glibmm 2.83.1
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Perl-compatible regular expressions - matches strings against regular expressions. More...
#include <glibmm/regex.h>
Static Public Member Functions | |
static Glib::RefPtr< Glib::Regex > | create (Glib::UStringView pattern, CompileFlags compile_options=CompileFlags::DEFAULT, MatchFlags match_options=MatchFlags::DEFAULT) |
static Glib::ustring | escape_string (const Glib::ustring &string) |
static bool | match_simple (Glib::UStringView pattern, Glib::UStringView string, CompileFlags compile_options=CompileFlags::DEFAULT, MatchFlags match_options=MatchFlags::DEFAULT) |
Scans for a match in string for pattern. | |
static std::vector< Glib::ustring > | split_simple (Glib::UStringView pattern, Glib::UStringView string, CompileFlags compile_options=CompileFlags::DEFAULT, MatchFlags match_options=MatchFlags::DEFAULT) |
Breaks the string on the pattern, and returns an array of the tokens. | |
static bool | check_replacement (Glib::UStringView replacement, gboolean *has_references) |
Checks whether replacement is a valid replacement string (see g_regex_replace()), i.e. that all escape sequences in it are valid. | |
Protected Member Functions | |
void | operator delete (void *, std::size_t) |
Related Symbols | |
(Note that these are not member symbols.) | |
Glib::RefPtr< Glib::Regex > | wrap (GRegex *object, bool take_copy=false) |
A Glib::wrap() method for this object. | |
Perl-compatible regular expressions - matches strings against regular expressions.
The Glib::Regex functions implement regular expression pattern matching using syntax and semantics similar to Perl regular expression.
Some functions accept a start_position argument, setting it differs from just passing over a shortened string and setting Glib::Regex::MatchFlags::NOTBOL in the case of a pattern that begins with any kind of lookbehind assertion. For example, consider the pattern "\Biss\B" which finds occurrences of "iss" in the middle of words. ("\B" matches only if the current position in the subject is not a word boundary.) When applied to the string "Mississipi" from the fourth byte, namely "issipi", it does not match, because "\B" is always false at the start of the subject, which is deemed to be a word boundary. However, if the entire string is passed , but with start_position set to 4, it finds the second occurrence of "iss" because it is able to look behind the starting point to discover that it is preceded by a letter.
Note that, unless you set the Glib::Regex::CompileFlags::RAW flag, all the strings passed to these functions must be encoded in UTF-8. The lengths and the positions inside the strings are in bytes and not in characters, so, for instance, "\xc3\xa0" (i.e. "Ã ") is two bytes long but it is treated as a single character. If you set Glib::Regex::CompileFlags::RAW the strings can be non-valid UTF-8 strings and a byte is treated as a character, so "\xc3\xa0" is two bytes and two characters long.
When matching a pattern, "\n" matches only against a "\n" character in the string, and "\r" matches only a "\r" character. To match any newline sequence use "\R". This particular group matches either the two-character sequence CR + LF ("\r\n"), or one of the single characters LF (linefeed, U+000A, "\n"), VT (vertical tab, U+000B, "\v"), FF (formfeed, U+000C, "\f"), CR (carriage return, U+000D, "\r"), NEL (next line, U+0085), LS (line separator, U+2028), or PS (paragraph separator, U+2029).
The behaviour of the dot, circumflex, and dollar metacharacters are affected by newline characters, the default is to recognize any newline character (the same characters recognized by "\R"). This can be changed with Glib::Regex::CompileFlags::NEWLINE_CR, Glib::Regex::CompileFlags::NEWLINE_LF and Glib::Regex::CompileFlags::NEWLINE_CRLF compile options, and with Glib::Regex::MatchFlags::NEWLINE_ANY, Glib::Regex::MatchFlags::NEWLINE_CR, Glib::Regex::MatchFlags::NEWLINE_LF and Glib::Regex::MatchFlags::NEWLINE_CRLF match options. These settings are also relevant when compiling a pattern if Glib::Regex::CompileFlags::EXTENDED is set, and an unescaped "#" outside a character class is encountered. This indicates a comment that lasts until after the next newline.
Creating and manipulating the same Glib::Regex class from different threads is not a problem as Glib::Regex does not modify its internal state between creation and destruction, on the other hand Glib::MatchInfo is not threadsafe.
The regular expressions low level functionalities are obtained through the excellent PCRE library written by Philip Hazel.
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delete |
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Checks whether replacement is a valid replacement string (see g_regex_replace()), i.e. that all escape sequences in it are valid.
