REGEX.H(3HEAD)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 fol‐
lows:
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 \fIdigit 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 expres‐
sion.
REG_ENOSYS
Reserved.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌────────────────────┬─────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼─────────────────┤
│Interface Stability │ Standard │
└────────────────────┴─────────────────┘
SEE ALSOregcomp(3C), types.h(3HEAD), attributes(5), standards(5)
Sep 9, 2004 REGEX.H(3HEAD)
