How do I read from a file into a char*

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How do I read from a file into a char*

 
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  #1
Nov 26th, 2007
I need to read a file one word at a time. When I read the word it needs to be stored in a char* so I can pass it into my hash function. Whenever I try getline or infile>> my program just crashes. could someone please tell me what I need to use for this?
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Re: How do I read from a file into a char*

 
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Nov 26th, 2007
>could someone please tell me what I need to use for this?
Something besides char* because you obviously don't know what you're doing. I'd suggest using the string class, then you can use the c_str member function to get a pointer to const char for your hash function.
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Re: How do I read from a file into a char*

 
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  #3
Nov 26th, 2007
I already tried that but then the compiler spits out
cannot convert parameter 1 from 'const char *' to 'char *'
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Re: How do I read from a file into a char*

 
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  #4
Nov 26th, 2007
Do you know what a std::string is?
Last edited by iamthwee; Nov 26th, 2007 at 5:23 pm.
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Re: How do I read from a file into a char*

 
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Nov 26th, 2007
The string I was using was declared as an std::string, I just get that error when I try to compile.
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Re: How do I read from a file into a char*

 
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  #6
Nov 26th, 2007
Can you post your code along with a sample of your input file.
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Re: How do I read from a file into a char*

 
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Nov 26th, 2007
C++ Syntax (Toggle Plain Text) 
  1. 	std::string tmp;     //temp string value
  2. 	char* temp="";  //Temp value to hold strings
  3. 	ifstream dict, input; //input files for the dictionary file and the article file
  4. 	ofstream outfile;      //outfile file
  5. 	dict.open("words08k.txt", ios::in);
  6. 	while (!dict.eof())
  7. 	{
  8. 		dict.getline(str,20);
  9. 		hsh.insert(temp);
  10. 	}

This is without using the std:string, it compiles correctly this way, but crashes when it reaches dict.getline . the input file is a text file with a word on each line.

a simple example is

ahead
angst
angular


I know my hash functions work fine, I've tested them, I just need a way to get my input into a char* variable before I pass it to the hash function.
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Re: How do I read from a file into a char*

 
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  #8
Nov 26th, 2007
I feel like an idiot, I figured out the problem. I'm really sorry for wasting you guys time on this.
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Re: How do I read from a file into a char*

 
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  #9
Nov 26th, 2007
on line 1 you have
cpp Syntax (Toggle Plain Text) 
  1. 	char* temp="";  //Temp value to hold strings
but, I think that you should assign this pointer to some memory before you use it, i.e. something like
cpp Syntax (Toggle Plain Text) 
  1. char *temp = new char;
Also, you have
cpp Syntax (Toggle Plain Text) 
  1. dict.getline(str,20);
  2. hsh.insert(temp);

but, you don't declare str at any point?

If you fix these bits then you might have more luck.
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Re: How do I read from a file into a char*

 
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  #10
Nov 26th, 2007
Sorry, I think I was posting that reply as you were posting yours. Glad you fixed your code :-)
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