vul_reg_exp Class Reference

#include <vul_reg_exp.h>

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.

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

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 & )

Copy constructor.

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 * )

Compiles char* --> regexp.

Definition at line 393 of file vul_reg_exp.cxx.

bool vul_reg_exp::deep_equal ( vul_reg_exp const & ) const

Same regexp and state?.

Definition at line 169 of file vul_reg_exp.cxx.

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.

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.

bool vul_reg_exp::find ( vcl_string const & )

true if regexp in char* arg.

Definition at line 940 of file vul_reg_exp.cxx.

bool vul_reg_exp::find ( char const * string )

true if regexp in char* arg.
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::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 & ) const

Equality operator.

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.
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 ( 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.

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.

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

Generated on Thu Jan 10 14:41:01 2008 for core/vul by

1.4.4


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