REGEX.H(3HEAD) Headers REGEX.H(3HEAD)

NAME

regex.h, regex - regular expression matching types

SYNOPSIS

#include <regex.h>

DESCRIPTION

The <regex.h> header defines the structures and symbolic constants
used by the regcomp(), regexec(), regerror(), and regfree()
functions. See regcomp(3C).


The structure type regex_t contains the following member:

size_t re_nsub number of parenthesized subexpressions


The type size_t is defined as described in <sys/types.h>. See
types.h(3HEAD).


The type regoff_t is 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 contains 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 character


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 are 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.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+

SEE ALSO

regcomp(3C), types.h(3HEAD), attributes(7), standards(7)

September 9, 2004 REGEX.H(3HEAD)