如何从 strcpy 的函数返回一个 char* 数组并将其存储在另一个 char* 数组中？

如何解决如何从 strcpy 的函数返回一个 char* 数组并将其存储在另一个 char* 数组中？

我创建了一个 Strcpy 函数来将一个字符串复制到另一个字符串中。当两个 char[] 数组 通过它时它工作得很好，但是当传递 char* 数组时它会出现分段错误（核心转储）错误。如何解决？

#include <iostream>

using namespace std ;

char* Strcpy ( char* s1,const char* s2 )
{
while(*s2 != '\0')
{
*(s1)=*(s2);
s1++;
s2++;
}
*s1='\0';

return s1;
}

int main()
{

/*char t1[]="HelloWorld";  //it is working fine for both these arrays
char t2[]="TestString";*/

char* t1="HelloWorld";    //Segmentation fault
char* t2="TestString";

char* r=Strcpy(t1,t2);

cout<<r<<endl;

cout << t1;
}

解决方法

您的 strcpy 函数适用于这些的原因：

示例 1：

/*
 * Header prepended by linux kernel to each event.
 * Appears at the front of each packet in DLT_USB_LINUX captures.
 */
typedef struct _usb_header {
    uint64_t id;
    uint8_t event_type;
    uint8_t transfer_type;
    uint8_t endpoint_number;
    uint8_t device_address;
    uint16_t bus_id;
    char setup_flag;/*if !=0 the urb setup header is not present*/
    char data_flag; /*if !=0 no urb data is present*/
    int64_t ts_sec;
    int32_t ts_usec;
    int32_t status;
    uint32_t urb_len;
    uint32_t data_len; /* amount of urb data really present in this event*/
    pcap_usb_setup setup;
} pcap_usb_header;

而此处（示例 2）：

/*
 * USB setup header as defined in USB specification.
 * Appears at the front of each Control S-type packet in DLT_USB captures.
 */
typedef struct _usb_setup {
    uint8_t bmRequestType;
    uint8_t bRequest;
    uint16_t wValue;
    uint16_t wIndex;
    uint16_t wLength;
} pcap_usb_setup;

当 Strcpy() 尝试覆盖 BSS 段中的受保护数据时发生段错误。

有几种方法可以解决这个问题。如示例 1 所示，您可以在全局数据空间中为目标字符串分配足够的内存，或者在堆栈上分配内存，或者再次在堆中分配一些内存。

char t1[]="HelloWorld";  // you are defining arrays of characters in the data 
char t2[]="TestString";  // segment.  This are of memory has read/write access.
                         // You have effectively allocated and initiaized 
                         // 22 bytes of data in read/write memory. 

由于 strcpy() 返回一个指向目标字符串的指针，您已经拥有该指针，因此其返回值不是很有用，通常会被忽略。