Perl-compatible regular expressions

Perl-compatible regular expressions — matches strings against regular expressions

Synopsis

#include <glib.h>

enum                GRegexError;
#define             G_REGEX_ERROR
enum                GRegexCompileFlags;
enum                GRegexMatchFlags;
                    GRegex;
gboolean            (*GRegexEvalCallback)               (const GMatchInfo *match_info,
                                                         GString *result,
                                                         gpointer user_data);
GRegex *            g_regex_new                         (const gchar *pattern,
                                                         GRegexCompileFlags compile_options,
                                                         GRegexMatchFlags match_options,
                                                         GError **error);
GRegex *            g_regex_ref                         (GRegex *regex);
void                g_regex_unref                       (GRegex *regex);
const gchar *       g_regex_get_pattern                 (const GRegex *regex);
gint                g_regex_get_max_backref             (const GRegex *regex);
gint                g_regex_get_capture_count           (const GRegex *regex);
gint                g_regex_get_string_number           (const GRegex *regex,
                                                         const gchar *name);
gchar *             g_regex_escape_string               (const gchar *string,
                                                         gint length);
gboolean            g_regex_match_simple                (const gchar *pattern,
                                                         const gchar *string,
                                                         GRegexCompileFlags compile_options,
                                                         GRegexMatchFlags match_options);
gboolean            g_regex_match                       (const GRegex *regex,
                                                         const gchar *string,
                                                         GRegexMatchFlags match_options,
                                                         GMatchInfo **match_info);
gboolean            g_regex_match_full                  (const GRegex *regex,
                                                         const gchar *string,
                                                         gssize string_len,
                                                         gint start_position,
                                                         GRegexMatchFlags match_options,
                                                         GMatchInfo **match_info,
                                                         GError **error);
gboolean            g_regex_match_all                   (const GRegex *regex,
                                                         const gchar *string,
                                                         GRegexMatchFlags match_options,
                                                         GMatchInfo **match_info);
gboolean            g_regex_match_all_full              (const GRegex *regex,
                                                         const gchar *string,
                                                         gssize string_len,
                                                         gint start_position,
                                                         GRegexMatchFlags match_options,
                                                         GMatchInfo **match_info,
                                                         GError **error);
gchar **            g_regex_split_simple                (const gchar *pattern,
                                                         const gchar *string,
                                                         GRegexCompileFlags compile_options,
                                                         GRegexMatchFlags match_options);
gchar **            g_regex_split                       (const GRegex *regex,
                                                         const gchar *string,
                                                         GRegexMatchFlags match_options);
gchar **            g_regex_split_full                  (const GRegex *regex,
                                                         const gchar *string,
                                                         gssize string_len,
                                                         gint start_position,
                                                         GRegexMatchFlags match_options,
                                                         gint max_tokens,
                                                         GError **error);
gchar *             g_regex_replace                     (const GRegex *regex,
                                                         const gchar *string,
                                                         gssize string_len,
                                                         gint start_position,
                                                         const gchar *replacement,
                                                         GRegexMatchFlags match_options,
                                                         GError **error);
gchar *             g_regex_replace_literal             (const GRegex *regex,
                                                         const gchar *string,
                                                         gssize string_len,
                                                         gint start_position,
                                                         const gchar *replacement,
                                                         GRegexMatchFlags match_options,
                                                         GError **error);
gchar *             g_regex_replace_eval                (const GRegex *regex,
                                                         const gchar *string,
                                                         gssize string_len,
                                                         gint start_position,
                                                         GRegexMatchFlags match_options,
                                                         GRegexEvalCallback eval,
                                                         gpointer user_data,
                                                         GError **error);
gboolean            g_regex_check_replacement           (const gchar *replacement,
                                                         gboolean *has_references,
                                                         GError **error);
                    GMatchInfo;
GRegex *            g_match_info_get_regex              (const GMatchInfo *match_info);
const gchar *       g_match_info_get_string             (const GMatchInfo *match_info);
void                g_match_info_free                   (GMatchInfo *match_info);
gboolean            g_match_info_matches                (const GMatchInfo *match_info);
gboolean            g_match_info_next                   (GMatchInfo *match_info,
                                                         GError **error);
gint                g_match_info_get_match_count        (const GMatchInfo *match_info);
gboolean            g_match_info_is_partial_match       (const GMatchInfo *match_info);
gchar *             g_match_info_expand_references      (const GMatchInfo *match_info,
                                                         const gchar *string_to_expand,
                                                         GError **error);
gchar *             g_match_info_fetch                  (const GMatchInfo *match_info,
                                                         gint match_num);
gboolean            g_match_info_fetch_pos              (const GMatchInfo *match_info,
                                                         gint match_num,
                                                         gint *start_pos,
                                                         gint *end_pos);
gchar *             g_match_info_fetch_named            (const GMatchInfo *match_info,
                                                         const gchar *name);
gboolean            g_match_info_fetch_named_pos        (const GMatchInfo *match_info,
                                                         const gchar *name,
                                                         gint *start_pos,
                                                         gint *end_pos);
gchar **            g_match_info_fetch_all              (const GMatchInfo *match_info);

Description

The g_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 G_REGEX_MATCH_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 G_REGEX_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. "à") is two bytes long but it is treated as a single character. If you set G_REGEX_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 G_REGEX_NEWLINE_CR, G_REGEX_NEWLINE_LF and G_REGEX_NEWLINE_CRLF compile options, and with G_REGEX_MATCH_NEWLINE_ANY, G_REGEX_MATCH_NEWLINE_CR, G_REGEX_MATCH_NEWLINE_LF and G_REGEX_MATCH_NEWLINE_CRLF match options. These settings are also relevant when compiling a pattern if G_REGEX_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 GRegex structure from different threads is not a problem as GRegex does not modify its internal state between creation and destruction, on the other hand GMatchInfo is not threadsafe.

