Strtok()分段错误

Question

struct args
{
    char command[64];
    char args[2][64];
};

int argscount = 0;
struct args* arguments;
int buffersize = 64;
char *ptoken = NULL;
char input[buffersize];
char *pstr = NULL;



int a = read(0,input,buffersize);
pstr = input;
arguments = malloc(sizeof(struct args));        
if(a>0){  
    ptoken = strtok(&pstr," ");
    strcpy(arguments->command,ptoken);
    printf("TOKEN:%s\n", ptoken);
    while( ptoken != NULL ) {
        if(argscount > 1){break;}
        ptoken = strtok(NULL, ' ');
        strcpy(arguments->args[argscount],ptoken);
        argscount++;  
    }  
}

Answer 1

问题最有可能出现在

ptoken = strtok(&pstr," ");

strtok的第一个参数应该是

char *

您可以将其作为

char **

Answer 2

正如strtok所期望的那样，read不会返回以null结尾的字符串。您将需要在输入中分配一个额外的字节来添加'\0'。您可以查看read的返回值来查看读取了多少字节，然后将'\0'放在input[a]处。

int a = read(0,input,buffersize-1);
input[a] = '\0';

Answer 3

代码中的几个修复(和其他)。注释描述了我所做的更改：(如果定义了read()函数，它可能已经构建)还添加了main，只是为了通过错误进行编译。

#include <ansi_c.h>

 struct args
{
    char command[64];
    char args[2][64];
};

int argscount = 0;
struct args* arguments;
size_t buffersize = 64; //changed to size_t
char *ptoken = NULL;
char input[64];  //variable initializer not allowed, changed
char *pstr = NULL;

int read(int a, char *s, size_t size);


main(void)
{

    int a = read(0,input,buffersize);

pstr = input;
arguments = malloc(sizeof(struct args));        
if(a>0)
    {  
        ptoken = strtok(pstr," "); //changed &pstr to pstr
        strcpy(arguments->command,ptoken);
        printf("TOKEN:%s\n", ptoken);
        while( ptoken != NULL ) {
            if(argscount > 1){break;}
            ptoken = strtok(NULL, " "); //changed ' ' to " "
            strcpy(arguments->args[argscount],ptoken);
            argscount++;  
        }  
    }
}