If has_references is not nullptr
then replacement is checked for pattern references. For instance, replacement text 'foo\n' does not contain references and may be evaluated without information about actual match, but '\0\1' (whole match followed by first subpattern) requires valid MatchInfo object.
replacement | The replacement string. |
has_references | Location to store information about references in replacement or nullptr . |
Glib::RegexError |
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Glib::RegexError |
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int Glib::Regex::get_capture_count | ( | ) | const |
Returns the number of capturing subpatterns in the pattern.
CompileFlags Glib::Regex::get_compile_flags | ( | ) | const |
Returns the compile options that regex was created with.
Depending on the version of PCRE that is used, this may or may not include flags set by option expressions such as (?i)
found at the top-level within the compiled pattern.
bool Glib::Regex::get_has_cr_or_lf | ( | ) | const |
Checks whether the pattern contains explicit CR or LF references.
true
if the pattern contains explicit CR or LF references. MatchFlags Glib::Regex::get_match_flags | ( | ) | const |
Returns the match options that regex was created with.
int Glib::Regex::get_max_backref | ( | ) | const |
Returns the number of the highest back reference in the pattern, or 0 if the pattern does not contain back references.
int Glib::Regex::get_max_lookbehind | ( | ) | const |
Gets the number of characters in the longest lookbehind assertion in the pattern.
This information is useful when doing multi-segment matching using the partial matching facilities.
Glib::ustring Glib::Regex::get_pattern | ( | ) | const |
Gets the pattern string associated with regex, i.e. a copy of the string passed to g_regex_new().
int Glib::Regex::get_string_number | ( | Glib::UStringView | name | ) | const |
Retrieves the number of the subexpression named name.
name | Name of the subexpression. |
GRegex * Glib::Regex::gobj | ( | ) |
Provides access to the underlying C instance.
GRegex * Glib::Regex::gobj_copy | ( | ) | const |
Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
bool Glib::Regex::match | ( | Glib::UStringView | string, |
Glib::MatchInfo & | match_info, | ||
MatchFlags | match_options = MatchFlags::DEFAULT |
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) |
Scans for a match in string for the pattern in regex.
The match_options are combined with the match options specified when the regex structure was created, letting you have more flexibility in reusing Regex structures.
Unless Glib::Regex::CompileFlags::RAW is specified in the options, string must be valid UTF-8.
A MatchInfo structure, used to get information on the match, is stored in match_info if not nullptr
. Note that if match_info is not nullptr
then it is created even if the function returns false
, i.e. you must free it regardless if regular expression actually matched.
To retrieve all the non-overlapping matches of the pattern in string you can use g_match_info_next().
[C example ellipted]
string is not copied and is used in MatchInfo internally. If you use any MatchInfo method (except g_match_info_free()) after freeing or modifying string then the behaviour is undefined.
string | The string to scan for matches. |
match_options | Match options. |
match_info | Pointer to location where to store the MatchInfo, or nullptr if you do not need it. |
true
is the string matched, false
otherwise. bool Glib::Regex::match | ( | Glib::UStringView | string, |
gssize | string_len, | ||
int | start_position, | ||
Glib::MatchInfo & | match_info, | ||
MatchFlags | match_options = MatchFlags::DEFAULT |
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) |
Scans for a match in string for the pattern in regex.
The match_options are combined with the match options specified when the regex structure was created, letting you have more flexibility in reusing Regex structures.
Setting start_position differs from just passing over a shortened string and setting Glib::Regex::MatchFlags::NOTBOL in the case of a pattern that begins with any kind of lookbehind assertion, such as "\\b".
Unless Glib::Regex::CompileFlags::RAW is specified in the options, string must be valid UTF-8.
A MatchInfo structure, used to get information on the match, is stored in match_info if not nullptr
. Note that if match_info is not nullptr
then it is created even if the function returns false
, i.e. you must free it regardless if regular expression actually matched.
string is not copied and is used in MatchInfo internally. If you use any MatchInfo method (except g_match_info_free()) after freeing or modifying string then the behaviour is undefined.
To retrieve all the non-overlapping matches of the pattern in string you can use g_match_info_next().
