trusty (7) regex.h.7posix.gz

NAME

       regex.h - regular expression matching types

SYNOPSIS

       #include <regex.h>

DESCRIPTION

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

       The structure type regex_t shall contain at least the following member:

              size_t    re_nsub    Number of parenthesized subexpressions.

       The type size_t shall be defined as described in <sys/types.h> .

       The type regoff_t shall be defined as a signed integer type that can hold the largest value that  can  be
       stored  in  either a type off_t or type ssize_t. The structure type regmatch_t shall contain 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.

       Values for the cflags parameter to the regcomp() function are as follows:

       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>.

       Values for the eflags parameter to the regexec() function are as follows:

       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 following constants shall be defined 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 '\' 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.

       REG_ENOSYS
              Reserved.

       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

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       <sys/types.h>  , the System Interfaces volume of IEEE Std 1003.1-2001, regcomp(), the Shell and Utilities
       volume of IEEE Std 1003.1-2001

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
       Standard  for  Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers,
       Inc  and  The  Open Group. 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.opengroup.org/unix/online.html .