The regular expressions low level functionalities are obtained through the excellent PCRE library written by Philip Hazel.

Details

enum GRegexError

typedef enum {
  G_REGEX_ERROR_COMPILE,
  G_REGEX_ERROR_OPTIMIZE,
  G_REGEX_ERROR_REPLACE,
  G_REGEX_ERROR_MATCH,
  G_REGEX_ERROR_INTERNAL,

  /* These are the error codes from PCRE + 100 */
  G_REGEX_ERROR_STRAY_BACKSLASH = 101,
  G_REGEX_ERROR_MISSING_CONTROL_CHAR = 102,
  G_REGEX_ERROR_UNRECOGNIZED_ESCAPE = 103,
  G_REGEX_ERROR_QUANTIFIERS_OUT_OF_ORDER = 104,
  G_REGEX_ERROR_QUANTIFIER_TOO_BIG = 105,
  G_REGEX_ERROR_UNTERMINATED_CHARACTER_CLASS = 106,
  G_REGEX_ERROR_INVALID_ESCAPE_IN_CHARACTER_CLASS = 107,
  G_REGEX_ERROR_RANGE_OUT_OF_ORDER = 108,
  G_REGEX_ERROR_NOTHING_TO_REPEAT = 109,
  G_REGEX_ERROR_UNRECOGNIZED_CHARACTER = 112,
  G_REGEX_ERROR_POSIX_NAMED_CLASS_OUTSIDE_CLASS = 113,
  G_REGEX_ERROR_UNMATCHED_PARENTHESIS = 114,
  G_REGEX_ERROR_INEXISTENT_SUBPATTERN_REFERENCE = 115,
  G_REGEX_ERROR_UNTERMINATED_COMMENT = 118,
  G_REGEX_ERROR_EXPRESSION_TOO_LARGE = 120,
  G_REGEX_ERROR_MEMORY_ERROR = 121,
  G_REGEX_ERROR_VARIABLE_LENGTH_LOOKBEHIND = 125,
  G_REGEX_ERROR_MALFORMED_CONDITION = 126,
  G_REGEX_ERROR_TOO_MANY_CONDITIONAL_BRANCHES = 127,
  G_REGEX_ERROR_ASSERTION_EXPECTED = 128,
  G_REGEX_ERROR_UNKNOWN_POSIX_CLASS_NAME = 130,
  G_REGEX_ERROR_POSIX_COLLATING_ELEMENTS_NOT_SUPPORTED = 131,
  G_REGEX_ERROR_HEX_CODE_TOO_LARGE = 134,
  G_REGEX_ERROR_INVALID_CONDITION = 135,
  G_REGEX_ERROR_SINGLE_BYTE_MATCH_IN_LOOKBEHIND = 136,
  G_REGEX_ERROR_INFINITE_LOOP = 140,
  G_REGEX_ERROR_MISSING_SUBPATTERN_NAME_TERMINATOR = 142,
  G_REGEX_ERROR_DUPLICATE_SUBPATTERN_NAME = 143,
  G_REGEX_ERROR_MALFORMED_PROPERTY = 146,
  G_REGEX_ERROR_UNKNOWN_PROPERTY = 147,
  G_REGEX_ERROR_SUBPATTERN_NAME_TOO_LONG = 148,
  G_REGEX_ERROR_TOO_MANY_SUBPATTERNS = 149,
  G_REGEX_ERROR_INVALID_OCTAL_VALUE = 151,
  G_REGEX_ERROR_TOO_MANY_BRANCHES_IN_DEFINE = 154,
  G_REGEX_ERROR_DEFINE_REPETION = 155,
  G_REGEX_ERROR_INCONSISTENT_NEWLINE_OPTIONS = 156,
  G_REGEX_ERROR_MISSING_BACK_REFERENCE = 157
} GRegexError;

Error codes returned by regular expressions functions.

G_REGEX_ERROR_COMPILE

Compilation of the regular expression failed.

G_REGEX_ERROR_OPTIMIZE

Optimization of the regular expression failed.

G_REGEX_ERROR_REPLACE

Replacement failed due to an ill-formed replacement string.

G_REGEX_ERROR_MATCH

The match process failed.