[C example ellipted]
string | The string to scan for matches. |
string_len | The length of string, in bytes, or -1 if string is nul-terminated. |
start_position | Starting index of the string to match, in bytes. |
match_options | Match options. |
match_info | Pointer to location where to store the MatchInfo, or nullptr if you do not need it. |
true
is the string matched, false
otherwise.Glib::RegexError |
bool Glib::Regex::match | ( | Glib::UStringView | string, |
gssize | string_len, | ||
int | start_position, | ||
MatchFlags | match_options | ||
) |
A match() method with a string length and start position not requiring a Glib::MatchInfo.
bool Glib::Regex::match | ( | Glib::UStringView | string, |
int | start_position, | ||
Glib::MatchInfo & | match_info, | ||
MatchFlags | match_options = MatchFlags::DEFAULT |
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) |
A match() method with a start position and a Glib::MatchInfo.
Glib::RegexError |
bool Glib::Regex::match | ( | Glib::UStringView | string, |
int | start_position, | ||
MatchFlags | match_options | ||
) |
A match() method with a start position not requiring a Glib::MatchInfo.
Glib::RegexError |
bool Glib::Regex::match | ( | Glib::UStringView | string, |
MatchFlags | match_options = MatchFlags::DEFAULT |
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) |
A match() method not requiring a Glib::MatchInfo.
bool Glib::Regex::match_all | ( | Glib::UStringView | string, |
Glib::MatchInfo & | match_info, | ||
MatchFlags | match_options = MatchFlags::DEFAULT |
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) |
Using the standard algorithm for regular expression matching only the longest match in the string is retrieved.
This function uses a different algorithm so it can retrieve all the possible matches. For more documentation see g_regex_match_all_full().
A MatchInfo structure, used to get information on the match, is stored in match_info if not nullptr
. Note that if match_info is not nullptr
then it is created even if the function returns false
, i.e. you must free it regardless if regular expression actually matched.
string is not copied and is used in MatchInfo internally. If you use any MatchInfo method (except g_match_info_free()) after freeing or modifying string then the behaviour is undefined.
string | The string to scan for matches. |
match_options | Match options. |
match_info | Pointer to location where to store the MatchInfo, or nullptr if you do not need it. |
true
is the string matched, false
otherwise. bool Glib::Regex::match_all | ( | Glib::UStringView | string, |
gssize | string_len, | ||
int | start_position, | ||
Glib::MatchInfo & | match_info, | ||
MatchFlags | match_options = MatchFlags::DEFAULT |
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) |
Using the standard algorithm for regular expression matching only the longest match in the string is retrieved, it is not possible to obtain all the available matches.
For instance matching "<a> <b> <c>"
against the pattern "<.*>"
you get "<a> <b> <c>"
.
This function uses a different algorithm (called DFA, i.e. deterministic finite automaton), so it can retrieve all the possible matches, all starting at the same point in the string. For instance matching "<a> <b> <c>"
against the pattern "<.*>"
you would obtain three matches: "<a> <b> <c>"
, "<a> <b>"
and "<a>"
.
The number of matched strings is retrieved using g_match_info_get_match_count(). To obtain the matched strings and their position you can use, respectively, g_match_info_fetch() and g_match_info_fetch_pos(). Note that the strings are returned in reverse order of length; that is, the longest matching string is given first.
Note that the DFA algorithm is slower than the standard one and it is not able to capture substrings, so backreferences do not work.
Setting start_position differs from just passing over a shortened string and setting Glib::Regex::MatchFlags::NOTBOL in the case of a pattern that begins with any kind of lookbehind assertion, such as "\\b".
Unless Glib::Regex::CompileFlags::RAW is specified in the options, string must be valid UTF-8.
A MatchInfo structure, used to get information on the match, is stored in match_info if not nullptr
. Note that if match_info is not nullptr
then it is created even if the function returns false
, i.e. you must free it regardless if regular expression actually matched.
string is not copied and is used in MatchInfo internally. If you use any MatchInfo method (except g_match_info_free()) after freeing or modifying string then the behaviour is undefined.
string | The string to scan for matches. |
string_len | The length of string, in bytes, or -1 if string is nul-terminated. |
start_position | Starting index of the string to match, in bytes. |
match_options | Match options. |
match_info | Pointer to location where to store the MatchInfo, or nullptr if you do not need it. |
true
is the string matched, false
otherwise.Glib::RegexError |
bool Glib::Regex::match_all | ( | Glib::UStringView | string, |
gssize | string_len, | ||
int | start_position, | ||
MatchFlags | match_options | ||
) |
A match_all() method with a start position and a string length not requiring a Glib::MatchInfo.
