Glad the forum is back... BIG question regarding function pointers and structs...

[criticalerror]

I am trying to get this program to work, when it runs, any command, aside from exit causes the function mylowercase
to run. I have no clue, as I have been looking at this for a few days and I cannot find where the problem is. Any help on this one would be huge.

 //String Processor with Array of Structures and Commands.cpp : Defines the entry point for the console application.
#include "stdafx.h"
#include <cstring>

struct String_Handler{
	char *name;
	char *message;
	char *(*mystringfunction)(char *,const char *);
};
char *mystrcopy(char *dst, const char *src){
	char *rez=dst;
	for(;(*dst=*src)!='\0';src++,dst++);
	return rez;
}
char *myuppercase(char *dst,const char *src){
	char *rez=dst;
	for(;*src!='\0';*dst=(*src>='a'&&*src<='z')?*src+('A'-'a'):*src,src++,dst++);
	*dst='\0';
	return rez;
}
char *mylowercase(char *dst, const char *src){
	char *rez=dst;
	for(;*src!='\0';*dst=(*src>='A'&&*src<='Z')?*src+('a'-'A'):*src,src++,dst++);
	*dst='\0';
	return rez;
}
char *myrighttrim(char *dst, const char *src){
	char *rez=dst;
	for(;*src!='\0'&& *src==' ';src++);
	for(;(*dst=*src)!='\0';src++,dst++);
	return rez;
}
char *myreverse(char *dst, const char *src){
	char current_char;
	char *rez=dst;
	if(*src!='\0'){
		current_char=*src;
		dst=myreverse(dst,src+1);
		*dst++=current_char;
		*dst='\0';
	}
	return dst;
}
int binary_search_iterative(const String_Handler sh_table[],int first_index,int last_index,char *comm){	
	int middle;

	while(first_index<=last_index){
		middle=(last_index+first_index)/2;
		if(strcmp(comm,sh_table[middle].name)==0) return middle;	//successfully found element!
		if(strcmp(comm,sh_table[middle].name)==-1)
			last_index=middle-1;
		else
			first_index=middle+1;
	}
	return -1;		//element not found!
}

bool string_processor(char *comm,char *dst, char *src, String_Handler sh_table[],int table_size){
	//for(int i=0;i<table_size&&strcmp(comm,sh_table[i].name)!=0;i++);
	int i;
	if(i=binary_search_iterative(sh_table,0,table_size-1,comm)!=-1){
		std::cout<<sh_table[i].message<<(sh_table[i].mystringfunction)(dst, src)<<std::endl;
		return true;
		}
	else
		return false;
}
void get_command(char *command){
	std::cout<<"Input command(copy,upper,lower,right,reverse or exit):";
	std::cin>>command;
	std::cout<<std::endl;
	return;
}

int main()
{
	String_Handler string_handler_table[5];
	
	string_handler_table[0].name="copy";
	string_handler_table[0].message="The copy of the string is: ";
	string_handler_table[0].mystringfunction=mystrcopy;

	string_handler_table[4].name="upper";
	string_handler_table[4].message="The upper case version of the string is: ";
	string_handler_table[4].mystringfunction=myuppercase;

	string_handler_table[1].name="lower";
	string_handler_table[1].message="The lower case version of the string is: ";
	string_handler_table[1].mystringfunction=mylowercase;
	
	string_handler_table[3].name="right";
	string_handler_table[3].message="The right trimmed version of the string is:";
	string_handler_table[3].mystringfunction=myrighttrim;

	string_handler_table[2].name="reverse";
	string_handler_table[2].message="The reversed version of the string is:";
	string_handler_table[2].mystringfunction=myreverse;

	char *str="             This is the test string!";
	char rez[100];
	char command[10]="";

	get_command(command);
	while(strcmp(command,"exit")!=0){
		if(!string_processor(command,rez,str,string_handler_table,sizeof string_handler_table/sizeof (String_Handler)))
			std::cout<<"Not a legal command!"<<std::endl;
		get_command(command);
	}
	return 0;
}

[MrWizard]

Okay found your problem...

This line is bad news!!

if(i=binary_search_iterative(sh_table,0,table_size-1,comm)!=-1)

I suppose its subtle but this is the root of a lot of problems. You set i = to a function and test it to -1. The function correctly returns the value and it does not equal -1 so it evalutes to true ( or 1 in this case ). You need to wrap your assignment in paranthesis to give correct order of precedence. Here ya go.

if( (i=binary_search_iterative(sh_table,0,table_size-1,comm))!=-1)

Now you have some other problems but that should get you on the right path. If you get stuck again let us know. Enjoy.

[criticalerror]

great, thank you so much, i knew it had to be something so small as assignment and order of operations, but I couldn't find it... sometimes it takes another set of eyes to find what is going on... Appreciate it! Thanks!

[criticalerror]

in the myreversestring function, I'm not sure on the type of loop sturcture to use... obviously the if is not going to cut it, but I thought it would be a place to start, just to see if it prints out the right character... any suggestions?

[Edward]

My first suggestion would be to avoid recursion for string processing. It's very wasteful, and an iterative approach is far easier to visualise.

char *myreverse(char *dst, const char *src)
{
    int srcloc = 0;
    int dstloc = 0;

    while (src[srcloc] != '\0')
        srcloc++;
    while (--srcloc >= 0)
        dst[dstloc++] = src[srcloc];
    dst[dstloc] = '\0';

    return dst;
}

[criticalerror]

Thanks!