C - 将字符串拆分为字符串数组

Question

我不完全确定如何在C中执行此操作:

char* curToken = strtok(string, ";");
//curToken = "ls -l" we will say
//I need a array of strings containing "ls", "-l", and NULL for execvp()

我该怎么做呢？

Answer 1

既然你已经研究过strtok继续沿着相同的路径并使用space(' ')作为分隔符拆分你的字符串,那么使用一些东西realloc来增加包含要传递给的元素的数组的大小execvp.

请参阅下面的示例,但请记住,strtok它将修改传递给它的字符串.如果您不希望发生这种情况,则需要使用strcpy或类似功能复制原始字符串.

char    str[]= "ls -l";
char ** res  = NULL;
char *  p    = strtok (str, " ");
int n_spaces = 0, i;


/* split string and append tokens to 'res' */

while (p) {
  res = realloc (res, sizeof (char*) * ++n_spaces);

  if (res == NULL)
    exit (-1); /* memory allocation failed */

  res[n_spaces-1] = p;

  p = strtok (NULL, " ");
}

/* realloc one extra element for the last NULL */

res = realloc (res, sizeof (char*) * (n_spaces+1));
res[n_spaces] = 0;

/* print the result */

for (i = 0; i < (n_spaces+1); ++i)
  printf ("res[%d] = %s\n", i, res[i]);

/* free the memory allocated */

free (res);

res[0] = ls
res[1] = -l
res[2] = (null)

Answer 2

这是一个如何使用从MSDN借来的strtok的例子.

和相关的位,你需要多次调用它.该token字符*是你塞进一个数组的部分(你可以计算的那部分).

char string[] = "A string\tof ,,tokens\nand some  more tokens";
char seps[]   = " ,\t\n";
char *token;

int main( void )
{
    printf( "Tokens:\n" );
    /* Establish string and get the first token: */
    token = strtok( string, seps );
    while( token != NULL )
    {
        /* While there are tokens in "string" */
        printf( " %s\n", token );
        /* Get next token: */
        token = strtok( NULL, seps );
    }
}