G_REGEX_ERROR_INTERNAL

Internal error of the regular expression engine. Since 2.16

G_REGEX_ERROR_STRAY_BACKSLASH

"\\" at end of pattern. Since 2.16

G_REGEX_ERROR_MISSING_CONTROL_CHAR

"\\c" at end of pattern. Since 2.16

G_REGEX_ERROR_UNRECOGNIZED_ESCAPE

Unrecognized character follows "\\". Since 2.16

G_REGEX_ERROR_QUANTIFIERS_OUT_OF_ORDER

Numbers out of order in "{}" quantifier. Since 2.16

G_REGEX_ERROR_QUANTIFIER_TOO_BIG

Number too big in "{}" quantifier. Since 2.16

G_REGEX_ERROR_UNTERMINATED_CHARACTER_CLASS

Missing terminating "]" for character class. Since 2.16

G_REGEX_ERROR_INVALID_ESCAPE_IN_CHARACTER_CLASS

Invalid escape sequence in character class. Since 2.16

G_REGEX_ERROR_RANGE_OUT_OF_ORDER

Range out of order in character class. Since 2.16

G_REGEX_ERROR_NOTHING_TO_REPEAT

Nothing to repeat. Since 2.16

G_REGEX_ERROR_UNRECOGNIZED_CHARACTER

Unrecognized character after "(?", "(?<" or "(?P". Since 2.16

G_REGEX_ERROR_POSIX_NAMED_CLASS_OUTSIDE_CLASS

POSIX named classes are supported only within a class. Since 2.16

G_REGEX_ERROR_UNMATCHED_PARENTHESIS

Missing terminating ")" or ")" without opening "(". Since 2.16

G_REGEX_ERROR_INEXISTENT_SUBPATTERN_REFERENCE

Reference to non-existent subpattern. Since 2.16

G_REGEX_ERROR_UNTERMINATED_COMMENT

Missing terminating ")" after comment. Since 2.16

G_REGEX_ERROR_EXPRESSION_TOO_LARGE

Regular expression too large. Since 2.16

G_REGEX_ERROR_MEMORY_ERROR

Failed to get memory. Since 2.16

G_REGEX_ERROR_VARIABLE_LENGTH_LOOKBEHIND

Lookbehind assertion is not fixed length. Since 2.16

G_REGEX_ERROR_MALFORMED_CONDITION

Malformed number or name after "(?(". Since 2.16

G_REGEX_ERROR_TOO_MANY_CONDITIONAL_BRANCHES

Conditional group contains more than two branches. Since 2.16

G_REGEX_ERROR_ASSERTION_EXPECTED

Assertion expected after "(?(". Since 2.16

G_REGEX_ERROR_UNKNOWN_POSIX_CLASS_NAME

Unknown POSIX class name. Since 2.16

G_REGEX_ERROR_POSIX_COLLATING_ELEMENTS_NOT_SUPPORTED

POSIX collating elements are not supported. Since 2.16

G_REGEX_ERROR_HEX_CODE_TOO_LARGE

Character value in "\\x{...}" sequence is too large. Since 2.16

G_REGEX_ERROR_INVALID_CONDITION

Invalid condition "(?(0)". Since 2.16

G_REGEX_ERROR_SINGLE_BYTE_MATCH_IN_LOOKBEHIND

\\C not allowed in lookbehind assertion. Since 2.16

G_REGEX_ERROR_INFINITE_LOOP

Recursive call could loop indefinitely. Since 2.16

G_REGEX_ERROR_MISSING_SUBPATTERN_NAME_TERMINATOR

Missing terminator in subpattern name. Since 2.16

G_REGEX_ERROR_DUPLICATE_SUBPATTERN_NAME

Two named subpatterns have the same name. Since 2.16

G_REGEX_ERROR_MALFORMED_PROPERTY

Malformed "\\P" or "\\p" sequence. Since 2.16

G_REGEX_ERROR_UNKNOWN_PROPERTY

Unknown property name after "\\P" or "\\p". Since 2.16

G_REGEX_ERROR_SUBPATTERN_NAME_TOO_LONG

Subpattern name is too long (maximum 32 characters). Since 2.16

G_REGEX_ERROR_TOO_MANY_SUBPATTERNS

Too many named subpatterns (maximum 10,000). Since 2.16

G_REGEX_ERROR_INVALID_OCTAL_VALUE

Octal value is greater than "\\377". Since 2.16

G_REGEX_ERROR_TOO_MANY_BRANCHES_IN_DEFINE

"DEFINE" group contains more than one branch. Since 2.16

G_REGEX_ERROR_DEFINE_REPETION

Repeating a "DEFINE" group is not allowed. Since 2.16

G_REGEX_ERROR_INCONSISTENT_NEWLINE_OPTIONS

Inconsistent newline options. Since 2.16

G_REGEX_ERROR_MISSING_BACK_REFERENCE

"\\g" is not followed by a braced name or an optionally braced non-zero number. Since 2.16

Since 2.14


G_REGEX_ERROR

#define G_REGEX_ERROR g_regex_error_quark ()

Error domain for regular expressions. Errors in this domain will be from the GRegexError enumeration. See GError for information on error domains.

Since 2.14


enum GRegexCompileFlags

typedef enum {
  G_REGEX_CASELESS          = 1 << 0,
  G_REGEX_MULTILINE         = 1 << 1,
  G_REGEX_DOTALL            = 1 << 2,
  G_REGEX_EXTENDED          = 1 << 3,
  G_REGEX_ANCHORED          = 1 << 4,
  G_REGEX_DOLLAR_ENDONLY    = 1 << 5,
  G_REGEX_UNGREEDY          = 1 << 9,
  G_REGEX_RAW               = 1 << 11,
  G_REGEX_NO_AUTO_CAPTURE   = 1 << 12,
  G_REGEX_OPTIMIZE          = 1 << 13,
  G_REGEX_DUPNAMES          = 1 << 19,
  G_REGEX_NEWLINE_CR        = 1 << 20,
  G_REGEX_NEWLINE_LF        = 1 << 21,
  G_REGEX_NEWLINE_CRLF      = G_REGEX_NEWLINE_CR | G_REGEX_NEWLINE_LF
} GRegexCompileFlags;

Flags specifying compile-time options.

G_REGEX_CASELESS

Letters in the pattern match both upper and lower case letters. It be changed within a pattern by a "(?i)" option setting.

G_REGEX_MULTILINE

By default, GRegex treats the strings as consisting of a single line of characters (even if it actually contains newlines). The "start of line" metacharacter ("^") matches only at the start of the string, while the "end of line" metacharacter ("$") matches only at the end of the string, or before a terminating newline (unless G_REGEX_DOLLAR_ENDONLY is set). When G_REGEX_MULTILINE is set, the "start of line" and "end of line" constructs match immediately following or immediately before any newline in the string, respectively, as well as at the very start and end. This can be changed within a pattern by a "(?m)" option setting.

G_REGEX_DOTALL

A dot metacharater (".") in the pattern matches all characters, including newlines. Without it, newlines are excluded. This option can be changed within a pattern by a ("?s") option setting.

