vstring.h

[詳解]

#ifndef _VSTRING_H_INCLUDED_
#define _VSTRING_H_INCLUDED_

/*++
/* NAME
/*  vstring 3h
/* SUMMARY
/*  arbitrary-length string manager
/* SYNOPSIS
/*  #include "vstring.h"
/* DESCRIPTION
/* .nf

 /*
  * System library.
  */
#include <stdarg.h>

 /*
  * Utility library.
  */
#include <vbuf.h>
#include <check_arg.h>

 /*
  * We can't allow bare VBUFs in the interface, because VSTRINGs have a
  * specific initialization and destruction sequence.
  */
typedef struct VSTRING {
    VBUF    vbuf;
    ssize_t maxlen;
} VSTRING;

extern VSTRING *vstring_alloc(ssize_t);
extern void vstring_ctl(VSTRING *,...);
extern VSTRING *vstring_truncate(VSTRING *, ssize_t);
extern VSTRING *vstring_free(VSTRING *);
extern VSTRING *vstring_strcpy(VSTRING *, const char *);
extern VSTRING *vstring_strncpy(VSTRING *, const char *, ssize_t);
extern VSTRING *vstring_strcat(VSTRING *, const char *);
extern VSTRING *vstring_strncat(VSTRING *, const char *, ssize_t);
extern VSTRING *vstring_memcpy(VSTRING *, const char *, ssize_t);
extern VSTRING *vstring_memcat(VSTRING *, const char *, ssize_t);
extern char *vstring_memchr(VSTRING *, int);
extern VSTRING *vstring_insert(VSTRING *, ssize_t, const char *, ssize_t);
extern VSTRING *vstring_prepend(VSTRING *, const char *, ssize_t);
extern VSTRING *PRINTFLIKE(2, 3) vstring_sprintf(VSTRING *, const char *,...);
extern VSTRING *PRINTFLIKE(2, 3) vstring_sprintf_append(VSTRING *, const char *,...);
extern VSTRING *PRINTFLIKE(2, 3) vstring_sprintf_prepend(VSTRING *, const char *,...);
extern char *vstring_export(VSTRING *);
extern VSTRING *vstring_import(char *);

/* Legacy API: constant plus type-unchecked argument. */
#define VSTRING_CTL_MAXLEN  1
#define VSTRING_CTL_EXACT   2
#define VSTRING_CTL_END     0

/* Safer API: type-checked arguments. */
#define CA_VSTRING_CTL_END      VSTRING_CTL_END
#define CA_VSTRING_CTL_EXACT        VSTRING_CTL_EXACT
#define CA_VSTRING_CTL_MAXLEN(val)  VSTRING_CTL_MAXLEN, CHECK_VAL(VSTRING_CTL, ssize_t, (val))

CHECK_VAL_HELPER_DCL(VSTRING_CTL, ssize_t);

#define VSTRING_FLAG_EXACT  (1<<8)  /* exact allocation for tests */

 /*
  * Macros. Unsafe macros have UPPERCASE names.
  */
#define VSTRING_SPACE(vp, len)  ((vp)->vbuf.space(&(vp)->vbuf, (len)))
#define vstring_str(vp)     ((char *) (vp)->vbuf.data)
#define VSTRING_LEN(vp)     ((ssize_t) ((vp)->vbuf.ptr - (vp)->vbuf.data))
#define vstring_end(vp)     ((char *) (vp)->vbuf.ptr)
#define VSTRING_TERMINATE(vp)   do { \
                    *(vp)->vbuf.ptr = 0; \
                } while (0)
#define VSTRING_RESET(vp)   do { \
                    (vp)->vbuf.ptr = (vp)->vbuf.data; \
                    (vp)->vbuf.cnt = (vp)->vbuf.len; \
                } while (0)
#define VSTRING_ADDCH(vp, ch)   VBUF_PUT(&(vp)->vbuf, ch)
#define VSTRING_SKIP(vp)    do { \
                    while ((vp)->vbuf.cnt > 0 && *(vp)->vbuf.ptr) \
                        (vp)->vbuf.ptr++, (vp)->vbuf.cnt--; \
                } while (0)
#define vstring_avail(vp)   ((vp)->vbuf.cnt)

 /*
  * The following macro is not part of the public interface, because it can
  * really screw up a buffer by positioning past allocated memory.
  */
#define VSTRING_AT_OFFSET(vp, offset) do { \
    (vp)->vbuf.ptr = (vp)->vbuf.data + (offset); \
    (vp)->vbuf.cnt = (vp)->vbuf.len - (offset); \
    } while (0)

extern VSTRING *vstring_vsprintf(VSTRING *, const char *, va_list);
extern VSTRING *vstring_vsprintf_append(VSTRING *, const char *, va_list);

/* BUGS
/*  Auto-resizing may change the address of the string data in
/*  a vstring structure. Beware of dangling pointers.
/* HISTORY
/* .ad
/* .fi
/*  A vstring module appears in the UNPROTO software by Wietse Venema.
/* LICENSE
/* .ad
/* .fi
/*  The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*  Wietse Venema
/*  IBM T.J. Watson Research
/*  P.O. Box 704
/*  Yorktown Heights, NY 10598, USA
/*
/*  Wietse Venema
/*  Google, Inc.
/*  111 8th Avenue
/*  New York, NY 10011, USA
/*--*/

#endif