Glib::RegexError |
bool Glib::Regex::match_all | ( | Glib::UStringView | string, |
int | start_position, | ||
Glib::MatchInfo & | match_info, | ||
MatchFlags | match_options = MatchFlags::DEFAULT |
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) |
A match_all() method with a start positon and a Glib::MatchInfo.
Glib::RegexError |
bool Glib::Regex::match_all | ( | Glib::UStringView | string, |
int | start_position, | ||
MatchFlags | match_options | ||
) |
A match_all() method with a start position not requiring a Glib::MatchInfo.
Glib::RegexError |
bool Glib::Regex::match_all | ( | Glib::UStringView | string, |
MatchFlags | match_options = MatchFlags::DEFAULT |
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) |
A match_all() method not requiring a Glib::MatchInfo.
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Scans for a match in string for pattern.
This function is equivalent to g_regex_match() but it does not require to compile the pattern with g_regex_new(), avoiding some lines of code when you need just to do a match without extracting substrings, capture counts, and so on.
If this function is to be called on the same pattern more than once, it's more efficient to compile the pattern once with g_regex_new() and then use g_regex_match().
pattern | The regular expression. |
string | The string to scan for matches. |
compile_options | Compile options for the regular expression, or 0. |
match_options | Match options, or 0. |
true
if the string matched, false
otherwise. void Glib::Regex::reference | ( | ) | const |
Increment the reference count for this object.
You should never need to do this manually - use the object via a RefPtr instead.
Glib::ustring Glib::Regex::replace | ( | const gchar * | string, |
gssize | string_len, | ||
int | start_position, | ||
Glib::UStringView | replacement, | ||
MatchFlags | match_options = MatchFlags::DEFAULT |
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) |
Replaces all occurrences of the pattern in regex with the replacement text.
Backreferences of the form \\number
or \\g<number>
in the replacement text are interpolated by the number-th captured subexpression of the match, \\g<name>
refers to the captured subexpression with the given name. \\0
refers to the complete match, but \\0
followed by a number is the octal representation of a character. To include a literal \\
in the replacement, write \\\\\\\\
.
There are also escapes that changes the case of the following text:
If you do not need to use backreferences use g_regex_replace_literal().
The replacement string must be UTF-8 encoded even if Glib::Regex::CompileFlags::RAW was passed to g_regex_new(). If you want to use not UTF-8 encoded strings you can use g_regex_replace_literal().
Setting start_position differs from just passing over a shortened string and setting Glib::Regex::MatchFlags::NOTBOL in the case of a pattern that begins with any kind of lookbehind assertion, such as "\\b".
string | The string to perform matches against. |
string_len | The length of string, in bytes, or -1 if string is nul-terminated. |
start_position | Starting index of the string to match, in bytes. |
replacement | Text to replace each match with. |
match_options | Options for the match. |
Glib::RegexError |
Glib::ustring Glib::Regex::replace | ( | Glib::UStringView | string, |
int | start_position, | ||
Glib::UStringView | replacement, | ||
MatchFlags | match_options | ||
) |
Glib::RegexError |
Glib::ustring Glib::Regex::replace_eval | ( | Glib::UStringView | string, |
gssize | string_len, | ||
int | start_position, | ||
MatchFlags | match_options, | ||
GRegexEvalCallback | eval, | ||
gpointer | user_data | ||
) |
Replaces occurrences of the pattern in regex with the output of eval for that occurrence.
Setting start_position differs from just passing over a shortened string and setting Glib::Regex::MatchFlags::NOTBOL in the case of a pattern that begins with any kind of lookbehind assertion, such as "\\b".
The following example uses g_regex_replace_eval() to replace multiple strings at once:
[C example ellipted]
string | String to perform matches against. |
string_len | The length of string, in bytes, or -1 if string is nul-terminated. |
start_position | Starting index of the string to match, in bytes. |
match_options | Options for the match. |
eval | A function to call for each match. |
user_data | User data to pass to the function. |
Glib::RegexError |
Glib::ustring Glib::Regex::replace_literal | ( | const gchar * | string, |
gssize | string_len, | ||
int | start_position, | ||
Glib::UStringView | replacement, | ||
MatchFlags | match_options = MatchFlags::DEFAULT |
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) |
Replaces all occurrences of the pattern in regex with the replacement text.
replacement is replaced literally, to include backreferences use g_regex_replace().