G_REGEX_EXTENDED

Whitespace data characters in the pattern are totally ignored except when escaped or inside a character class. Whitespace does not include the VT character (code 11). In addition, characters between an unescaped "#" outside a character class and the next newline character, inclusive, are also ignored. This can be changed within a pattern by a "(?x)" option setting.

G_REGEX_ANCHORED

The pattern is forced to be "anchored", that is, it is constrained to match only at the first matching point in the string that is being searched. This effect can also be achieved by appropriate constructs in the pattern itself such as the "^" metacharater.

G_REGEX_DOLLAR_ENDONLY

A dollar metacharacter ("$") in the pattern matches only at the end of the string. Without this option, a dollar also matches immediately before the final character if it is a newline (but not before any other newlines). This option is ignored if G_REGEX_MULTILINE is set.

G_REGEX_UNGREEDY

Inverts the "greediness" of the quantifiers so that they are not greedy by default, but become greedy if followed by "?". It can also be set by a "(?U)" option setting within the pattern.

G_REGEX_RAW

Usually strings must be valid UTF-8 strings, using this flag they are considered as a raw sequence of bytes.

G_REGEX_NO_AUTO_CAPTURE

Disables the use of numbered capturing parentheses in the pattern. Any opening parenthesis that is not followed by "?" behaves as if it were followed by "?:" but named parentheses can still be used for capturing (and they acquire numbers in the usual way).

G_REGEX_OPTIMIZE

Optimize the regular expression. If the pattern will be used many times, then it may be worth the effort to optimize it to improve the speed of matches.

G_REGEX_DUPNAMES

Names used to identify capturing subpatterns need not be unique. This can be helpful for certain types of pattern when it is known that only one instance of the named subpattern can ever be matched.

G_REGEX_NEWLINE_CR

Usually any newline character is recognized, if this option is set, the only recognized newline character is '\r'.

G_REGEX_NEWLINE_LF

Usually any newline character is recognized, if this option is set, the only recognized newline character is '\n'.

G_REGEX_NEWLINE_CRLF

Usually any newline character is recognized, if this option is set, the only recognized newline character sequence is '\r\n'.

Since 2.14


enum GRegexMatchFlags

typedef enum {
  G_REGEX_MATCH_ANCHORED      = 1 << 4,
  G_REGEX_MATCH_NOTBOL        = 1 << 7,
  G_REGEX_MATCH_NOTEOL        = 1 << 8,
  G_REGEX_MATCH_NOTEMPTY      = 1 << 10,
  G_REGEX_MATCH_PARTIAL       = 1 << 15,
  G_REGEX_MATCH_NEWLINE_CR    = 1 << 20,
  G_REGEX_MATCH_NEWLINE_LF    = 1 << 21,
  G_REGEX_MATCH_NEWLINE_CRLF  = G_REGEX_MATCH_NEWLINE_CR | G_REGEX_MATCH_NEWLINE_LF,
  G_REGEX_MATCH_NEWLINE_ANY   = 1 << 22
} GRegexMatchFlags;

Flags specifying match-time options.

G_REGEX_MATCH_ANCHORED

The pattern is forced to be "anchored", that is, it is constrained to match only at the first matching point in the string that is being searched. This effect can also be achieved by appropriate constructs in the pattern itself such as the "^" metacharater.

G_REGEX_MATCH_NOTBOL

Specifies that first character of the string is not the beginning of a line, so the circumflex metacharacter should not match before it. Setting this without G_REGEX_MULTILINE (at compile time) causes circumflex never to match. This option affects only the behaviour of the circumflex metacharacter, it does not affect "\A".

G_REGEX_MATCH_NOTEOL

Specifies that the end of the subject string is not the end of a line, so the dollar metacharacter should not match it nor (except in multiline mode) a newline immediately before it. Setting this without G_REGEX_MULTILINE (at compile time) causes dollar never to match. This option affects only the behaviour of the dollar metacharacter, it does not affect "\Z" or "\z".

G_REGEX_MATCH_NOTEMPTY

An empty string is not considered to be a valid match if this option is set. If there are alternatives in the pattern, they are tried. If all the alternatives match the empty string, the entire match fails. For example, if the pattern "a?b?" is applied to a string not beginning with "a" or "b", it matches the empty string at the start of the string. With this flag set, this match is not valid, so GRegex searches further into the string for occurrences of "a" or "b".

G_REGEX_MATCH_PARTIAL

Turns on the partial matching feature, for more documentation on partial matching see g_match_info_is_partial_match().

G_REGEX_MATCH_NEWLINE_CR

Overrides the newline definition set when creating a new GRegex, setting the '\r' character as line terminator.

G_REGEX_MATCH_NEWLINE_LF

Overrides the newline definition set when creating a new GRegex, setting the '\n' character as line terminator.

G_REGEX_MATCH_NEWLINE_CRLF

Overrides the newline definition set when creating a new GRegex, setting the '\r\n' characters as line terminator.

G_REGEX_MATCH_NEWLINE_ANY

Overrides the newline definition set when creating a new GRegex, any newline character or character sequence is recognized.

Since 2.14


GRegex

typedef struct _GRegex GRegex;

A GRegex is the "compiled" form of a regular expression pattern. This structure is opaque and its fields cannot be accessed directly.

