[英]Array of structures and using variables of pointer to functions
Basically I want to input a string of text and if it matches with the string on the structure (*cmd_name), the program will then call and execute the function that corresponds to it. 基本上,我想输入文本字符串,如果它与结构(* cmd_name)上的字符串匹配,则程序将调用并执行与之对应的函数。 Here's my attempt:
这是我的尝试:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void new_cmd()
{
printf("You entered new_cmd function!");
}
void close_cmd()
{
printf("You entered close_cmd function!");
}
void open_cmd()
{
printf("You entered open_cmd function!");
}
void close_all_cmd()
{
printf("You entered the close_all_cmd function!");
}
struct{
char *cmd_name;
void (*cmd_pointer)(void); //variable of a pointer to a function
}file_cmd[]= { {"new", new_cmd},
{"open", open_cmd},
{"close", close_cmd},
{"close all", close_all_cmd}};
int main()
{
int i;
char my_string[15];
scanf("%s",my_string);
for(i=0; i<4;i++)
if(file_cmd[i].cmd_name == my_string) //matching the string
{
file_cmd[i].cmd_pointer(); //possible mistake here, trying to open the function
break;
}
return 0;
}
Whenever I test this and write on the command line "new" or any string, the program doesn't execute at all and exits. 每当我对此进行测试并在命令行“ new”或任何字符串上进行编写时,该程序根本不会执行并退出。
You can not compare strings using ==
, you have to use strcmp()
. 您不能使用
==
比较字符串 ,而必须使用strcmp()
。
That said, scanf("%s",my_string);
也就是说,
scanf("%s",my_string);
should better be scanf("%14s",my_string);
最好是
scanf("%14s",my_string);
to avoid buffer overlow by longer-than-expected input. 避免由于输入超出预期而导致缓冲区过低。 Also, you should always check the return value of
scanf()
to ensure success. 另外,您应始终检查
scanf()
的返回值以确保成功。
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