PROLOG | NAME | SYNOPSIS | DESCRIPTION | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

regex.h(0P)               POSIX Programmer's Manual              regex.h(0P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior), or
       the interface may not be implemented on Linux.

NAME         top

       regex.h — regular expression matching types

SYNOPSIS         top

       #include <regex.h>

DESCRIPTION         top

       The <regex.h> header shall define the structures and symbolic
       constants used by the regcomp(), regexec(), regerror(), and regfree()
       functions.

       The <regex.h> header shall define the regex_t structure type, which
       shall include at least the following member:

           size_t    re_nsub    Number of parenthesized subexpressions.

       The <regex.h> header shall define the size_t type as described in
       <sys/types.h>.

       The <regex.h> header shall define the regoff_t type as a signed
       integer type that can hold the largest value that can be stored in
       either a ptrdiff_t type or a ssize_t type.

       The <regex.h> header shall define the regmatch_t structure type,
       which shall include at least the following members:

           regoff_t    rm_so    Byte offset from start of string
                                to start of substring.
           regoff_t    rm_eo    Byte offset from start of string of the
                                first character after the end of substring.

       The <regex.h> header shall define the following symbolic constants
       for the cflags parameter to the regcomp() function:

       REG_EXTENDED  Use Extended Regular Expressions.

       REG_ICASE     Ignore case in match.

       REG_NOSUB     Report only success or fail in regexec().

       REG_NEWLINE   Change the handling of <newline>.

       The <regex.h> header shall define the following symbolic constants
       for the eflags parameter to the regexec() function:

       REG_NOTBOL    The <circumflex> character ('^'), when taken as a
                     special character, does not match the beginning of
                     string.

       REG_NOTEOL    The <dollar-sign> ('$'), when taken as a special
                     character, does not match the end of string.

       The <regex.h> header shall define the following symbolic constants as
       error return values:

       REG_NOMATCH   regexec() failed to match.

       REG_BADPAT    Invalid regular expression.

       REG_ECOLLATE  Invalid collating element referenced.

       REG_ECTYPE    Invalid character class type referenced.

       REG_EESCAPE   Trailing <backslash> character in pattern.

       REG_ESUBREG   Number in \digit invalid or in error.

       REG_EBRACK    "[]" imbalance.

       REG_EPAREN    "\(\)" or "()" imbalance.

       REG_EBRACE    "\{\}" imbalance.

       REG_BADBR     Content of "\{\}" invalid: not a number, number too
                     large, more than two numbers, first larger than second.

       REG_ERANGE    Invalid endpoint in range expression.

       REG_ESPACE    Out of memory.

       REG_BADRPT    '?', '*', or '+' not preceded by valid regular
                     expression.

       The following shall be declared as functions and may also be defined
       as macros. Function prototypes shall be provided.

           int    regcomp(regex_t *restrict, const char *restrict, int);
           size_t regerror(int, const regex_t *restrict, char *restrict, size_t);
           int    regexec(const regex_t *restrict, const char *restrict, size_t,
                      regmatch_t [restrict], int);
           void   regfree(regex_t *);

       The implementation may define additional macros or constants using
       names beginning with REG_.

       The following sections are informative.

APPLICATION USAGE         top

       None.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       sys_types.h(0p)

       The System Interfaces volume of POSIX.1‐2008, regcomp(3p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) In the event of any discrepancy between this version and
       the original IEEE and The Open Group Standard, the original IEEE and
       The Open Group Standard is the referee document. The original
       Standard can be obtained online at http://www.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                         regex.h(0P)

Pages that refer to this page: regcomp(3p)