Since 2.14


GRegexEvalCallback ()

gboolean            (*GRegexEvalCallback)               (const GMatchInfo *match_info,
                                                         GString *result,
                                                         gpointer user_data);

Specifies the type of the function passed to g_regex_replace_eval(). It is called for each occurance of the pattern in the string passed to g_regex_replace_eval(), and it should append the replacement to result.

match_info :

the GMatchInfo generated by the match. Use g_match_info_get_regex() and g_match_info_get_string() if you need the GRegex or the matched string.

result :

a GString containing the new string

user_data :

user data passed to g_regex_replace_eval()

Returns :

FALSE to continue the replacement process, TRUE to stop it

Since 2.14


g_regex_new ()

GRegex *            g_regex_new                         (const gchar *pattern,
                                                         GRegexCompileFlags compile_options,
                                                         GRegexMatchFlags match_options,
                                                         GError **error);

Compiles the regular expression to an internal form, and does the initial setup of the GRegex structure.

pattern :

the regular expression

compile_options :

compile options for the regular expression, or 0

match_options :

match options for the regular expression, or 0

error :

return location for a GError

Returns :

a GRegex structure. Call g_regex_unref() when you are done with it

Since 2.14


g_regex_ref ()

GRegex *            g_regex_ref                         (GRegex *regex);

Increases reference count of regex by 1.

regex :

a GRegex

Returns :

regex

Since 2.14


g_regex_unref ()

void                g_regex_unref                       (GRegex *regex);

Decreases reference count of regex by 1. When reference count drops to zero, it frees all the memory associated with the regex structure.

regex :

a GRegex

Since 2.14


g_regex_get_pattern ()

const gchar *       g_regex_get_pattern                 (const GRegex *regex);

Gets the pattern string associated with regex, i.e. a copy of the string passed to g_regex_new().

regex :

a GRegex structure

Returns :

the pattern of regex

Since 2.14


g_regex_get_max_backref ()

gint                g_regex_get_max_backref             (const GRegex *regex);

Returns the number of the highest back reference in the pattern, or 0 if the pattern does not contain back references.

regex :

a GRegex

Returns :

the number of the highest back reference

Since 2.14


g_regex_get_capture_count ()

gint                g_regex_get_capture_count           (const GRegex *regex);

Returns the number of capturing subpatterns in the pattern.

regex :

a GRegex

Returns :

the number of capturing subpatterns

Since 2.14


g_regex_get_string_number ()

gint                g_regex_get_string_number           (const GRegex *regex,
                                                         const gchar *name);

Retrieves the number of the subexpression named name.

regex :

GRegex structure

name :

name of the subexpression

Returns :

The number of the subexpression or -1 if name does not exists

Since 2.14


g_regex_escape_string ()

gchar *             g_regex_escape_string               (const gchar *string,
                                                         gint length);

Escapes the special characters used for regular expressions in string, for instance "a.b*c" becomes "a\.b\*c". This function is useful to dynamically generate regular expressions.

string can contain nul characters that are replaced with "\0", in this case remember to specify the correct length of string in length.

string :

the string to escape

length :

the length of string, or -1 if string is nul-terminated

Returns :

a newly-allocated escaped string

Since 2.14


g_regex_match_simple ()

gboolean            g_regex_match_simple                (const gchar *pattern,
                                                         const gchar *string,
                                                         GRegexCompileFlags compile_options,
                                                         GRegexMatchFlags match_options);

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

Returns :

TRUE if the string matched, FALSE otherwise

Since 2.14


g_regex_match ()

gboolean            g_regex_match                       (const GRegex *regex,
                                                         const gchar *string,
                                                         GRegexMatchFlags match_options,
                                                         GMatchInfo **match_info);

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 GRegex structures.

A GMatchInfo structure, used to get information on the match, is stored in match_info if not NULL. Note that if match_info is not NULL 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().

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static void
print_uppercase_words (const gchar *string)
{
  /* Print all uppercase-only words. */
  GRegex *regex;
  GMatchInfo *match_info;
   
  regex = g_regex_new ("[A-Z]+", 0, 0, NULL);
  g_regex_match (regex, string, 0, &match_info);
  while (g_match_info_matches (match_info))
    {
      gchar *word = g_match_info_fetch (match_info, 0);
      g_print ("Found: %s\n", word);
      g_free (word);
      g_match_info_next (match_info, NULL);
    }
  g_match_info_free (match_info);
  g_regex_unref (regex);
}

string is not copied and is used in GMatchInfo internally. If you use any GMatchInfo method (except g_match_info_free()) after freeing or modifying string then the behaviour is undefined.

regex :

a GRegex structure from g_regex_new()

string :

the string to scan for matches

match_options :

match options

match_info :

pointer to location where to store the GMatchInfo, or NULL if you do not need it

Returns :

TRUE is the string matched, FALSE otherwise

Since 2.14


g_regex_match_full ()

gboolean            g_regex_match_full                  (const GRegex *regex,
                                                         const gchar *string,
                                                         gssize string_len,
                                                         gint start_position,
                                                         GRegexMatchFlags match_options,
                                                         GMatchInfo **match_info,
                                                         GError **error);

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 GRegex structures.

Setting start_position differs from just passing over a shortened string and setting G_REGEX_MATCH_NOTBOL in the case of a pattern that begins with any kind of lookbehind assertion, such as "\b".

A GMatchInfo structure, used to get information on the match, is stored in match_info if not NULL. Note that if match_info is not NULL 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 GMatchInfo internally. If you use any GMatchInfo 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().

