^ab1-9] says to match any character sequence that does not begin with the characters "a", "b", or the characters "1" through "9".

Definition at line 79 of file vul_reg_exp.h.

Constructor & Destructor Documentation

vul_reg_exp::vul_reg_exp ( ) [inline]

Creates an empty regular expression.

Definition at line 98 of file vul_reg_exp.h.

vul_reg_exp::vul_reg_exp ( char const * s ) [inline]

Creates a regular expression from string s, and compiles s.

Definition at line 100 of file vul_reg_exp.h.

vul_reg_exp::vul_reg_exp ( vul_reg_exp const & rxp )

Copy constructor.

Copies the given regular expression.

Definition at line 126 of file vul_reg_exp.cxx.

vul_reg_exp::~vul_reg_exp ( ) [inline]

Frees space allocated for regular expression.

Definition at line 104 of file vul_reg_exp.h.

Member Function Documentation

void vul_reg_exp::clear_bufs ( ) [inline, private]

private function to clear startp[] and endp[].

Definition at line 144 of file vul_reg_exp.h.

void vul_reg_exp::compile ( char const * exp )

Compiles char* --> regexp.

Compile a regular expression into internal code for later pattern matching.

Definition at line 393 of file vul_reg_exp.cxx.

bool vul_reg_exp::deep_equal ( vul_reg_exp const & rxp ) const

Same regexp and state?.

Returns true if have the same compiled regular expressions and the same start and end pointers.

Definition at line 169 of file vul_reg_exp.cxx.

vcl_ptrdiff_t vul_reg_exp::end ( ) const [inline]

Returns the end index of the last item found.

Definition at line 114 of file vul_reg_exp.h.

vcl_ptrdiff_t vul_reg_exp::end ( long n ) const [inline]

Return end index of nth submatch.

end(0) is the end of the full match.

Definition at line 131 of file vul_reg_exp.h.

bool vul_reg_exp::find ( char const * string )

true if regexp in char* arg.

Matches the regular expression to the given string.

Returns true if found, and sets start and end indexes accordingly.

Definition at line 949 of file vul_reg_exp.cxx.

bool vul_reg_exp::find ( vcl_string const & s )

true if regexp in char* arg.

Definition at line 940 of file vul_reg_exp.cxx.

bool vul_reg_exp::is_valid ( ) const [inline]

Returns true if a valid RE is compiled and ready for pattern matching.

Definition at line 122 of file vul_reg_exp.h.

vcl_string vul_reg_exp::match ( int n ) const [inline]

Return nth submatch as a string.

Definition at line 133 of file vul_reg_exp.h.

bool vul_reg_exp::operator!= ( vul_reg_exp const & r ) const [inline]

Inequality operator.

Definition at line 118 of file vul_reg_exp.h.

bool vul_reg_exp::operator== ( vul_reg_exp const & rxp ) const

Equality operator.

Returns true if two regular expressions have the same compiled program for pattern matching.

Definition at line 153 of file vul_reg_exp.cxx.

const char * vul_reg_exp::protect ( char c ) [static]

Return an expression that will match precisely c.

The returned string is owned by the function, and will be overwritten in subsequent calls.

This should be in thread local storage.

Definition at line 324 of file vul_reg_exp.cxx.

void vul_reg_exp::set_invalid ( ) [inline]

Invalidates regular expression.

Definition at line 124 of file vul_reg_exp.h.

vcl_ptrdiff_t vul_reg_exp::start ( ) const [inline]

Returns the start index of the last item found.

Definition at line 112 of file vul_reg_exp.h.

vcl_ptrdiff_t vul_reg_exp::start ( long n ) const [inline]

Return start index of nth submatch.

start(0) is the start of the full match.

Definition at line 128 of file vul_reg_exp.h.

Member Data Documentation

const char* vul_reg_exp::endp[vul_reg_exp_nsubexp] [private]

anchor point of end position for n-th matching regular expression.

Definition at line 84 of file vul_reg_exp.h.

char* vul_reg_exp::program [private]

Definition at line 93 of file vul_reg_exp.h.

int vul_reg_exp::progsize [private]

Definition at line 94 of file vul_reg_exp.h.

char vul_reg_exp::reganch [private]

Internal use only.

Definition at line 88 of file vul_reg_exp.h.

int vul_reg_exp::regmlen [private]

Internal use only.

Definition at line 92 of file vul_reg_exp.h.

const char* vul_reg_exp::regmust [private]

Internal use only.

Definition at line 90 of file vul_reg_exp.h.

char vul_reg_exp::regstart [private]

Internal use only.

Definition at line 86 of file vul_reg_exp.h.

const char* vul_reg_exp::searchstring [private]

Definition at line 95 of file vul_reg_exp.h.

const char* vul_reg_exp::startp[vul_reg_exp_nsubexp] [private]

anchor point of start position for n-th matching regular expression.

Definition at line 82 of file vul_reg_exp.h.

The documentation for this class was generated from the following files:

core/vul/vul_reg_exp.h
core/vul/vul_reg_exp.cxx

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation