How to parse char * between function?

[Dantoc]

Hi everyone,

I have question regarding parsing char* between function. I speak in program will more easy to understand.

//============
file.h
------
char *Name[1];
char A;

file.cpp
--------

main()
{
#include 'file.h'

functionA;
functionB;
}

functionA
{
Name[0]=A;
}

functionB
{
cout<<Name[0];
}

//==================

The process is in functionA but the display is in functionB, is it possible to parse char* between function?

Thanks.

BR,
Dan

[hamsterman]

void foo(char* p) {
   p[0] = 'x';
}

void bar(char* q) {
   cout << q[0];
}

int main() {
   char* ptr = new char[10];
   foo(ptr);
   bar(ptr);
}

[Dantoc]

It does not work because I am trying to use char array. the error show me can not convert from char[260] to char. need help.

void foo(char* p) {
char file[FILENAME_MAX];
ifstream inFile;

inFile.getline(file,FILENAME_MAX, ',');

p[0] = file;
}

void bar(char* q) {
cout << q[0];
}

int main() {
char* ptr = new char[10];
foo(ptr);
bar(ptr);
}


is it possible to do so? any other suggestion?

Thanks.

[hamsterman]

p[0] = file; says that you want the first character in whatever string p points to to be the file array. You probably want strcpy(p, file);

[Dantoc]

void foo(char* p);
void bar(char* q);

void foo(char* p)
{
char file[FILENAME_MAX];
ifstream inFile;

do{
cout<<"\nPlease enter a file name.";
cin.getline(file, FILENAME_MAX, '\n');
}while(file[0]==NULL);

cout<<"\nOpening file: "<<file;

inFile.getline(file,FILENAME_MAX, ',');
strcpy(p, file);
//p[0] = file;
}

void bar(char* q)
{
cout << q[0];
}

int main() {
char* ptr = new char[10];
foo(ptr);
bar(ptr);
}

//==================
Do you mean this? this does not display anything words. Please advise. Thanks.

[hamsterman]

In bar(), q is a string and q[0] is its first character, so there is no way you'd see a word there. Other than that, if you have some problems, maybe the fie is to blame.

By the way, condition file[0]==NULL is never going to be true (unless there is a special key combination to enter null character..).

[Dantoc]

my file content is looks like this:

group,input1,input2,input3,
groupA,1,2,3,

so my target is to read data from file and save into array so that i can call the array to display the data anytime. so my code is looks like this:

//================================
void read(char* p);
void print(char* q);

void read(char* p)
{
char file[FILENAME_MAX];
char name[FILENAME_MAX];
ifstream inFile;
int cnt=0;

do{
cout<<"\nPlease enter a file name.";
cin.getline(file, FILENAME_MAX, '\n');
}while(file[0]==NULL);

cout<<"\nOpening file: "<<file;

for(int i=0; i<8; i++)
{
inFile.getline(name,FILENAME_MAX, ',');
p[cnt]=name;
cnt++;
}

}

void bar(char* q)
{
cout <<"\n"<< q[0];
cout <<"\n"<< q[2];
cout <<"\n"<< q[3];
cout <<"\n"<< q[4];
cout <<"\n"<< q[5];
cout <<"\n"<< q[6];
cout <<"\n"<< q[7];

cout <<"\n"<< q[0];
cout <<"\n"<< q[4];
cout <<"\n"<< q[5];
cout <<"\n"<< q[6];

}

int main() {
char* ptr = new char[10];
foo(ptr);
bar(ptr);
}

//======================
expected display is:
group
input1
input2
input3
groupA
1
2
3
group
groupA
1
2

//=======================

above is my idea or any suggestion to do this? Please advide. I have been try for many method but it still cant display the output. Thanks.

[hamsterman]

Again, p[n] is a character. You cannot assign an array to it and you cannot print it and expect to get more than one character.
Compile this:

#include <iostream>
#include <fstream>
using namespace std;

void foo(char* p) {
   char file[FILENAME_MAX];
   ifstream inFile;

   cout<<"\nPlease enter a file name.";
   cin.getline(file, FILENAME_MAX, '\n');
   inFile.open(file);

   cout<<"\nOpening file: "<<file;
   inFile.getline(p,FILENAME_MAX, ',');
   inFile.close();
}

void bar(char* q) {
   cout <<"\n"<< q;
}

int main() {
   char* ptr = new char[FILENAME_MAX];
   foo(ptr);
   bar(ptr);
}

And see what you get. It should be the first line of your fie.
To divide the string, you can use strtok.
You'll need to use a char** then.
And when you post code, do use [code] tags.

[Dantoc]

Hi, i had try the code, there is nothing to display out. :(

[hamsterman]

whoops. I didn't open the file or even include fstream.. I just noticed that neither did you.. (should be good now)

[Dantoc]

yeah