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static void
print_uppercase_words (const gchar *string)
{
  /* Print all uppercase-only words. */
  GRegex *regex;
  GMatchInfo *match_info;
  GError *error = NULL;
   
  regex = g_regex_new ("[A-Z]+", 0, 0, NULL);
  g_regex_match_full (regex, string, -1, 0, 0, &match_info, &error);
  while (g_match_info_matches (match_info))
    {
      gchar *word = g_match_info_fetch (match_info, 0);
      g_print ("Found: %s\n", word);
      g_free (word);
      g_match_info_next (match_info, &error);
    }
  g_match_info_free (match_info);
  g_regex_unref (regex);
  if (error != NULL)
    {
      g_printerr ("Error while matching: %s\n", error->message);
      g_error_free (error);
    }
}

regex :

a GRegex structure from g_regex_new()

string :

the string to scan for matches

string_len :

the length of string, or -1 if string is nul-terminated

start_position :

starting index of the string to match

match_options :

match options

match_info :

pointer to location where to store the GMatchInfo, or NULL if you do not need it

error :

location to store the error occuring, or NULL to ignore errors

Returns :

TRUE is the string matched, FALSE otherwise

Since 2.14


g_regex_match_all ()

gboolean            g_regex_match_all                   (const GRegex *regex,
                                                         const gchar *string,
                                                         GRegexMatchFlags match_options,
                                                         GMatchInfo **match_info);

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 GMatchInfo structure, used to get information on the match, is stored in match_info if not NULL. Note that if match_info is not NULL 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 GMatchInfo internally. If you use any GMatchInfo method (except g_match_info_free()) after freeing or modifying string then the behaviour is undefined.

regex :

a GRegex structure from g_regex_new()

string :

the string to scan for matches

match_options :

match options

match_info :

pointer to location where to store the GMatchInfo, or NULL if you do not need it

Returns :

TRUE is the string matched, FALSE otherwise

Since 2.14


g_regex_match_all_full ()

gboolean            g_regex_match_all_full              (const GRegex *regex,
                                                         const gchar *string,
                                                         gssize string_len,
                                                         gint start_position,
                                                         GRegexMatchFlags match_options,
                                                         GMatchInfo **match_info,
                                                         GError **error);

Using the standard algorithm for regular expression matching only the longest match in the string is retrieved, it is not possibile 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 G_REGEX_MATCH_NOTBOL in the case of a pattern that begins with any kind of lookbehind assertion, such as "\b".

A GMatchInfo structure, used to get information on the match, is stored in match_info if not NULL. Note that if match_info is not NULL 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 GMatchInfo internally. If you use any GMatchInfo method (except g_match_info_free()) after freeing or modifying string then the behaviour is undefined.

regex :

a GRegex structure from g_regex_new()

string :

the string to scan for matches

string_len :

the length of string, or -1 if string is nul-terminated

start_position :

starting index of the string to match

match_options :

match options

match_info :

pointer to location where to store the GMatchInfo, or NULL if you do not need it

error :

location to store the error occuring, or NULL to ignore errors

Returns :

TRUE is the string matched, FALSE otherwise

Since 2.14


g_regex_split_simple ()

gchar **            g_regex_split_simple                (const gchar *pattern,
                                                         const gchar *string,
                                                         GRegexCompileFlags compile_options,
                                                         GRegexMatchFlags match_options);

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 a 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

Returns :

a NULL-terminated array of strings. Free it using g_strfreev()

Since 2.14


g_regex_split ()

gchar **            g_regex_split                       (const GRegex *regex,
                                                         const gchar *string,
                                                         GRegexMatchFlags match_options);

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 a 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".

regex :

a GRegex structure

string :

the string to split with the pattern

match_options :

match time option flags

Returns :

a NULL-terminated gchar ** array. Free it using g_strfreev()

Since 2.14


g_regex_split_full ()

gchar **            g_regex_split_full                  (const GRegex *regex,
                                                         const gchar *string,
                                                         gssize string_len,
                                                         gint start_position,
                                                         GRegexMatchFlags match_options,
                                                         gint max_tokens,
                                                         GError **error);

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 a 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 G_REGEX_MATCH_NOTBOL in the case of a pattern that begins with any kind of lookbehind assertion, such as "\b".

regex :

a GRegex structure

string :

the string to split with the pattern

string_len :

the length of string, or -1 if string is nul-terminated

start_position :

starting index of the string to match

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

error :

return location for a GError

Returns :

a NULL-terminated gchar ** array. Free it using g_strfreev()

Since 2.14


g_regex_replace ()

gchar *             g_regex_replace                     (const GRegex *regex,
                                                         const gchar *string,
                                                         gssize string_len,
                                                         gint start_position,
                                                         const gchar *replacement,
                                                         GRegexMatchFlags match_options,
                                                         GError **error);

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:

\l

Convert to lower case the next character

\u

Convert to upper case the next character

\L

Convert to lower case till \E

\U

Convert to upper case till \E

\E

End case modification

If you do not need to use backreferences use g_regex_replace_literal().

The replacement string must be UTF-8 encoded even if G_REGEX_RAW was passed to g_regex_new(). If you want to use not UTF-8 encoded stings you can use g_regex_replace_literal().

Setting start_position differs from just passing over a shortened string and setting G_REGEX_MATCH_NOTBOL in the case of a pattern that begins with any kind of lookbehind assertion, such as "\b".

regex :

a GRegex structure

string :

the string to perform matches against

string_len :

the length of string, or -1 if string is nul-terminated

start_position :

starting index of the string to match

replacement :

text to replace each match with

match_options :

options for the match

error :

location to store the error occuring, or NULL to ignore errors

Returns :

a newly allocated string containing the replacements

Since 2.14


g_regex_replace_literal ()

gchar *             g_regex_replace_literal             (const GRegex *regex,
                                                         const gchar *string,
                                                         gssize string_len,
                                                         gint start_position,
                                                         const gchar *replacement,
                                                         GRegexMatchFlags match_options,
                                                         GError **error);

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 G_REGEX_MATCH_NOTBOL in the case of a pattern that begins with any kind of lookbehind assertion, such as "\b".

