reading from a 2d array

This is a discussion on reading from a 2d array within the C Programming forums, part of the General Programming Boards category; I want to read from a 2d array which has strings in it. The thing is that the file seems ...

  1. #1
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    reading from a 2d array

    I want to read from a 2d array which has strings in it. The thing is that the file seems to get created but when i am trying to read from the array has nothing stored in the file. The file is empty even after the write function. Please let me know where i am going wrong.

    [insert]
    Code:
    #include <stdlib.h>
    #include <stdio.h>
    #include <string.h>
    #include <time.h>
    
    #define MAX_WORD_LENGTH 31
    #define MAX_WORDS 50
    
    /* Function prototypes */
    int readFile(char* inputFileName, int* wordCount, char array[][MAX_WORD_LENGTH], int flag);
    //int qsort(char array[][MAX_WORD_LENGTH], int* wordCount);
    int writeToFile(char* outFileName, int wordCount, char array[][MAX_WORD_LENGTH]);
    //void printTime(time_t  begin);
    void usage(char* processName);
    // enter any other function prototype you may wish
    
    int main(int argc, char* argv[])
    {
    		char array[MAX_WORDS][MAX_WORD_LENGTH];
    
    		int wordCount = 0; 
    		
           	switch (argc)
    		{
    		case 3:
    			readFile(argv[1], &wordCount, array,0);
    			writeToFile(argv[2], wordCount, array);
    			break;
    		case 4:
    		{
    			if (strcmp(argv[1], "-s") == 0)
    			  {
    			   readFile(argv[2], &wordCount, array,1);
         		   writeToFile(argv[3], wordCount, array);
    			  }
    			else if (strcmp(argv[1], "-t") == 0)
    			  {
    			    readFile(argv[2], &wordCount, array, 2);
    			    writeToFile(argv[3], wordCount, array);
    			  }
    			else
    			  {
    			    usage(argv[0]);
    			  }
    			break;
    		}
    		case 5:
    		default:
    	        usage(argv[0]);
    	        break;
    
    		
    	}
    	return 0;
    }
    
    // Define all your functions here
    
    int readFile(char* inputFileName, int* wordCount, char array[][MAX_WORD_LENGTH], int flag)
    {
    	FILE *fp;
    	fp = fopen(inputFileName, "r");
    
    	if(fp == NULL)
    	{
    		printf("\n Unable to open the file. Aborting");
    		exit(EXIT_FAILURE);
    
    	}
    
    	while(fscanf(fp, "%s", array[(*wordCount)++]) > 0);
    
    		return 0;
    }
    
    int writeToFile(char* outFileName, int wordCount, char array[][MAX_WORD_LENGTH])
    {
    	int i = 0;
    	FILE *fp;
    	fp = fopen(outFileName, "w");
    
    	if(fp == NULL)
    	{
    		printf("\n Unable to open the file. Aborting");
    		exit(EXIT_FAILURE);
    	}
    	
    	for(i = 0; i< wordCount; i++)
    	{
    		fprintf(fp, "%s\n", array[i++]);
    	}
    
    	return 0;
    }
    
    void usage(char* processName)
    {
      printf("Usage %s [-s] [-t] inputFileName outputFileName\n", processName);
    }

  2. #2
    CSharpener vart's Avatar
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    you need to close files
    you increment i twice in your write loop
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  3. #3
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    Quote Originally Posted by vart View Post
    you need to close files
    you increment i twice in your write loop
    Thanks i got it working. But even if i was incrementing 'i' twice shouldnt have some of the alternate strings been written or was it because of my not closing the file.

  4. #4
    CSharpener vart's Avatar
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    Quote Originally Posted by roaan View Post
    Thanks i got it working. But even if i was incrementing 'i' twice shouldnt have some of the alternate strings been written or was it because of my not closing the file.
    due to buffering you may not see changes in the file till you close file. Probably you tried to check file without closing the program...
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  5. #5
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    Also can i use the qsort function defined in c to sort the elements of a 2d array which are strings.

    qsort - C++ Reference

  6. #6
    CSharpener vart's Avatar
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    Quote Originally Posted by roaan View Post
    Also can i use the qsort function defined in c to sort the elements of a 2d array which are strings.

    qsort - C++ Reference
    if this is a question - the answer is yes
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

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