Function execution question

Hi.

I`m working on an application where i receive a function name and some parameters from a socket, and i have to execute the corresponding function. For example if i receive the string "hello_world" then i have to execute the function hello_world() located let`s say in service.c.

I`ve red the documentation of the dlopen function, but it isn`t good for me, because i compile the service.c file with my application, it is not an external object file.

Every suggestion is welcome.

Thanks

Yep... find a better way of doing this.

C is not going to let you execute a function by naming it in a string...

You can however use that string as a "menu selection" and call the function indirectly...

Code:

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if (!strcmp(str,"Hello_World"))
  hello_world();

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Yes, i thought about this solution i just wanted to know if exists any other solution to automate this part, because the other way if i invent a new function every time i have to come back, and add it manually. Not that this would be a big problem...:)

Thanks

Quote:

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Originally Posted by raczzoli

Yes, i thought about this solution i just wanted to know if exists any other solution to automate this part, because the other way if i invent a new function every time i have to come back, and add it manually. Not that this would be a big problem...

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You can map strings to function pointers such that you can search for the string, obtain the function pointer, then call the function. This way, you just need to modify the contents of the data structure instead of adding another branch to an if-else chain.

Quote:

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Originally Posted by laserlight

You can map strings to function pointers such that you can search for the string, obtain the function pointer, then call the function. This way, you just need to modify the contents of the data structure instead of adding another branch to an if-else chain.

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A very basic example of this would be:

Code:

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void  myHello(void);
void  myGoodBye(void);

int main(void){

        //create framework for function table
        struct myFunctionTable{
                char *myName;
                void (*myFunction)(void);
        };

        //make function table, aka array
        myFunctionTable FunctionTable[]={{"Hello", &myHello}, {"GoodBye", &myGoodBye}};

        char myAnswer[10];


        printf("Which function to run?");
        scanf("%s", myAnswer);

        //find and run function
        for(int i = 0; i < (sizeof(FunctionTable) / sizeof(myFunctionTable));i++){
                if(strcmp(FunctionTable[i].myName,myAnswer)==0){
                        FunctionTable[i].myFunction ();
                        break;
                }
        }
        getchar();
        getchar();
        return (0);
}
//Implement functions
void myHello(void){
        printf("Hello World\n");
}
void myGoodBye(void){
        printf("GoodBye World\n");
}

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