最近研究发现，结构体还可以如同C++类一样构造使用，一时心血来潮写了个安全字符串结构，大家来看看，也请各位高手指点不足，谢谢啦。。 /* string.h */ #ifndef __STRING_H #define __STRING_H
#include "string.cpp"
#endif /* string.cpp */ typedef enum {FALSE=0,TRUE=1} BOOL;
typedef struct safe_string { /* variable */ char *contents; int buffer_size; /* construction */ void initalize(void); /* member function */ void buf_allocate(int); void buf_reallocate(int); void buf_release(void); BOOL autostring(const char *); BOOL getstring(const char *); int getlength(void); /* destory */ void destory(void); } string;
void safe_string::initalize(void) { contents=NULL; buffer_size=0; }
void safe_string::buf_allocate(int bufsize) { destory(); contents=(char *)malloc(bufsize); if(!contents) { printf("No memory for allocating a new string!\n"); printf("Press any key to exit.\n"); getch(); exit(1); } buffer_size=bufsize; }
void safe_string::buf_reallocate(int bufsize) { if(!contents) contents=(char *)malloc(bufsize); else contents=(char *)realloc(contents,bufsize); if(!contents) { printf("No memory for reallocating a new string!\n"); printf("Press any key to exit.\n"); getch(); exit(1); } buffer_size=bufsize; }
void safe_string::buf_release(void) { int len=getlength(); contents=(char *)realloc(contents,len+1); if(!contents) { printf("No memory for reallocating a string!\n"); printf("Press any key to exit.\n"); getch(); exit(1); } buffer_size=len+1; }
BOOL safe_string::autostring(const char *s) { if(!s) return FALSE; int len=strlen(s); buf_allocate(len+1); strcpy(contents,s); return TRUE; }
BOOL safe_string::getstring(const char *s) { if(!s) return FALSE; if(!contents) return FALSE; int len=strlen(s); if(len+1>buffer_size) return FALSE; else { strcpy(contents,s); return TRUE; } }
int safe_string::getlength(void) { char *p=contents; int len=0; while(*p++) len++; return len; }
void safe_string::destory(void) { if(contents) free(contents); } /* debug_string.cpp */ #include <stdio.h> #include <string.h> #include <stdlib.h> #include <conio.h>
#include "string.h"
int main() { string s; s.initalize(); s.autostring("Hello,world"); printf("%s,%d,%d\n",s.contents,s.buffer_size,s.getlength()); s.destory(); getch(); }
