regexp.3x (2010 09)

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regexp(3X) regexp(3X)

NAME

compile( ), step( ), advance( ) - regular expression compile and match routines

SYNOPSIS

#define INIT declarations

#define GETC() getc statements

#define PEEKC() peekc statements

#define UNGETC(c) ungetc statements

#define RETURN(pointer)

return statements

#define ERROR(val) error statements

#include <regexp.h>

char *compile(

char *instring,

char *expbuf,

const char *endbuf,

int eof

);

int step(const char *string, const char *expbuf);

int advance(const char *string, const char *expbuf);

extern char *loc1, *loc2, *locs;

extern int circf, sed, nbra;

Remarks

Features documented in this manual entry are obsolescent and may be removed in a future

HP-UX

release. Use of regcomp (3C) functions instead is recommended.

DESCRIPTION

These functions are general-purpose regular expression matching routines to be used in programs that

perform Basic Regular Expression (see regexp(5)) matching. These functions are deﬁned in

regexp.h>.

The functions

step() and advance() do pattern matching given a character string and a compiled

regular expression as input. compile() takes a Basic Regular Expression as input and produces a

compiled expression that can be used with step() and advance().

The interface to this ﬁle is unpleasantly complex. Programs that include this ﬁle must have the following

ﬁve macros declared before the

#include <regexp.h> statement. These macros are used by the

compile() routine.

GETC() Return the value of the next byte in the regular expression pattern. Successive calls to

GETC() should return successive bytes of the regular expression.

PEEKC() Return the next byte in the regular expression. Successive calls to PEEKC() should

return the same byte (which should also be the next byte returned by GETC().

UNGETC(c) Cause the argument c to be returned by the next call to GETC() (and PEEKC()). No

more than one byte of pushback is ever needed, and this byte is guaranteed to be the last

byte read by GETC(). The value of the macro UNGETC(c) is always ignored.

RETURN(pointer )

This macro is used on normal exit of the compile() routine. The value of the argu-

ment pointer is a pointer to the character after the last character of the compiled regular

expression. This is useful to programs that must manage memory allocation.

ERROR(val ) This is the abnormal return from the compile() routine. The argument val is an

error number (see table below for meanings). This call should never return.

Error Meaning

11 Range endpoint too large.

16 Bad number.

25 ‘‘\digit’’ out of range.

36 Illegal or missing delimiter.

41 No remembered search string.

HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1

Summary of content (4 pages)

PAGE 1
regexp(3X) regexp(3X) NAME compile( ), step( ), advance( ) - regular expression compile and match routines SYNOPSIS #define #define #define #define #define #define INIT declarations GETC() getc statements PEEKC() peekc statements UNGETC(c) ungetc statements RETURN(pointer) return statements ERROR(val) error statements #include
PAGE 2
regexp(3X) regexp(3X) 42 43 44 45 46 49 50 \( \) imbalance. Too many \(. More than 2 numbers given in \{ \}. } expected after \. First number exceeds second in \{ \}. [ ] imbalance. Regular expression overflow. The syntax of the compile() routine is as follows: compile(instring , expbuf , endbuf , eof) The first parameter instring is never used explicitly by the compile() routine, but is useful for programs that pass down different pointers to input characters.
PAGE 3
regexp(3X) regexp(3X) such as s/y*//g do not loop forever. The additional external variables sed and nbra are used for special purposes. EXTERNAL INFLUENCES Locale The LC_COLLATE category determines the collating sequence used in compiling and executing regular expressions. The LC_CTYPE category determines the interpretation of text as single and/or multi-byte characters, and the characters matched by character class expressions in regular expressions.
PAGE 4
(Notes) A (Notes) rA 4 Hewlett-Packard Company −1− HP-UX 11i Version 3: September 2010