regex :

a GRegex structure

string :

the string to perform matches against

string_len :

the length of string, or -1 if string is nul-terminated

start_position :

starting index of the string to match

replacement :

text to replace each match with

match_options :

options for the match

error :

location to store the error occuring, or NULL to ignore errors

Returns :

a newly allocated string containing the replacements

Since 2.14


g_regex_replace_eval ()

gchar *             g_regex_replace_eval                (const GRegex *regex,
                                                         const gchar *string,
                                                         gssize string_len,
                                                         gint start_position,
                                                         GRegexMatchFlags match_options,
                                                         GRegexEvalCallback eval,
                                                         gpointer user_data,
                                                         GError **error);

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 G_REGEX_MATCH_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:

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static gboolean 
eval_cb (const GMatchInfo *info,          
         GString          *res,
         gpointer          data)
{
  gchar *match;
  gchar *r;

   match = g_match_info_fetch (info, 0);
   r = g_hash_table_lookup ((GHashTable *)data, match);
   g_string_append (res, r);
   g_free (match);

   return FALSE;
}

/* ... */

GRegex *reg;
GHashTable *h;
gchar *res;

h = g_hash_table_new (g_str_hash, g_str_equal);

g_hash_table_insert (h, "1", "ONE");
g_hash_table_insert (h, "2", "TWO");
g_hash_table_insert (h, "3", "THREE");
g_hash_table_insert (h, "4", "FOUR");

reg = g_regex_new ("1|2|3|4", 0, 0, NULL);
res = g_regex_replace_eval (reg, text, -1, 0, 0, eval_cb, h, NULL);
g_hash_table_destroy (h);

/* ... */

regex :

a GRegex structure from g_regex_new()

string :

string to perform matches against

string_len :

the length of string, or -1 if string is nul-terminated

start_position :

starting index of the string to match

match_options :

options for the match

eval :

a function to call for each match

user_data :

user data to pass to the function

error :

location to store the error occuring, or NULL to ignore errors

Returns :

a newly allocated string containing the replacements

Since 2.14


g_regex_check_replacement ()

gboolean            g_regex_check_replacement           (const gchar *replacement,
                                                         gboolean *has_references,
                                                         GError **error);

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 NULL 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 GMatchInfo object.

replacement :

the replacement string

has_references :

location to store information about references in replacement or NULL

error :

location to store error

Returns :

whether replacement is a valid replacement string

Since 2.14


GMatchInfo

typedef struct _GMatchInfo GMatchInfo;

GMatchInfo is used to retrieve information about the regular expression match which created it. This structure is opaque and its fields cannot be accessed directly.

Since 2.14


g_match_info_get_regex ()

GRegex *            g_match_info_get_regex              (const GMatchInfo *match_info);

Returns GRegex object used in match_info. It belongs to Glib and must not be freed. Use g_regex_ref() if you need to keep it after you free match_info object.

match_info :

a GMatchInfo

Returns :

GRegex object used in match_info

Since 2.14


g_match_info_get_string ()

const gchar *       g_match_info_get_string             (const GMatchInfo *match_info);

Returns the string searched with match_info. This is the string passed to g_regex_match() or g_regex_replace() so you may not free it before calling this function.

match_info :

a GMatchInfo

Returns :

the string searched with match_info

Since 2.14


g_match_info_free ()

void                g_match_info_free                   (GMatchInfo *match_info);

Frees all the memory associated with the GMatchInfo structure.

match_info :

a GMatchInfo

Since 2.14


g_match_info_matches ()

gboolean            g_match_info_matches                (const GMatchInfo *match_info);

Returns whether the previous match operation succeeded.

match_info :

a GMatchInfo structure

Returns :

TRUE if the previous match operation succeeded, FALSE otherwise

Since 2.14


g_match_info_next ()

gboolean            g_match_info_next                   (GMatchInfo *match_info,
                                                         GError **error);

Scans for the next match using the same parameters of the previous call to g_regex_match_full() or g_regex_match() that returned match_info.

The match is done on the string passed to the match function, so you cannot free it before calling this function.

match_info :

a GMatchInfo structure

error :

location to store the error occuring, or NULL to ignore errors

Returns :

TRUE is the string matched, FALSE otherwise

Since 2.14


g_match_info_get_match_count ()

gint                g_match_info_get_match_count        (const GMatchInfo *match_info);

Retrieves the number of matched substrings (including substring 0, that is the whole matched text), so 1 is returned if the pattern has no substrings in it and 0 is returned if the match failed.

If the last match was obtained using the DFA algorithm, that is using g_regex_match_all() or g_regex_match_all_full(), the retrieved count is not that of the number of capturing parentheses but that of the number of matched substrings.

match_info :

a GMatchInfo structure

Returns :

Number of matched substrings, or -1 if an error occurred

Since 2.14


g_match_info_is_partial_match ()

gboolean            g_match_info_is_partial_match       (const GMatchInfo *match_info);

Usually if the string passed to g_regex_match*() matches as far as it goes, but is too short to match the entire pattern, FALSE is returned. There are circumstances where it might be helpful to distinguish this case from other cases in which there is no match.

Consider, for example, an application where a human is required to type in data for a field with specific formatting requirements. An example might be a date in the form ddmmmyy, defined by the pattern "^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$". If the application sees the user’s keystrokes one by one, and can check that what has been typed so far is potentially valid, it is able to raise an error as soon as a mistake is made.

GRegex supports the concept of partial matching by means of the G_REGEX_MATCH_PARTIAL flag. When this is set the return code for g_regex_match() or g_regex_match_full() is, as usual, TRUE for a complete match, FALSE otherwise. But, when these functions return FALSE, you can check if the match was partial calling g_match_info_is_partial_match().

When using partial matching you cannot use g_match_info_fetch*().