Setting start_position differs from just passing over a shortened string and setting Glib::Regex::MatchFlags::NOTBOL in the case of a pattern that begins with any kind of lookbehind assertion, such as "\\b".
string | The string to perform matches against. |
string_len | The length of string, in bytes, or -1 if string is nul-terminated. |
start_position | Starting index of the string to match, in bytes. |
replacement | Text to replace each match with. |
match_options | Options for the match. |
Glib::RegexError |
Glib::ustring Glib::Regex::replace_literal | ( | Glib::UStringView | string, |
int | start_position, | ||
Glib::UStringView | replacement, | ||
MatchFlags | match_options | ||
) |
Glib::RegexError |
std::vector< Glib::ustring > Glib::Regex::split | ( | const gchar * | string, |
gssize | string_len, | ||
int | start_position, | ||
MatchFlags | match_options = MatchFlags::DEFAULT , |
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int | max_tokens = 0 |
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) | const |
Breaks the string on the pattern, and returns an array of the tokens.
If the pattern contains capturing parentheses, then the text for each of the substrings will also be returned. If the pattern does not match anywhere in the string, then the whole string is returned as the first token.
As a special case, the result of splitting the empty string "" is an empty vector, not a vector containing a single string. The reason for this special case is that being able to represent an empty vector is typically more useful than consistent handling of empty elements. If you do need to represent empty elements, you'll need to check for the empty string before calling this function.
A pattern that can match empty strings splits string into separate characters wherever it matches the empty string between characters. For example splitting "ab c" using as a separator "\\s*", you will get "a", "b" and "c".
Setting start_position differs from just passing over a shortened string and setting Glib::Regex::MatchFlags::NOTBOL in the case of a pattern that begins with any kind of lookbehind assertion, such as "\\b".
string | The string to split with the pattern. |
string_len | The length of string, in bytes, or -1 if string is nul-terminated. |
start_position | Starting index of the string to match, in bytes. |
match_options | Match time option flags. |
max_tokens | The maximum number of tokens to split string into. If this is less than 1, the string is split completely. |
nullptr
-terminated gchar ** array.Glib::RegexError |
std::vector< Glib::ustring > Glib::Regex::split | ( | Glib::UStringView | string, |
int | start_position, | ||
MatchFlags | match_options, | ||
int | max_tokens | ||
) | const |
Glib::RegexError |
std::vector< Glib::ustring > Glib::Regex::split | ( | Glib::UStringView | string, |
MatchFlags | match_options = MatchFlags::DEFAULT |
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) |
Breaks the string on the pattern, and returns an array of the tokens.
If the pattern contains capturing parentheses, then the text for each of the substrings will also be returned. If the pattern does not match anywhere in the string, then the whole string is returned as the first token.
As a special case, the result of splitting the empty string "" is an empty vector, not a vector containing a single string. The reason for this special case is that being able to represent an empty vector is typically more useful than consistent handling of empty elements. If you do need to represent empty elements, you'll need to check for the empty string before calling this function.
A pattern that can match empty strings splits string into separate characters wherever it matches the empty string between characters. For example splitting "ab c" using as a separator "\\s*", you will get "a", "b" and "c".
string | The string to split with the pattern. |
match_options | Match time option flags. |
nullptr
-terminated gchar ** array.
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static |
Breaks the string on the pattern, and returns an array of the tokens.
If the pattern contains capturing parentheses, then the text for each of the substrings will also be returned. If the pattern does not match anywhere in the string, then the whole string is returned as the first token.
This function is equivalent to g_regex_split() but it does not require to compile the pattern with g_regex_new(), avoiding some lines of code when you need just to do a split without extracting substrings, capture counts, and so on.
If this function is to be called on the same pattern more than once, it's more efficient to compile the pattern once with g_regex_new() and then use g_regex_split().
As a special case, the result of splitting the empty string "" is an empty vector, not a vector containing a single string. The reason for this special case is that being able to represent an empty vector is typically more useful than consistent handling of empty elements. If you do need to represent empty elements, you'll need to check for the empty string before calling this function.
A pattern that can match empty strings splits string into separate characters wherever it matches the empty string between characters. For example splitting "ab c" using as a separator "\\s*", you will get "a", "b" and "c".
pattern | The regular expression. |
string | The string to scan for matches. |
compile_options | Compile options for the regular expression, or 0. |
match_options | Match options, or 0. |
nullptr
-terminated array of strings. void Glib::Regex::unreference | ( | ) | const |
Decrement the reference count for this object.
You should never need to do this manually - use the object via a RefPtr instead.
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related |
A Glib::wrap() method for this object.
object | The C instance. |
take_copy | False if the result should take ownership of the C instance. True if it should take a new copy or ref. |