regex.h(0p)

1<regex.h>(0P)              POSIX Programmer's Manual             <regex.h>(0P)
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NAME

6       regex.h - regular expression matching types
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SYNOPSIS

9       #include <regex.h>
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DESCRIPTION

12       The <regex.h> header shall define the structures and symbolic constants
13       used by the regcomp(), regexec(), regerror(), and regfree() functions.
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15       The structure type regex_t shall contain at least the following member:
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18              size_t    re_nsub    Number of parenthesized subexpressions.
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20       The type size_t shall be defined as described in <sys/types.h> .
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22       The type regoff_t shall be defined as a signed integer  type  that  can
23       hold  the  largest  value  that can be stored in either a type off_t or
24       type ssize_t. The structure type regmatch_t shall contain at least  the
25       following members:
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28              regoff_t    rm_so    Byte offset from start of string
29                                   to start of substring.
30              regoff_t    rm_eo    Byte offset from start of string of the
31                                   first character after the end of substring.
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33       Values  for  the cflags parameter to the regcomp() function are as fol‐
34       lows:
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36       REG_EXTENDED
37              Use Extended Regular Expressions.
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39       REG_ICASE
40              Ignore case in match.
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42       REG_NOSUB
43              Report only success or fail in regexec().
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45       REG_NEWLINE
46              Change the handling of <newline>.
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49       Values for the eflags parameter to the regexec() function are  as  fol‐
50       lows:
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52       REG_NOTBOL
53              The  circumflex character ( '^' ), when taken as a special char‐
54              acter, does not match the beginning of string.
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56       REG_NOTEOL
57              The dollar sign ( '$' ), when taken as a special character, does
58              not match the end of string.
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61       The following constants shall be defined as error return values:
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63       REG_NOMATCH
64              regexec() failed to match.
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66       REG_BADPAT
67              Invalid regular expression.
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69       REG_ECOLLATE
70              Invalid collating element referenced.
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72       REG_ECTYPE
73              Invalid character class type referenced.
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75       REG_EESCAPE
76              Trailing '\' in pattern.
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78       REG_ESUBREG
79              Number in \digit invalid or in error.
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81       REG_EBRACK
82              "[]" imbalance.
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84       REG_EPAREN
85              "\(\)" or "()" imbalance.
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87       REG_EBRACE
88              "\{\}" imbalance.
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90       REG_BADBR
91              Content  of "\{\}" invalid: not a number, number too large, more
92              than two numbers, first larger than second.
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94       REG_ERANGE
95              Invalid endpoint in range expression.
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97       REG_ESPACE
98              Out of memory.
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100       REG_BADRPT
101              '?', '*', or '+' not preceded by valid regular expression.
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103       REG_ENOSYS
104              Reserved.
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107       The following shall be declared as functions and may also be defined as
108       macros. Function prototypes shall be provided.
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111              int    regcomp(regex_t *restrict, const char *restrict, int);
112              size_t regerror(int, const regex_t *restrict, char *restrict, size_t);
113              int    regexec(const regex_t *restrict, const char *restrict, size_t,
114                         regmatch_t[restrict], int);
115              void   regfree(regex_t *);
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117       The  implementation  may  define  additional  macros or constants using
118       names beginning with REG_.
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120       The following sections are informative.
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APPLICATION USAGE

123       None.
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RATIONALE

126       None.
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FUTURE DIRECTIONS

129       None.
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COPYRIGHT

136       Portions  of  this text are reprinted and reproduced in electronic form
137       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
138       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
139       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  of
140       Electrical  and  Electronics  Engineers, Inc and The Open Group. In the
141       event of any discrepancy between this version and the original IEEE and
142       The  Open Group Standard, the original IEEE and The Open Group Standard
143       is the referee document. The original Standard can be  obtained  online
144       at http://www.opengroup.org/unix/online.html .
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148IEEE/The Open Group                  2003                        <regex.h>(0P)