Because of the way certain internal optimizations are implemented the partial matching algorithm cannot be used with all patterns. So repeated single characters such as "a{2,4}" and repeated single meta-sequences such as "\d+" are not permitted if the maximum number of occurrences is greater than one. Optional items such as "\d?" (where the maximum is one) are permitted. Quantifiers with any values are permitted after parentheses, so the invalid examples above can be coded thus "(a){2,4}" and "(\d)+". If G_REGEX_MATCH_PARTIAL is set for a pattern that does not conform to the restrictions, matching functions return an error.

match_info :

a GMatchInfo structure

Returns :

TRUE if the match was partial, FALSE otherwise

Since 2.14


g_match_info_expand_references ()

gchar *             g_match_info_expand_references      (const GMatchInfo *match_info,
                                                         const gchar *string_to_expand,
                                                         GError **error);

Returns a new string containing the text in string_to_expand with references and escape sequences expanded. References refer to the last match done with string against regex and have the same syntax used by g_regex_replace().

The string_to_expand must be UTF-8 encoded even if G_REGEX_RAW was passed to g_regex_new().

The backreferences are extracted from the string passed to the match function, so you cannot call this function after freeing the string.

match_info may be NULL in which case string_to_expand must not contain references. For instance "foo\n" does not refer to an actual pattern and '\n' merely will be replaced with \n character, while to expand "\0" (whole match) one needs the result of a match. Use g_regex_check_replacement() to find out whether string_to_expand contains references.

match_info :

a GMatchInfo or NULL

string_to_expand :

the string to expand

error :

location to store the error occuring, or NULL to ignore errors

Returns :

the expanded string, or NULL if an error occurred

Since 2.14


g_match_info_fetch ()

gchar *             g_match_info_fetch                  (const GMatchInfo *match_info,
                                                         gint match_num);

Retrieves the text matching the match_num'th capturing parentheses. 0 is the full text of the match, 1 is the first paren set, 2 the second, and so on.

If match_num is a valid sub pattern but it didn't match anything (e.g. sub pattern 1, matching "b" against "(a)?b") then an empty string is returned.

If the match was obtained using the DFA algorithm, that is using g_regex_match_all() or g_regex_match_all_full(), the retrieved string is not that of a set of parentheses but that of a matched substring. Substrings are matched in reverse order of length, so 0 is the longest match.

The string is fetched from the string passed to the match function, so you cannot call this function after freeing the string.

match_info :

GMatchInfo structure

match_num :

number of the sub expression

Returns :

The matched substring, or NULL if an error occurred. You have to free the string yourself

Since 2.14


g_match_info_fetch_pos ()

gboolean            g_match_info_fetch_pos              (const GMatchInfo *match_info,
                                                         gint match_num,
                                                         gint *start_pos,
                                                         gint *end_pos);

Retrieves the position in bytes of the match_num'th capturing parentheses. 0 is the full text of the match, 1 is the first paren set, 2 the second, and so on.

If match_num is a valid sub pattern but it didn't match anything (e.g. sub pattern 1, matching "b" against "(a)?b") then start_pos and end_pos are set to -1 and TRUE is returned.

If the match was obtained using the DFA algorithm, that is using g_regex_match_all() or g_regex_match_all_full(), the retrieved position is not that of a set of parentheses but that of a matched substring. Substrings are matched in reverse order of length, so 0 is the longest match.

match_info :

GMatchInfo structure

match_num :

number of the sub expression

start_pos :

pointer to location where to store the start position

end_pos :

pointer to location where to store the end position

Returns :

TRUE if the position was fetched, FALSE otherwise. If the position cannot be fetched, start_pos and end_pos are left unchanged

Since 2.14


g_match_info_fetch_named ()

gchar *             g_match_info_fetch_named            (const GMatchInfo *match_info,
                                                         const gchar *name);

Retrieves the text matching the capturing parentheses named name.

If name is a valid sub pattern name but it didn't match anything (e.g. sub pattern "X", matching "b" against "(?P<X>a)?b") then an empty string is returned.

The string is fetched from the string passed to the match function, so you cannot call this function after freeing the string.

match_info :

GMatchInfo structure

name :

name of the subexpression

Returns :

The matched substring, or NULL if an error occurred. You have to free the string yourself

Since 2.14


g_match_info_fetch_named_pos ()

gboolean            g_match_info_fetch_named_pos        (const GMatchInfo *match_info,
                                                         const gchar *name,
                                                         gint *start_pos,
                                                         gint *end_pos);

Retrieves the position in bytes of the capturing parentheses named name.

If name is a valid sub pattern name but it didn't match anything (e.g. sub pattern "X", matching "b" against "(?P<X>a)?b") then start_pos and end_pos are set to -1 and TRUE is returned.

match_info :

GMatchInfo structure

name :

name of the subexpression

start_pos :

pointer to location where to store the start position

end_pos :

pointer to location where to store the end position

Returns :

TRUE if the position was fetched, FALSE otherwise. If the position cannot be fetched, start_pos and end_pos are left unchanged

Since 2.14


g_match_info_fetch_all ()

gchar **            g_match_info_fetch_all              (const GMatchInfo *match_info);

Bundles up pointers to each of the matching substrings from a match and stores them in an array of gchar pointers. The first element in the returned array is the match number 0, i.e. the entire matched text.

If a sub pattern didn't match anything (e.g. sub pattern 1, matching "b" against "(a)?b") then an empty string is inserted.

If the last match was obtained using the DFA algorithm, that is using g_regex_match_all() or g_regex_match_all_full(), the retrieved strings are not that matched by sets of parentheses but that of the matched substring. Substrings are matched in reverse order of length, so the first one is the longest match.

The strings are fetched from the string passed to the match function, so you cannot call this function after freeing the string.

match_info :

a GMatchInfo structure

Returns :

a NULL-terminated array of gchar * pointers. It must be freed using g_strfreev(). If the previous match failed NULL is returned

Since 2.14