Manual Reference Pages  - <regex.h> (P)

PROLOG

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.

CONTENTS

Name
Synopsis
Description
Application Usage
Rationale
Future Directions
See Also
Copyright

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 ’#146; 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 .


IEEE/The Open Group <regex.h> (P) 2003
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